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Joseph J. Molnar
Professor of Rural Sociology
Terry R. Hanson
Senior Research Associate
Leonard L. Lovshin
Professor of Fisheries and Allied Aquacultures
with
German Cerezo, Auburn University
Antonio V. Circa, Central Luzon State University
David Teichert-Coddington, Auburn University
Kevin Hopkins, University of Hawaii-Hilo
Kitjar Jayen, Thailand Department of Fisheries
Kamtorn Kaewpaitoon, Asian Institute of Technology
C. Kwei Lin, Asian Institute of Technology
Eduardo A. Lopez, Central Luzon State University
Marco Polo Micheletti, Honduras Ministry of Natural Resources
Pelagie Nyirahabimana, Rwanda National Fish Culture Service
Karen L. Veverica, Auburn University
February, 1996
Department of Agricultural Economics and Rural Sociology
International Center for Aquaculture and Aquatic Environments
Alabama Agricultural Experiment Station
Auburn University
Auburn, Alabama 36849-5406
PHONE: 334-844-5615/FAX 334-844-5639
*Research supported by the United States Agency for International Development through the Pond Dynamics/Aquaculture
Collaborative Research Support Project.
The contents of this document do not necessarily represent an official position or policy of the United States Agency for
International Development (USAID). Also, the mention of trade names or commercial products in this report does not
constitute endorsement or recommendations for use on the part of USAID or the PD/A CRSP.
This research is a component of the Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/A CRSP),
supported by USAID Grant No. DAN-4023-G-00-0031-00 and by contributions from participating institutions. The
CRSP accession number is 1131.
About the Authors
German Cerezo was Research Aide in the International Center for Aquaculture and Aquatic Environments at Auburn
University; Antonio V. Circa is Associate Professor in the Freshwater Aquaculture Center at Central Luzon State University;
Terry R. Hanson is Senior Research Associate in the Department of Agricultural Economics and Rural Sociology at Auburn
University. Kevin Hopkins is Professor of Aquaculture in the College of Agriculture at the University of Hawaii-Hilo and
PD/A CRSP Project Co-Leader for the Philippines; Kitjar Jayen is Deputy Director General of the Department of Fisheries,
Ministry of Agriculture and Cooperatives for the Kingdom of Thailand and PD/A CRSP Project Co-Leader for Thailand;
Kamtorn Kaewpaitoon manages the Aquaculture Short Course Unit and conducts research in the Food and Resource
Engineering Division at the Asian Institute of Technology; C. Kwei Lin is Associate Professor in the Department of Fisheries
at the University of Michigan and PD/A CRSP Project Co-Leader for Thailand; Eduardo A. Lopez is Associate Professor in
the Freshwater Aquaculture Center at Central Luzon State University and PD/A CRSP Project Co-Leader for the Philippines;
Leonard L. Lovshin is Professor of Fisheries and Allied Aquacultures at Auburn University; Joseph J. Molnar is Professor of
Rural Sociology at Auburn University; Pelagie Nyirahabimana was Director of Extension for the Rwanda National Fish
Culture Service; David Teichert-Coddington is Research Fellow in the Department of Fisheries and Allied Aquacultures at
Auburn University and the PD/A CRSP Project Leader in Honduras; Karen Veverica is Research Associate in the Department
of Fisheries and Allied Aquacultures at Auburn University and served as the PD/A CRSP Project Co-Leader in Rwanda.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF
AQUACULTURAL RESEARCH ON TLAPIA:
THE PD/A CRSP IN RWANDA, HONDURAS, THE PHILIPPINES, AND THAILAND
CHAPTER ONE
OVERVIEW
SOCIAL SCIENCE AND THE PD/A CRSP ________
OUTLINE OF THE REPORT _______________
CHAPTER Two
SOCIAL AND ECONOMIC FACTORS IN AQUACULTURAL
DEVELOPMENT
FRAMING CONSTRAINTS FOR FISH CULTURE________
OPERATING STRATEGIES_______________
CONCLUSION______________________
CHAPTER THREE
MODES OF TILAPIA PRODUCTION _____________
TILAPIA PRODUCTION TECHNOLOGY___________
FISH CULTURE SYSTEMS _______________
CHARACTERIZING NATIONAL SYSTEMS__________
LIMITS AND NEW DIRECTIONS FOR FISH CULTURE SYSTEMS__
CHAPTER FOUR
RESEARCH METHODS________________
SAMPLE AND DATA COLLECTION ___________
ANALYSIS
CHAPTER FIVE
PARTIAL NET RETURN ANALYSIS OF PD/A CRSP
EXPERIMENTAL TRIALS__________________
INTRODUCTION ___________________
ECONOMIC ANALYSIS________________
PD/A CRSP NUTRIENT EXPERIMENTS _________
CHAPTER SIX
SURVEY RESULTS: PATTERNS OF TECHNOLOGY UTILIZATION ___
RESPONDENT CHARACTERISTICS ____________
LANDHOLDINCG____________________
FARM ENTERPRISES ________________
POND LOCATION AND WATER SOURCE__________
FISH FEEDING ___________________
FERTILIZATION _____________________
FINGERLINGS _____________________
STOCKING AND GROW-OUT PRACTICES_________
WATER MANAGEMENT _______________
1
2
4
4
4
6
8
9
9
9
10
12
13
13
16
16
16
17
18
24
24
24
25
26
26
27
28
29
29
HARVEST PRACTICES ________________
MARKETING _____________________
MARKETING PROBLEMS _______________
IMPACTS ON HOUSEHOLDS ______________
POND CONFLICTS__________________
PROSPECTS FOR THE POND ______________
TECHNICAL ASSISTANCE________________
CHAPTER SEVEN
SURVEY RESULTS: DIFFERENCES By FARM SIZE________
INTRODUCTION ___________________
FARMER PERCEPTIONS OF TILAPIA CULTURE________
NUTRIENTS AND FERTILIZATION_____________
FINGERLINGS ____________________
PRODUCTION CYCLE CHARACTERISTICS_________
MARKET CONSTRAINTS _______________
RELATIVE PRICES OF FISH ______________
TECHNOLOGICAL CHANGE AND AQUACULTURAL
DEVELOPMENT____________________
CHAPTER EIGHT
THE INSTITUTIONAL NETWORK FOR TILAPIA TECHNOLOGY
IN FOUR PD/A CRSP COUNTRIES___________
INTRODUCTION____________________
RWANDA INSTITUTIONS________________
HONDURAS INSTITUTIONS _______________
PHILIPPINE INSTITUTIONS _______________
THAILAND INSTITUTIONS________________
CHAPTER NINE
CONCLUSION: TILAPIA TECHNOLOGY IN FOUR PD/A
CRSP COUNTRIES ________________
IMPACTS OF THE PD/A CRSP ___________
PD/A CRSP RELATIONSHIPS To GOVERNMENT AND INDUSTRY
TECHNOLOGY TRANSFER ______________
FINANCIAL ANALYSIS ________________
FINGERLING PRODUCTION ______________
REPRISE: IMPACTS OF THE PD/A CRSP_________
REFERENCES
APPENDICES
Information contained herein is available to all persons without regard to race, color, sex, or national origin.
30
31
31
32
33
33
34
35
35
35
40
41
43
43
44
44
45
45
46
48
53
57
60
60
61
62
63
64
65
66
69

SOCIAL,
ECONOMIC, AND
INSTITUTIONAL IMPACTS
OF AQUACULTURAL RESEARCH ON TILAPIA:
THE PD/A CRSP IN RWANDA, HONDURAS,
THE PHILIPPINES, AND THAILAND
CHAPTER ONE
OVERVIEW
The Pond Dynamics/Aquaculture Collab-
orative Research Support Program (PD/A CRSP) is a
global research network organized to generate basic
science that may be used to advance aquacultural
development. One of a family of research programs
funded by the United States Agency for International
Development (USAID), this CRSP focuses on
improving the efficiency of aquaculture systems.
The Pond Dynamics/Aquaculture CRSP began
work in 1982 in Thailand, and subsequently in the
Philippines, Honduras, Rwanda, Indonesia, and
Panama. Research continues today in Thailand, the
Philippines, Honduras, the U.S. and, until recently,
Rwanda. At all the sites, the goal is the same: to identify
constraints to aquaculture production, and to design
responses that are environmentally and culturally
appropriate.
The PD/A CRSP has conducted a Global
Experiment for over ten years. The Global Experiment
has served as an organizing framework for guiding
parallel studies in diverse locales in the tropics.
Researchers have conducted a series of standardized
research trials at each site, establishing baseline data
on physical, chemical, and biological processes as they
relate to fish growth. The research network has focused
on tilapia (Oreochromis niloticus), although some sites
have devoted attention to marine shrimp and other
locally significant species. This report examines the
impact of the network's investigations with tilapia.
Tilapia is an important food fish that has great
potential for providing low-cost protein to consumers,
as well as income and food security to farm families in
rural areas. The fish eats filamentous algae,
zooplankton, and phytoplankton because its ecological
niche is low on the food chain. Algae blooms in ponds
can be fostered by the addition of inorganic fertilizers
as well as manures and other sources of organic
nutrients. Much of the work of the PD/A CRSP has
been directed to specifying optimum ways farmers can
fertilize their ponds to increase fish yields (16).
Tilapia also can be grown using commercial
feeds to supplement or supplant food from natural
productivity. In later years, the PD/A CRSP researchers
endeavored to specify the appropriate circumstances
for providing additional feed to fish to improve yields,
shorten growing periods, or enhance economic returns.
The PD/A CRSP program has identified many
of the needed parameters that apply across diverse
environments. This report establishes how and to what
extent the research findings are reaching institutions
serving farmers in PD/A CRSP countries and whether
they in turn are extending the findings to farmers. The
report develops a profile of aquaculture practices,
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
profitability measures, and producer orientations in
four PD/A CRSP countries. To promote the utilization
of aquaculture technology it is important to know what
types of users are most inclined to make successful and
sustained use of the PD/A CRSP production regime.
There is a need to clarify the correspondence between
the PD/A CRSP paradigm, farmer perspectives, and
actual farming system potentials. It has not been
established whether the assumed inputs are available,
at what cost, and if farmers think that the production
regimes fit their farming systems.
To observe the consequences of PD/A CRSP
technologies, some definition of what has been
developed and made available to farmers is necessary.
There is some variability in approach across the PD/A
CRSP sites due to institutional interests and the level
of aquaculture practice found in each country. This
report treats fertilization and feeding practices as
central aspects of the PD/A CRSP technology program.
The scientific activities of the PD/A CRSP have
been organized under the unifying Global Experiment.
A highly diverse set of investigations specify the
relative effects of various organic inputs, inorganic
2 fertilizers, feeding strategies, species combinations,
water parameters, and other variables on fish
production. It is not unreasonable to expect that the
main impacts of the PD/A CRSP are transmitted to
producers through national institutions, although
nongovernmental agencies and private sector firms also
are intermediaries for PD/A CRSP research results. The
PD/A CRSP should have some connections to the
general level of pond-based aquaculture practice
because this has been the general focus of the PD/A
CRSP across the various sites.
It is also important to understand the
interactions among family, farming system, and
community as they together shape the choice and
continued utilization of technology. Clearly, economic
or financial profitability is one signal criterion used by
farmers to adopt and continue fish culture (32,37). The
interaction between other farm enterprises and
household activities also shapes these choices. We
remain centrally interested, however, in feeding and
fertilization practices as farm-level outcomes or
dependent variables to be explained by the PD/A CRSP
intervention. The connection between research
strategy and finding in relation to actual practice is
the central focus of the study. The report provides
information that profiles the major points of
convergence in the production and marketing of tilapia
across the four PD/A CRSP sites.
Important questions pertain to the technologies
and production regimes emerging from research that
can actually be implemented on farms in the project
countries (6). Much of the baseline data commonly
found in other agricultural sciences has been lacking
in aquaculture (60,68).
SOCIAL SCIENCE AND THE PD/A CRSP
Understanding the circumstances and
motivations that shape farm operator decision
processes will be a significant step toward designing
and maintaining a technology transfer effort that will
be sustainable and effective (17,43). There are important
commonalities among farmers across the PD/A CRSP
sites; there are also important differences in price,
market organization, ecology, farming system, and
social matrix. Sustainability is a common theme across
these diverse disciplinary subject-matter areas.
Sustainability. Sustainability is the ultimate
measure of success for a development intervention (43).
If people continue to grow fish while being emulated
by their neighbors and residents of other communities,
aquaculture will have furthered the cause of
development and food security (45). Sustainability has
environmental, social, and institutional dimensions.
Aquaculture is environmentally sustainable
when the water it uses and the pollution it generates
do not exceed the carrying capacity of the locale where
fish farming is practiced (8). Pullin argues that smaller-
scale and less-intensive aquaculture operations,
especially those integrated with agriculture, are less
likely to pose environmental 
problems (53).
Aquaculture is socially sustainable when
neither its benefits nor its costs are concentrated in one
segment of the population. Ideally, fish farming should
engender equitable participation in its benefits across
a wide spectrum of socioeconomic segments of the
community. In reality, not all farmers are inclined or
able to build ponds. Other constraints limit
participation in aquaculture to those able to make
productive use of their time and resources in the
activity. Nevertheless, fish farming can augment the
array of locally-based opportunities for food
production and income generation, and can benefit
many residents in different ways.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
The social costs of aquaculture are often
connected to conflicts linked to the loss of access to
resources. Fish farming may accelerate the enclosure
of formerly open-access lands or coastal waters.
Private fish ponds may divert water from formerly
shared uses; effluent from ponds may alter the quality
of water for other users. When the expansion of
aquaculture limits opportunities or livelihoods for other
community residents, social sustainability may be
questioned. Regulation of effluent discharge,
promulgating access rules for coastal areas, and
promoting the orderly allocation of water resources are
important roles for the state in moderating the market
forces driving the expansion of aquaculture (4).
Conversion of mangrove swamp and other
coastal area into ponds is a major issue for shrimp
aquaculture (4). The new farms often restrict access to
the resource base that would otherwise support a
variety of livelihoods associated with small-scale
fishing and aquaculture. Similarly, Ahmed et al.
conclude that the benefits of improved aquaculture
technology will accrue mainly to the owners of small
waterbodies whose present socioeconomic
circumstances are better than the rest of the rural
Bangladesh population (1). They observe that it may
be necessary to promote low-cost technologies for
aquaculture as well as to provide institutional and
policy support to enable poor and landless people to
get access to waterbodies and adopt aquaculture.
Aquaculture is institutionally sustainable when
the services and subsidies required to build and
continue the industry do not exceed the fiscal and
organizational capacity of the state. Ultimately,
subsidies should cease and state services should
become minimally necessary to aquaculture's viability
as a widely-practiced farm enterprise. It should be
noted that the primary influence of PD/A CRSP
activities is exerted through the institutional context of
the research sites and the network of students,
extensionists, technicians, and host country scientists
that collaborate with PD/A CRSP scientists. This report
documents the nature and extent of these institutional
effects of the research program.
Livelihood activities such as aquaculture are
embedded in a structure of social relations; therefore,
for the theory and practice of induced development,
defining the levels of such embeddedness becomes the
critical task. Individuals make decisions in the context
of family, household, and village social relations
(46,48,54). These considerations shape responses to
basic economic incentives and create other motivations
for selecting activities and approaches that are often
more powerful than price signals. They determine
which price mechanisms operate and under what
circumstances (23).
Social Knowledge. The systematic use of social
knowledge, as a complement to economic and technical
knowledge, is indispensable for "putting people first"
in development interventions (12). For the PD/A CRSP,
farm-level effects have increased in centrality as basic
scientific issues have been clarified and the political-
administrative paradigm within USAID has shifted
toward a concern for the more immediate consequences
of development funding.
The work to be done by social scientists that
furthers the objectives of the PD/A CRSP and of
development should differ substantively in perspective
to what is habitual in disciplinary practice (13,41). The
canons of method and statistical interpretation remain
fundamental ties to sociology, but the focus and level
of discourse must be different.
Although the PD/A CRSP is not a village-level
development effort, social science research must
endeavor to attune the other specialists - technical and
economic - to the demands of putting people first.
Only in the late state of the PD/A CRSP has social
science become recognized as an explicit complement
to the research program. As such the work presented
here can only document some of the effects and issues
that might have been more appropriately considered
as an integral part of the Global Experiment.
The PD/A CRSP must be understood as an
institutional innovation, a means for fomenting
technical change in national aquaculture industries.
Although not organized to deliver technology on the
village level, it is a mechanism for improving the lot of
family farms and the villages they encompass, albeit
indirectly, through each nation's institutional network
for aquacultural development. Consequently, much of
the direct impact of the PD/A CRSP is focused on the
organizations and institutions that house PD/A CRSP
researchers, their laboratories, and field facilities. The
changes instilled by a science and technology project
such as the PD/A CRSP are largely felt at the
institutional level where individuals are training,
procedures put in place, and facilities are planned with
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
expatriate technical assistance. This set of processes will
be examined in detail in a subsequent PD/A CRSP
social science study.
Impacts. In terms of changes in national
aquaculture industries, the impacts of the PD/A CRSP
are manifold. A chapter in this report details the
institutional context of each nation and portrays the
role of the PD/A CRSP in the nation's technical-
knowledge system for aquacultural development (55).
Many of the advances that take place in an aquaculture
industry are facilitated by the formal and informal
consulting of PD/A CRSP scientists with private sector
firms that grow fish or manufacture and sell inputs to
farmers. The researchers' presentations at meetings,
visits to laboratories and facilities, and personal
communications with industry scientists and managers
remain a continuing nexus of impact for the PD/A
CRSP.
At the individual farm and village level, we
examine the survey reports of fish farmers as to the
role that tilapia culture plays in their farms and in their
lives. The context or surrounding environment may
enhance or inhibit the pursuit of fish farming. Where
4 many farmers are producing fish and it is a commonly
traded item in the marketplace - such as in Thailand
- fish culture is easily adopted. Inputs are readily
available, there is often competition among input
suppliers, and providers of specialized services such
as fingerling delivery or custom harvesting are
available.
Following the sociological dictum "situations
defined as real are real in their consequences" we profile
fish farmer perceptions of the process of growing
tilapia, harvesting the crop, and marketing the fish. We
endeavor to specify basic dimensions of farmer
perceptions of the effects of the tilapia enterprise on
the household. Farmer perspectives on production
problems, institutional functioning, and government
services also are important forces shaping the
acceptability and utilization of PD/A CRSP technology
(11).
OUTLINE OF THE REPORT
The report provides a comparative perspective
on the social and economic dimensions that interact
with biological variables in the conduct of fish culture
in the various locales. The report also summarizes major
dimensions of variability in the financial incentives
presented to producers across the sites.
The objectives of the study are three: first, to
profile the farming system, fish production practices,
and household circumstances of tilapia farmers in four
PD/A CRSP countries; second, to examine the
economic incentives and constraints confronting tilapia
producers in terms of market signals, input costs, and
the relative profitability of various experiment-based
tilapia production strategies; and third, to provide an
overview of the institutional context of the PD/A CRSP
in each country's program of tilapia technology
development and transfer.
CHAPTER Two
SOCIAL AND ECONOMIC FACTORS IN
AQUACULTURAL DEVELOPMENT
This chapter presents a framework for
considering socioeconomic factors affecting the
implementation and sustained pursuit of pond
aquaculture. It integrates, compares, and synthesizes
what is known about the conditions promoting
successful adoption and sustained use of aquaculture
technology. It begins with a brief overview of tilapia
production technology and production strategies. A
typology of producer orientations is developed to
anticipate the data analysis that follows in subsequent
chapters.
FRAMING CONSTRAINTS FOR FISH CULTURE
Framing constraints are the conditions or
circumstances that determine the possibilities and
incentives for tilapia production in a particular locale.
Material constraints refer to the physical and
environmental factors that determine whether the
raising of fish is materially possible or feasible.
Socioeconomic factors operate after it has been shown
that it is feasible to grow fish in a locale; they determine
whether the raising of fish is desirable or acceptable as
a human activity (6).
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Material Constraints. Soils affect tilapia culture
because they determine the water holding capacity of
ponds and the productivity of the aquatic environment.
Soil properties are directly related to the nutrients in
pond water. Acidity, hardness, and other water quality
properties have their origins in the soil environment.
Water from runoff, groundwater, streams, or
impoundments is necessary for fish culture. Individual
farms vary in the amount of water they can access and
retain. The annual hydrologic regime is a primary factor
shaping fish culture.
Water temperature, and various other water
quality parameters such as salinity and acidity also
condition the possibilities of fish culture in a given
locale. Tilapia have an optimal temperature range for
viability and reproduction; in Rwanda this constraint
is a central consideration for researchers and producers.
In warmer waters, other parameters may be limiting
factors.
Socioeconomic Constraints. Socioeconomic
framing constraints include markets, infrastructure,
community milieu, household dynamics, and producer
orientations. The educational level of producers directly
shapes their ability to search for and utilize new
technology and to participate in market processes.
Lightfoot outlines an extension strategy for
understanding the complex connections between
households, resource systems, and the larger milieu
which shape the possibilities for rural livelihoods (40).
Beyond the pond environment, market
incentives, consumer preferences, input availability,
and the financial condition of farm households each
affects the production strategy appropriate to a locale
and a particular set of farmers. Cultural acceptability
of fish in general or a particular species affect the
prospects for selling or consuming fish once they are
produced. Prices affect the incentives for producing fish
and the extent to which all segments of a community
would be able to purchase fish if availability were
increased. The ability to sell or barter fish for cash or
other items is a basic consideration determining
whether fish will be selected as a farm enterprise and
whether subsequent crops will be grown.
To understand the type of technology that
tilapia farmers employ and the production strategy they
choose, it is important to understand the role of the
aquacultural enterprise in the farm household, the
infrastructure for marketing and distribution, and the
place of tilapia in the dietary regime of the population.
Infrastructure refers to the institutional and
organizational mechanisms that allow the conduct of
fish culture and the development of an industry.
Fingerling supply, disease control services, and feed
supply are key components of the infrastructure that
supports the development of an aquaculture industry.
Research and extension advice also are significant
support services that enhance the long term viability
of aquaculture. Credit availability and some level of
monetary stability also are part of the conditions
favoring aquacultural development.
Tendler's study of the institutional history of
several small successes in agricultural extension and
research portrayed a complex milieu of public agencies,
local elites, and strong centralized public sector actors
(65). She found that demand-side factors - particularly
the presence of organized user groups or representative
agencies - played important roles in driving research
and extension to do better.
The community milieu for fish culture refers to
the normative structure of villages with respect to
innovations in general and fish culture in particular.
The kind of support or criticism farmers receive from
their peers and neighbors is one force encouraging or
discouraging the adoption of fish culture as a farm
enterprise and its continued pursuit. The nature and
extent of preexisting internal divisions within a
community - and whether aquaculture creates or
exacerbates these divisions - can shape the course of
fish farming in the locale. Another aspect of the
community milieu for fish culture is the level of human
predation or the theft of fish and the extent to which
such theft is tolerated or supported by community
norms(51).
Land tenure and agrarian structure can be broadly
defined as the nature and distribution of rights and
access to land and water resources (56). Land tenure
arrangements shape the incentives and risks for farmers
deciding whether to build ponds (15). An important
influence on technology adoption, economies of size
in access to capital and output markets can bias
aquacultural development toward larger, wealthier
farms. Small farm sizes or excessive fragmentation of
land holdings may constrain adoption of certain
"lumpy" inputs such as pumps or tractors. Uncertainty
5
SOCIAL, ECONOMIC, 
AND INSTITUTIONAL 
IMPACTS OF AQUACULTURAL 
RESEARCH ON 
TILAPIA
about land title can discourage investment in pond
construction and other commitments necessary for fish
farming.
Harrison finds that one of the principal
constraints faced by nonadopters of aquaculture in
Zambia was security of land tenure, a constraint felt
most forcefully by women (30). Rothe and his
colleagues conclude that tenure security is necessary,
but not sufficient for the adoption of productivity-
enhancing technology in agriculture (56). As long as
constraints on access to input and output markets limit
incentives to innovate and invest, tenure security itself
does not represent a binding constraint on technology
adoption. Because pond construction represents direct
capital investment in the land, tenure security may be
a larger factor in farmer decisions about this step than
it is in decisions about other kinds of productivity
enhancing technology.
Household dynamics includes a variety of issues
related to decision-making, family roles, the availability
of labor, and the set of issues associated with gender.
Access to labor for pond construction was a primary
barrier to participation in aquaculture for women in
6 Zambia (30). Women were consistently more likely to
cite role conflicts or hardships associated with fish
culture as an addition to their repertoire of activities
(44).
We consider the impacts of a new enterprise
on women, the effects of the fish pond on other
activities, the disposition of harvests, harvest proceeds,
and post-harvest use of fish. Responsibilities and
burdens of feeding, monitoring, harvesting, and
preparing the fish may not coincide with the nutrition,
cash, and other benefits accruing to fish harvests.
Producer orientations represent
the perceptions and attitudes of tilapia
farmers and others who make decisions
about whether and how tilapia will be
grown by a household. The way farmers
define situations dictates the decisions
they make. Molnar et al. conclude that Level
Rwanda farmers undertake fish culture of
largely as a diversification strategy (44). Investmen
Many prefer to accept smaller, more
reliable yields that offer cash and food . .
security with lower levels of risk and Figure 2.1. O
effort. ... _.,=.
Producer education and training includes the
ability to read, write, and calculate. Less intensive
methods of aquaculture can be conducted by non-
literate farmers; when fish farming becomes more
intensive and market-oriented these skills become
increasingly important. The level of education in a
population of fish farmers determines the kinds of
communication strategies that are necessary to convey
technical information for advancing the practice of fish
culture (2,19).
OPERATING STRATEGIES
The operating strategy undertaken by tilapia
operators is the approach farmers take to raising fish;
it reflects the effort, technology, attention, and resources
devoted to the enterprise. Tilapia culture can be
understood in terms of the household's level of
investment and the level of dependence on the fish
culture enterprise. The following typology uses the two
basic dimensions relating to investment and
dependence on the tilapia enterprise to portray the
operating orientations of tilapia farms. It is used here
to summarize the major dimensions of variability in
the ways tilapia is grown across national settings. In
particular, we are interested in explaining the pattern
of technology choices and the trajectory of technology
and information needs associated with various
operating strategies.
Figure 2.1 shows level of dependence on the
aquaculture enterprise and amount of investment in it
as determining operating strategy. The pattern of
technology choices that a farm operator undertakes can
be understood as a function of dependence on the
outcomes and investment in the means of production
- facilities and equipment - for growing tilapia. This
typology will be used to understand the kind of tilapia
Level of Enterprise Dependence
Low Medium High
Low Peripheral Marginal Subsistence
Medium Residual Complement Focused
t
High Venture Diversified Specialized
)erating strategy as a function of household dependence on and
the enterprise.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
production technology employed in various locales and
to anticipate trajectories of development if certain
barriers were overcome.
Dependence refers to the relative importance
of the tilapia-raising activity in contrast to other
production activities and the overall wealth of the
household. It is reflected in the relative share of family
and personal resources devoted to the aquaculture
enterprise. Investment refers to the amount of capital
and other financial resources deployed in the fish
culture operation. Cross-tabulating these two
dimensions summarizes the major clusters of farm
types characterizing the aquaculture industry in general
and tilapia in particular. The central point of
comparison is the orientation of the farm operator
toward technology adoption.
With one exception to be explained in a
subsequent section, we consider intensive production
to entail high levels of investment; all other categories
are considered to pursue semi-intensive or less
aggressive approaches to fish culture. The typology is
intended to simplify and summarize a great deal of
variability. We acknowledge the existence of counter
examples and other logical possibilities, but the
classification does summarize a great deal of variability
and provides ready insights into the strategies or
farming styles undertaken by fish farmers.
Peripheral approaches to fish culture are those
where the relative level of investment is low and the
level of dependence on fish culture for food or income
is low. That is, this segment of the population pursues
fish culture as a hobby, pastime, or curiosity. For
example, one Dutch project in Jamaica worked with
small private backyard ponds often containing less
than 50 fish (51). The activity was often undertaken
by young people. The nutrition and income benefits
of this type of aquaculture are limited at best,
although there may be other significant consequences
for individual and community development. In
Honduras, a retirement-age fruit grower con-structed
a series of small concrete tanks to grow tilapia for
household consumption, feeding them citrus rinds
and other available inputs (47).
Residual tilapia operations utilize tilapia
primarily as a means to capture secondary benefits from
a large-scale primary activity such as poultry
production or food processing. Moderate investment
in tilapia production reflects the financial standing of
the operator, but low dependence reflects the small size
of the tilapia revenue compared to other income
sources. The wastes or byproducts of the primary
activity are used as an input to aquaculture. Where the
level of investment is moderate and enterprise
dependence is low, aquaculture will be a residual or
secondary activity pursued centrally for the income
from the fish as a byproduct of another activity.
When tilapia production is a residual
enterprise, few other inputs are applied as the fish are
mainly intended to capture unused resources from the
primary activity. Such operators are typically interested
in producing a fish commodity with undifferentiated
quality. Wealthier poultry farmers in Thailand primarily
fit this category of the typology. For this type of farm,
tilapia is a fortunate byproduct of another line of
activity.
Venture farming of tilapia represents fish
culture undertaken by nonfarm or farm interests
centrally motivated by potential high rates of return or
adoption rents associated with a booming business.
Such operators are not dependent on the fish enterprise
to maintain their livelihoods; instead they are likely to
employ a hired manager to oversee day-to-day
operations. One such operation observed in Thailand
was founded by a construction company owner on the
advice of some of his investment-minded friends (44).
Located literally in the shadow of one of the largest
poultry-producing complexes in Thailand, the farm
utilized a semi-intensive approach to producing large 7
quantities of fish for the open market. Tilapia-
producing subsidiaries of large feed corporations also
would be included in this category.
Marginal farmers are somewhat dependent on
the income from tilapia production but operate at a low
level of investment. They are likely to use less
technology and low intensities of operation. Often
constructed as a speculative investment by a local
business person or professional, many of the moderate-
sized and small tilapia farms in Honduras and some in
Rwanda may be thought to be marginal operations.
They are moderately dependent but minimally invested
in the activity; thus fish culture is most vulnerable to
competing uses of their land, labor, and attention (47).
Farming of tilapia can be a complement to other
farm activities. As such, it represents moderate
investment and moderate dependence on the
enterprise. Complement strategies differ from residual
strategies in the amount of effort applied to tilapia;
tilapia receive more management attention and the
enterprise is more central to the overall farming system.
In this manner, tilapia rounds out the cycle of input
use and resource availability on the farm. It is a
significant proportion of family income. Family-scale
tilapia farms in Thailand most fully represent this
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
category. Such farmers are likely to attend more directly
to the technology and management of their fish because
of the greater meaning the harvest has for household
well-being; they are more dependent on the tilapia
income than residual farmers.
As a complement to the overall farm strategy,
tilapia are grown primarily for ready cash flow and its
low labor requirements. Family-scale farms featuring
integrated operations producing pigs, ducks, or rabbits
centrally exemplify this category (52). Small and
moderate-scale farms in Thailand often culture tilapia
in ponds under their chicken houses. Utilizing the
chicken waste and feed not consumed by the chickens,
farmers grow tilapia to capture the complementary
benefits associated with the poultry enterprise.
Complement operators may be more receptive to
improvements in methods or procedures of tilapia
production than in technologies that require high levels
of investment or significantly increase operating costs.
Diversified operators have moderate
dependence on tilapia growing, but have a high
investment in the enterprise. Centrally, these are
moderate-size farms that pursue fish culture as a
significant part of the activity mix in their farm
S business. Such operators have a serious 
interest in new
technology and management strategies that reduce risk
and optimize return on investment. One dairy farmer
in Jamaica was shifting his attention and investment
from milk production to include semi-intensive culture
of tilapia as a diversification strategy (51).
Subsistence operators have a high dependence
on the income and food supply represented by their
ponds but have low investment in the enterprise. They
may be centrally concerned with the risk reduction
represented by the presence of the farm pond. They
may be most interested in low-cost, no-cost, no-cash
strategies for enhancing the amount and quality of fish
produced from their lands. They are likely to be
reluctant to implement strategies requiring regular use
of purchased inputs. Fish farming in Rwanda may be
described as a poverty-reduction strategy for
households with little cash, little land, and high risks
of crop failure and other adversity.
Focused operators have a high level of
dependence on tilapia culture for their livelihoods, but
only a moderate level of investment. They may be most
interested in ways of optimizing the use of existing
inputs or utilizing technologies that have moderate
levels of financial risk. Individuals with fish farming
as their sole activity are included in this category; many
may have off-farm income from their own or a spouses
employment.
A small farm operator with a great deal of
expertise could undertake a focused operating strategy
that involves intensive production of tilapia. Such an
operation would require a high level of managerial
ability. Intensively feeding a dense population of fish,
possibly by exploiting a spring or other source of
flowing water, an individual could utilize his own and
family labor to sustain a household through this form
of livelihood. Cage culture may offer particular
advantages to a focused small farm operator. We
observed no such operations, but undoubtedly they
exist.
Specialized tilapia farmers have a high level of
investment and a high level of dependence on tilapia
production. By definition, this category excludes nearly
all small-scale or subsistence operations because of the
investment requirements. Most United States tilapia
producers fall into this category. They are highly
motivated to seek information and technology to
maximize the benefits of their choices and interests in
tilapia. Most PD/A CRSP countries have only a few
specialized operators who typically produce for export
or specialized internal markets. Some also maintain
processing facilities.
Large investor-backed farms engaging
primarily in tilapia production for export or specialized
markets are the central occupants of this category of
the typology. These operators often produce their own
fingerlings and frequently seek to supply surrounding
farms with excess seed production. Such farms typically
have high levels of investment in pumps, facilities, and
personnel. They may seek to contract production to
neighboring family-owned farms to ensure supply for
processing facilities. Such firms may have internal
experts and regular contacts with private consultants
to manage the level and kind of technology used in
reproduction and grow-out.
CONCLUSION
This typology of tilapia farming can be used to
understand modes of adaptation and response to
changing technology, input costs, and other
circumstances shaping the conduct of aquaculture. PD!
A CRSP technologies primarily have to do with
fertilization and the management of water quality
parameters. As such, PD/A CRSP has focused on
techniques and approaches most appropriate to low
and medium levels of capital investment at all ranges
of dependence.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
CHAPTER THREE
MODES OF TILAPIA PRODUCTION
This chapter identifies basic dimensions of
tilapia production technologies with emphasis on
Thailand, Honduras, the Philippines, and Rwanda. The
notion of intensity of production is developed and the
nature of the production system predominant in each
country is examined in terms of the intensity
classification. Although this chapter provides a context
for interpreting the survey results that follow in a
subsequent chapter, readers already familiar with
tilapia production technology may simply turn to the
findings.
TILAPIA PRODUCTION TECHNOLOGY
Tilapia is cultured in a variety of modes around
the world. The kind of technology used is closely linked
to the socioeconomic circumstances of the farmer, as
the intensity of production often corresponds to the
amount of capital investment. Although we focus on
inland farming and freshwater tilapia production, use
of brackish water to grow tilapia is increasingly
important in coastal areas. Brackish water production
of tilapia is increasingly important as an alternative or
rotational crop for shrimp production where this
organism is suffering declining yields due to disease
or other problems.
Production of tilapia in freshwater ponds is the
central focus of the PD/A CRSP research program.
Nevertheless, tilapia also can be grown in cages or pens.
Suspended from floats or docks in a body of water,
cages may be simple wicker or wooden containers or
may be more sophisticated and expensive wire mesh
boxes used to confine fish. Pens utilize nets to fence
the cultured fish in an enclosed area. Pens are fenced
areas in lake, rivers, or ponds where fish are confined
for feeding and harvest. Most farm operations,
however, utilize open-water ponds.
Cage and pen culture represents an intensive
production strategy, typically involving the provision
of high quality feed to dense populations of growing
fish. Water quality becomes increasingly important as
a framing constraint and farm management concern
in intensive production systems. In addition, stocking
density, type of feed, and whether or not fertilization
is used remain additional dimensions shaping the type
of tilapia culture undertaken. There are also variations
in the species or strain of tilapia employed, whether or
not mixed or monosex populations are cultured, and
the size of the fingerlings that are stocked.
In most systems, the tilapia fingerlings
consume nutrients from algae and plankton growth.
The algae bloom is augmented by some form of
fertilization. In some cases, tilapia also receive a
commercial ration; in the most intensive systems the
commercial feed is the only nutrient source. The major
possibilities for the culture of tilapia are centrally
determined by the kind of water and type of enclosure
used to house the fish. PD/A CRSP research has
focused on fish grown in open ponds, and not on cage
or pen culture.
FISH CULTURE SYSTEMS
Fish culture is often classified by the level or
amount of human control over the culture system and
the quantity and quality of feeds and fertilizers placed
in the system (16). A classification of intensity of control,
investment, and risk in fish culture is developed in this
section of the report. This classification can be used to
understand variability in the practice of fish culture
within a nation and between nations. Three levels of
fish culture intensity can be identified as follows. The
combination of feeding and fertilization can be used to
differentiate one major set of divisions in tilapia
production strategies. Figure 3.1 shows four major
types of production strategies that bear on the
development and use of PD/A CRSP technologies.
Each type is explained in the subsequent discussion.
Extensive. Systems relying solely on natural
productivity to provide nutrients for fish stocked at a
low density are termed extensive. No nutrients are
provided to stimulate, supplement or replace natural
foods. Recreational fish ponds are often managed in
this manner. In addition, there often is incomplete
control over species composition and the number and
size of individual fish. Lime may be used to foster algae
blooms, but no feed or other nutrients are added. The
operator exerts some control over the quantity of water
Input Feed No Feed
Fertilizer Semi-Intensive Augment ative
No Fertilizer Intensive Extensive
Figure 3.1. Culture strategies combining feed and fertilizer.
9
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
supply, but no control over water quality. Incomplete
drainage and harvest typically are normal practices. The
PD/A CRSP has used extensive systems or natural
productivity as a baseline condition for comparing the
relative efficacy of various feeding and fertilization
regimes.
Augmentative. When additional nutrients are
supplied to the pond to enhance natural productivity,
the producer is undertaking an augmentative strategy
Fertilization supplements naturally occurring nutrients,
enhancing the output of algae and other organisms
supported by photosynthesis. The availability of
microorganisms for the fish to eat is thus increased, and
in some cases manures and other materials provided
to the pond may be directly consumed by tilapia. The
PD/A CRSP research findings that apply most directly
to small-scale and moderate-size farms are
augmentative combinations of animal manures, locally
available byproducts (slaughter waste, food processing
wastes, etc), or other on-farm organic inputs - such as
kitchen waste - that are often diverse and irregularly
available.
Commercial fertilizers allow higher stocking
10 densities but also represent an out-of-pocket cost, a
serious impediment for many developing country
farmers. Augmentative strategies most often employ
manures and other available farm inputs as nutrient
sources for algae blooms. Tilapia also directly consume
some of the detritus and other organic matter found in
manures and other inputs. One limit to stocking density
and the exclusive use of organic materials is the level
of biological oxygen demand associated with the decay
of these materials. Too much material for a given
volume of water can suffocate the live animals,
particularly at later growth stages.
Semi-Intensive. Most family farms in the
countries examined in this report employ semi-intensive
strategies; that is, operators fertilize their ponds and
they also feed their fish. Pond water is fertilized with
fresh vegetation, chemical fertilizers and/or manures
to stimulate the growth of natural food organisms. Fish
typically are fed a poor quality feed that supplements
the natural pond foods. The combination of fertilization
and feeding is the central attribute of semi-intensive
strategies. Feeding is helpful at the fingerling stage
supplementing zooplankton and phytoplankton, the
normal food for the young fish. Feeding also is helpful
at the later stages of fish growth when the natural
productivity of the pond may not be sufficient to allow
the crop of larger fish to grow at an optimal rate.
Specifying optimal paths of fertilization and feeding is
a central aspect of the PD/A Global Experiment.
In semi-intensive strategies, the operator exerts
complete control over the quantity of water supply, but
little or no control of water quality; drainage and
harvest are usually complete. The operator has nearly
complete control over species composition, number,
and size within species.
Intensive. Modes of production characterized
as intensive encompass industrial-scale tilapia
operations. There is complete control over species
composition, number, and size within species ensuring
homogenous individuals at harvest. Fish are given a
feed that supplies complete nutrition, usually in the
form of pellets. Fertilizer is not used because excessive
nutrients fuel algae blooms that compete for oxygen
and asphyxiate the fish.
The operator exerts complete control over the
quantity of water supply. Clear, clean water is vital to
the survival of densely-stocked masses of fish that
obtain all nutrition from commercially-prepared feeds.
Filtration, steady replacement or partial water
exchange, aeration, or a combination of these systems
are used to maintain water quality; drainage and
harvest are complete.
This type of system is centrally used by large-
scale producers, although a small-scale farmer with a
unique set of resources and capabilities could undertake
intensive production. We observed a Honduran farm
situated on a small plot of land with a high-quality
water source. A graduate of a PD/A CRSP training
program, he cultured red and black tilapia strains in a
flow-through water system to produce fingerlings for
surrounding farms, moderate-size fish for direct
marketing, and larger fish featured in the family
roadside restaurant (47).
CHARACTERIZING NATIONAL SYSTEMS
The above classification will be used to define
tilapia culture systems in Thailand, the Philippines,
Honduras and Rwanda.
Rwanda. Species: Oreochromis niloticus.
System: Small producers (subsistence farmers)
culture mixed-sex tilapia. Most fish harvested are
under 200 grams. Fingerlings are produced by
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
government hatcheries, but farmers supply most
fingerlings to each other. Tilapia are raised in small
ponds (100 to 1,000 square meters) and most farmers
have a single pond. No monosex male culture is
practiced outside government stations.
Culture: Annual harvest is estimated to be 21 metric
tons. Farmers undertake augmentative strategies
using manure or compost, but do not normally
purchase commercial feeds due to their limited
availability. Most farmers limit their efforts to placing
vegetation in their ponds; a subset will collect and
place manures in their pond. Chemical fertilizers are
scarce and expensive.
Supplemental feeding is scarce and restricted to a
few wealthy individuals or institutions. No intensive
culture is practiced because prepared feeds are not
available. Imported netting, woven twine, or baskets
are used to capture fish.
Yields: Tilapia yields are low because of the lack of
nutrient inputs and the cool climate. Most fish
culture is located at 1,400 to 2,000 m elevation and
the cool water temperatures at this altitude slow
tilapia growth. Yearly yields range from 200 kg/ha
in poorly managed ponds to 5,000 kg/ha in well
managed ponds.
Markets: Tilapia are consumed at home, sold fresh
on the pond bank, or made available in local markets.
No tilapia are exported.
Honduras. Species: Oreochromis niloticus and hybrid red
tilapia are commonly chosen for culture.
System: Small producers (subsistence farmers)
culture mixed-sex tilapia. Some Honduran farmers
polyculture their mixed-sex tilapia with a predator
to control unwanted tilapia offspring.
Tilapia culture is less than 20-years-old in Honduras.
Tilapia are raised in earthen ponds. Most farms are
small but several large farms (20 to 40 hectares) exist.
Conditions are favorable because land and water are
abundant and relatively inexpensive. Modern tilapia
culture technologies have been rapidly disseminated
among farmers.
Presently, more male tilapia are cultured than mixed-
sex tilapia. Male tilapia are produced by
hybridization and sex reversal. Most tilapia
fingerling production comes from government
hatcheries. However, the private sector is growing
rapidly and will soon be able to supply most tilapia
fingerling needs.
Culture: Annual harvest is estimated to be 65 metric
tons. Small farms use semi-intensive feeding and
fertilization while larger, wealthier farmers are using
intensive approaches. Most use chemical fertilizers,
manures and agricultural by-products to raise their
fish. Fish ponds are rarely integrated with animal
husbandry activities. Honduras has only a short
history of fish culture. Ponds are uncommon in the
countryside and fish culture is not widely practiced.
Farmers are not skilled in the art of fish culture.
Pelleted fish feeds are available but they are
expensive and the quality is suspect. Nets are
imported, expensive and not widely available.
Yields: Tilapia yields vary greatly depending on the
level of culture employed. Yields can range from 200
to 300 kg/ha/yr in poorly managed family ponds
to about 6,000 kg/ha/yr in heavily manured and/
or fed ponds. Aeration is still not practiced in
Honduras and except for limited water exchange,
dissolved oxygen limits the amount of fish
harvested.
Markets: Tilapia culture is in its infancy and yearly
production is low. Most fish are consumed in the
household, sold to restaurants, or sold fresh in local
markets. The local market for tilapia is poorly
developed; prices and profits tend to be low. Two
large farms in the San Pedro region export tilapia to
the U. S. and other markets.
Philippines. Species: Both Oreochromis niloticus and
Oreochromis mossambicus or their hybrids are widely
cultured in fresh and brackish water. The red tilapia
hybrid is also cultured.
Culture: Annual harvest is estimated to be 91,200
metric tons. The majority of tilapia culture is mixed-
sex production of fish less than 200 grams. Small
tilapia are widely accepted in the Philippines. The
production of sex-reversed male tilapia is common
and will grow rapidly as hatcheries are able to supply
more male fingerlings to producers. Tilapia are
raised in earthen ponds, cages and rice fields.
The Philippines probably grows more tilapia in cages
than any other country in the world. Earthen ponds
11
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
are typically small, and water area per farm less than
0.5 hectare. However, thousands of hectares of
brackish water ponds formerly used to culture
milkfish are becoming available as tilapia culture
becomes more lucrative. Tilapia are commonly
grown in monoculture or stocked with a predator
species to check extraneous reproduction in the fish
crop.
Semi-intensive feeding and fertilization
predominate. Few farmers intensively culture tilapia,
but intensive culture will grow rapidly as export
markets are captured. The Philippines also has a long
history of fish culture and it is an integral part of
rural farming activities. Many farmers are skilled in
growing fish. Tilapia are commonly raised with
chemical fertilizers, fresh manure (integrated with
animal husbandry) and supplemental feeds (rice
bran and household wastes). Complete pelleted
feeds and nets are available in the Philippines.
Yields: Tilapia yields vary greatly depending on the
level of culture employed. Yields can range from 200
to 300 kg/ha/yr in rice fields and poorly managed
family ponds to over 10,000 kg/ha/yr in heavily
12 manured 
and/or fed ponds.
Markets: The Philippines may be the largest producer
of cultured tilapia in the world and is certainly one
of the top two. Most of the tilapia is consumed
domestically. Tilapia are cultured to improve family
nutrition and economic gain. In addition to the
strong internal demand for tilapia, exports are
certain to play an important role in the future of
Philippine tilapia farming. Taxes, land prices, and
other production costs, however, make the
Philippines a high-cost producer relative to other
exporting countries.
Thailand. Species: Predominantly Oreochromis niloticus,
but both Oreochromis mossambicus and lesser
amounts of the red hybrid tilapia are cultured. Tilapia
are commonly raised together with other species of
fish (polyculture). Tilapia monoculture is common
only in the last few years.
System: The vast majority of tilapia culture in
Thailand is still mixed-sex production of fish less
than 300 grams. Fish are raised in earthen ponds and
rice fields. Ponds range in size from 100 m2 to about
2 hectares. Tilapia farms are small with most farmers
having less than 1 hectare of water. A few large tilapia
farms exist but even these farms normally have less
than 10 hectare of water.
Recently, the production of male tilapia fingerlings
by hormone sex reversal has gained popularity
among wealthier farmers. Mixed-sex and male
tilapia fingerlings are produced by the private sector.
Culture of male fish has resulted in the harvest of
400 to 600 gram tilapia.
Culture: Annual harvest is estimated to be 60,000
metric tons. Semi-intensive feeding and fertilization
predominate. Some larger farms culturing male fish
are intensively farmed. In the poorer rural areas
semi-intensive approaches are used. Thailand has a
long history of fish culture and it is an accepted
farming activity. Many farmers have a working
knowledge of fish culture. Most farmers with proper
soil type and water will have a fish pond or raise
fish in their rice fields.
Tilapia are commonly raised with chemical
fertilizers, fresh manure (integrated with animal
husbandry) and supplemental feeds (rice bran and
household wastes). Feed mills are producing
complete pelleted feeds but their use is not widely
accepted by tilapia growers. Nets are widely
available.
Yields: Tilapia yields vary greatly depending on the
level of culture employed. Yields can range from 200
to 300 kg/ha/yr in rice fields and poorly managed
family ponds to over 10,000 kg/ha/yr in heavily
manured and/or fed ponds.
Markets: Thailand produces a large amount of tilapia
and is probably one of the largest producers of
cultured tilapia (top 5) in the world. Almost all the
tilapia cultured is consumed domestically. Tilapia are
cultured to improve family nutrition and economic
gain. With the increased interest in all-male tilapia
culture, use of export markets has increased.
LIMITS AND NEWDIRECTIONS FOR FISH CULTURE
SYSTEMS
PD/A CRSP research has examined the relative
merits of feeding and fertilization for tilapia production
given variable levels of stocking densities. The diversity
of production modes and technology combinations
used to produce tilapia reflect not only the high level
of adaptability of the species to water and nutrient
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
conditions, but also the fitness of the enterprise among
various socioeconomic categories of farmers.
The remainder of this report will be primarily
concerned with medium and low-investment systems.
Generally, only a handful of high-investment operators
are typically found in any PD/A CRSP country. There
are none in Rwanda, only two or three in Honduras,
more in the Philippines, and scores of high-investment
systems in Thailand. Farms in the industrial segment
of tilapia producers often serve more as collaborators
than recipients of PD/A CRSP technology. Managers
in this segment of the industry are interested in the
direct results of PD/A CRSP research. On occasion, PD/
A CRSP scientists serve as consultants to these firms.
CHAPTER FOUR
RESEARCH METHODS
SAMPLE AND DATA COLLECTION
Data were collected from tilapia farmers in four
PD/A CRSP countries; Rwanda, Honduras, Thailand,
and the Philippines. The following sections detail the
procedures employed in each country and the approach
used to analyze the data for this report.
Rwanda. Data were obtained from a sample of
121 active Rwanda fish farmers in eight
local administrative districts (communes)
during the Winter and early Spring of 1992
(Table 4.1). The 141 communes (or counties)
are the basic units of administration in
Rwanda. Several communes were chosen
to represent diversity in the nation's
regions; others were selected randomly.
Interviews were conducted with 115 active
fish farmers randomly selected from
extension rolls. About 43% of the
respondents were women. Figure 4.1
shows a map of Rwanda. 
Cyangugu
To contact respondents,
aquaculture monitors (extension
representatives) were asked to organize
and the interviewer. The Rwandan interviewer
conducted individual interviews in the native
Kinyarwanda language using a standardized set of
questions and response frameworks. Approximately 60
minutes were spent with each farmer.
An additional 16 active farmers who had not
received extension assistance were interviewed. These
emulator farmers had independently adopted fish
culture as a farm enterprise. They were selected in a
two-step process. First, fish farmers in areas not
receiving extension assistance were identified through
network sampling procedures and local informants (9).
General agricultural extension agents then provided
information about individuals who had constructed
fish ponds. Local residents also made referrals to
farmers who had ponds and neighbors provided
information about the owners of ponds visible from the
roadside.
TABLE 4.1. REGIONs SAMPLED AND NUMBER OF
RESPONDENTS, RWANDA, 1992
Rwanda Communes Number Percent
Gishamvu 9 7
Karago 17 14
Kayove 14 12
Kigembe 16 15
Ndusu 9 7
Nyamabuye 17 14
Tumba 14 12
Mugambazi 16 19
(Total) (121) (100)
Source: Department of Fisheries, 1992 Annual Report
meeting points and times with the farmers
Figure 4.1. Map of Rwanda.
13
RWANDA
Population
7.3 million
Area (sq. mi.)
10,169
City population
O Over 1,000,000
o Over 500,000
o Over 100,000
o Under 100,000
* Capital
25 mi
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL 
RESEARCH ON TILAPIA
Figure 4.2. Map of Honduras.
The interview schedule used in Rwanda in 1992
was revised and adapted for each of the three PD/A
CRSP countries surveyed in 1993-94. Additional
specification was obtained for production practices,
particularly feeding and fertilization, as these are the
14 central PD/A CRSP 
technologies examined here.
Honduras. Data were obtained from a sample
of 51 active Honduran fish farmers in nine of 15
Honduras departments during the Fall 1993. The
survey instrument was translated and all interviews
were conducted in Spanish. Tilapia farmers were
identified through referrals made by Peace Corps
volunteers working in fish culture, Honduran extension
personnel, and by farmers identifying neighbors raising
tilapia. The departments were chosen to represent the
major tilapia production regions in the country.
Interviews were conducted with 51 active fish farmers.
TABLE 4.2. REGIONs SAMPLED AND NUMBER OF
RESPONDENTS, HONDURAS, 1994
Honduras Departments Number Percent
Cortes 9 18
Santa Barbara 3 6
Copan 9 18
Comayagua 9 18
Atlantida 5 10
Colon 4 7
Francisco Morazon 1 2
Olancho 4 7
El Paraiso 5 10
Yoro 2 4
(Total) (51) (100)
I
Tilapia farmers were identified 
by
sampling lists of farmers purchasing
fingerlings at the Freshwater Aquaculture
Center at Central Luzon State University
in Mufioz. Sample farmers were asked to
identify neighbors raising tilapia who also
were approached for interviews. Because the sample
farmers were purchasing sex-reversed fingerlings at a
government station, the sample is likely biased toward
more avid adopters of technology. The provinces were
chosen to represent the major tilapia production region
in the country. Interviews were conducted with 51
active fish farmers. Figure 4.3 shows a map of the
country. Table 4.3 lists the sample provinces; these are
north of the City of Angeles in Central Luzon.
Thailand. Data were obtained from a sample
of 51 active Thai fish farmers in three of 75 Thai
provinces during Winter 1994. Tilapia farm operators
in Ayutthaya, Pathum Thani, and Nakhom Pathom
provinces Central Thailand were interviewed. The
survey was revised and adapted, then translated into
the Thai language. All interviews were conducted in
Thai.
Tilapia farmers were identified through
referrals made by Department of Fisheries extension
TABLE 4.3. REGIONs SAMPLED AND NUMBER OF
RESPONDENTS, PHILIPPINES, 1994
Philippine Provinces Number Percent
Nueva Ecija 9 16
Pampagna 17 30
Bulacan 14 25
Tarloc 16 29
(Total) (56) (100)
Source: Department of Fisheries, 1992 Annual Report
0
La Ceiba
reso
apeque
iayagua
S Danli
r nIHONDURAS
luteca Population
0 City 
population 
5.1 million
O Over 1,000,000 
Area (sq. mi.)
o Over 500,000 
43,277
o Over 100,000
S i o Under 100,000
75 mi 
* Capital
Figure 4.2 shows a map of Honduras; Table
4.2 details the name of each Department
and the number of interviews obtained
there.
Philippines. Data were obtained from
a sample of Philippine fish farmers in four
of 15 provinces on the main island of Luzon
during Winter 1994. Tilapia farm operators
in Bulacan, Nueva Ecija, Pampanga, and
Tarlac provinces were interviewed. The
survey was revised and adapted, then
translated into the Tagalog language.
Snta Ro
Ts
INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
UJ
Zamboanga b
/
. General
I3Ii
300 mi
PHILIPPINES
Population
64.9 million
Area (sq. mi.)
115,830
Ceib
Cagayan de Oro
avao
Santo
City population
O Over 1,000,000
o Over 500,000
o Over 100,000
o Under 100,000
* Capital
Figure 4.3. Map of The Philippines.
personnel, knowledgeable local individuals, and by fish
farmers giving identifying neighbors raising tilapia.
The provinces were chosen to represent major tilapia
production regions in south central Thailand, the major
aquaculture region in the country. Interviews were
conducted with 51 active fish farmers. Figure 4.4 shows
a map of Thailand. Table 4.4 lists the number of
respondents interviewed in each location; the sample
provirt es were in an area directly North of Bangkok.
Representativeness. The previous tables list
sampled communes or provinces for each country, but
certain cautions are in order. There are limits to the
ability of these data to extrapolate to wider populations
of fish farmers and other regions of the selected nations.
The 1992 Rwanda sample is more
representative than the samples drawn in the other
countries. It is nationwide, a larger number of
200 mi
Figure 4.4. Map of Thailand.
interviews was obtained, and the range of variability
in the population of fish farmers is smaller in Rwanda.
In Rwanda, the 121 farmers in the sample represent
3.9% of the 3,102 (1,950 group and 1,152 individual)
ponds in the country in 1990. Women are 24% of the
fish farmers in Rwanda and 43% of the sample (34).
Women were oversampled in the 1992 study. Molnar
previously examined the Rwanda data in detail, but
the aggregate findings are presented here allow
comparative analysis across four PD/A CRSP sites (44).
In contrast, the 1993 samples in Thailand and
the Philippines are smaller and represent a subset of
provinces in one key production area in the country. In
Honduras, the sample is drawn from a diverse set of
locales across the tilapia producing areas of the country,
although the number of cases is similar to the two Asian
sites. The sample sizes have restricted capability for
statistical estimation of population parameters; they do,
however, provide information about practicing fish
farmers where none is otherwise available.
TABLE 4.4. REGIONs SAMPLED AND NUMBER OF
RESPONDENTS, THAILAND, 1994
Thailand Provinces Number Percent
Ayutthaya 17 33
Pathum Thani 20 39
Nakorn Prathom 14 28
(Total) (51) (100)
THAILAND
Population
55.5 million
Area (sq. mi.)
198,456
City population
O Over 1,000,000
o Over 500,000
o Over 100,000
o Under 100,000
* Capital
SOCIAL, ECONOMIC, AND
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
ANALYSIS
Financial Analysis. Chapter 6 presents a
financial analysis of the CRSP PD/A research, using
partial net returns as a profitability indicator. Partial
net returns were calculated for various experimental
treatments as conducted and reported for each of four
CRSP countries. These analyses are based on average
1993-94 tilapia prices found in each country and the
quantity of tilapia produced for each experimental
regime. Local prices for fish and costs for the production
inputs were based on information from CRSP
researchers, survey information and the literature.
CRSP PD/A Data Reports for the Philippines,
Thailand, Honduras and Rwanda covering Cycles 1,11
and III of the Global Experiment were used to compare
fish yield and profitability of various combinations of
feed and fertilizer as applied under wet and dry season
conditions. The objective is to specify relationships
between input type, costs and relative viability of
treatments in each country. Of central interest are the
trials with the highest production and those with the
highest profitability; they are often not the same. Partial
net returns exclude costs for fixed and some variable
inputs that are assumed to be similar for all treatments.
The approach is further described and justified in
16 Chapter 
5.
Survey Data. In each country, the interview
schedules were edited to reconcile missing data,
ambiguous answers, and exceptional cases. The data
were keypunched according to precoded numerical
response categories on the printed questionnaire that
did not require translation. Opened-ended questions
eliciting verbatim comments or explanations were
cumulated in a separate process and presented here in
tabular form or summarized in the narrative as
appropriate.
Chapter 6 presents the data for each country
sample tabulated separately to facilitate comparisons
across the four sites (9). The objective is to document
the nature and circumstances of practicing tilapia
farmers who might adopt PD/A CRSP technologies.
The data establish the basic community, household,
labor, farming system, and marketing environment for
the conduct of fish culture at each site.
The survey data also are used in Chapter 7 to
portray production systems, technologies, and farmer
attitudes toward fish culture as they vary by farm size.
Pond area has a close correspondence to subsistence,
small-scale and commercial levels of aquaculture
production (32). Farm pond area is examined using
three categories - small, medium and large-
depending on the range reported in the surveys for each
country. The small pond area grouping is less than or
equal to .11, .65, and .96 hectares in Honduras, the
Philippines, and Thailand, respectively. The medium
pond area groupings in Honduras, the Philippines, and
Thailand are 0.12 to 0.65, 0.66 to 3.0, and 0.97 to 1.76
hectares, respectively. The large pond area groupings is
greater than .65, 3.0, and 1.76 hectares in Honduras,
the Philippines, and Thailand, respectively.
These categories correspond well with
production intensity levels and allow cross-country and
intra-country pond area comparisons. Rwanda data is
reported in the 'small' pond area category because of
its homogeneous low-intensity type of tilapia
production, regardless of actual pond area.
CHAPTER FIVE
PARTIAL NET RETURN ANALYSIS
OF PD/A CRSP EXPERIMENTAL TRIALS
INTRODUCTION
Although PD/A CRSP research has
endeavored to thoroughly specify the production
consequences of various combinations of feeding and
fertilization strategies, what matters to the farmer is
the approach that generates the most income and
produces the least risk. While not addressing the topic
of risk, this chapter treats the economic implications of
experimental tilapia production trials that PD/A CRSP
researchers conducted in Honduras, Thailand, the
Philippines and Rwanda.
Comparing nutrient input systems is important
for understanding farmer incentives for producing
tilapia. Better understanding of farmer motivations and
incentives may increase the likelihood that researchers
will develop and communicate sustainable aquaculture
systems. These data also may provide feedback about
the efficacy and relevance of PD/A CRSP research.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
One of the most critical PD/A CRSP research
topics is pond nutrient inputs. Nutrient input results
from PD/A CRSP research have been transformed here
into partial net returns for comparison to similar
production systems being used by farmers in
Honduras, Thailand, the Philippines and Rwanda. An
abbreviated economic analysis of the PD/A CRSP
nutrient experiments provides a context for interpreting
the relative profitability of various production strategies
in the different countries.
Farmer decisions about nutrient inputs will
dictate the possible production intensity levels. Input
prices and competition for these inputs further define
aquaculture production systems. This study adds to the
understanding of what affects tilapia culture choices
in these countries. Together, the survey data and PD/
A CRSP experimental data begin to establish a profile
of profitable tilapia farming systems in these countries.
The chapter places a partial net returns value
on PD/A CRSP Cycle I, II and III tilapia nutrient
research. Partial net returns reflect the income to a
farmer after a specific production cost for the input in
question is paid, not considering other variable or fixed
costs. Cycles refer to the stage of the PD/A CRSP
program that specified parallel or nearly parallel
experimental programs across study sites. These
comparisons have not been previously made.
Another objective is to examine the relative
efficacy of various experimental treatments in terms of
production and profitability. A comparison of relative
economic incentives for producing tilapia production
among the four countries is presented. Comparisons
of country-specific production systems reveal
similarities and differences in aquacultural
development among the study countries.
ECONOMIC ANALYSIS
Microeconomic analysis of aquacultural
operations has followed two primary directions-
econometric production function analysis and
enterprise budget analysis (3,59). Both methods have
been adapted to aquaculture from their long-standing
use in traditional agriculture (5,24,33,58).1
Econometrics. One approach to production
economics is through the use of econometrics in the
development of production functions that explain
output quantities through a linear combination of input
variables (5,33). Production functions are regression
equations that incorporate input quantities as
independent variables to explain the quantity produced
(14,28,49,50,66).
The equation coefficients and their significance
levels reveal the relative contribution of various factors
into the production system. Marginal analysis is
conducted on each significant variable. Optimal input
levels at given fish selling and input prices can then be
determined. As prices change, theoptimal levels change
and this approach handles this variability well. In this
sense, the econometric approach is dynamic while the
enterprise budget approach is static. However, the
detailed quantitative input data required for the
econometric methodology are beyond the scope of the
present study.
Enterprise Budgeting. A farm is composed of
a bundle of enterprises or money-making activities;
each enterprise can be described in terms of expenses
and revenues. Enterprise budgets list and quantify
items producing income or requiring expenditures for
the production of a commodity on a representative
farm. Several indicators of economic viability result
from this approach; the results also suggest optimal
strategies for farmers 
(7).
2
Profit can be described as the quantity
harvested multiplied by the selling price minus
operating costs. Full enterprise budgets include
receipts, variable costs, and fixed costs. Fixed costs
include payment of loan principal and interest for items
such as pond and building construction and land
purchases, as well as depreciation and taxes. Net
returns are the full enterprise budget's measure of
profitability. Partial enterprise budgets charge only
variable costs - in this study, costs of the different feed
1
A third approach not further examined here is the internal
rate of return. Primarily used as means for evaluating
alternative public sector investments, this result can be
obtained by using net present values of long-term receipts
and expenses. Taking a longitudinal perspective, the internal
rate of return is often used in investment analysis to compare
projects in terms of alternate uses of the funds invested as
they might be invested over a period of time.
2
Breakeven prices and quantities are also derived from
this analysis and can be useful in determining an enterprises'
associated risk. Farm plans can then be developed on the
basis of enterprise budgets and assumptions about available
resources (land, labor, capital) to optimize profits or minimize
costs. Cash flows developed from the farm plans are used
in financial planning and loan procurement.
17
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
and fertilization treatments. Partial enterprise
budgeting analysis is used to evaluate net changes in
income from a change in production practice- i.e.,
the various treatments in an experiment - over the
baseline, no-treatment condition.
Enterprise budgeting allows net returns to be
calculated and compared across experimental
treatments. Price variability is difficult to anticipate;
optimized farm plans are only as good as the
information included in them. Thus, overall economic
stability, specifically for marketing and input/output
prices, can dramatically affect the farm plan viability.
The nature of the interview data used here to
portray the circumstances on fish farms limits the extent
and detail of the analysis, but cross-national and farm
size differences can be examined. Others (10,64) note
that farmer recall of the quantities of various inputs
over the production cycle usually is neither thorough
nor accurate. However, stocking and harvest quantities
do tend to be recalled with greater accuracy. Continuous
collection of data over the production cycle is necessary
for accurate enterprise budgeting or econometric
regression analysis.
In the following financial analysis of the results
of PD/A CRSP experimental trials, partial net returns
have been used as the profitability indicator. We present
partial net returns analyses of the experimental
treatments in each of four CRSP countries. Partial net
returns exclude costs for fixed and some variable inputs that
are assumed to be similar for all treatments. Thus, these
returns are high and do not - are not expected to - mirror
actual farm net returns.
The partial net returns approach does allow a view
of the effects of local costs of tilapia fingerling and nutrient
inputs on profitability. Only when biologically sound
production systems are analyzed in terms of local prices
can the actual degree of profitability and sustainability
be seen.
Time, recall, and respondent burden
considerations constrain obtaining detailed
specification of production data in interviews.
Additionally, the multi-disciplinary objectives of this
study - sociological, biological, and economic-
required the survey be manageable in the field, i.e., not
too onerous for the respondent in terms of time and
mental effort. Thus, a more quantitative production
input/output full enterprise budget approach has not
been taken in this study If such an analysis is to be
conducted in the future for tilapia farmer systems, then
continuous monitoring of the inputs supplied
throughout the production cycle must be done.
PD/A CRSP NUTRIENT EXPERIMENTS
PD/A CRSP researchers have experimented
with varying nutritional inputs and their effect on
tilapia production. Results have allowed specification
of the required organic inputs, chemical fertilizers, and
commercial feeds for efficient growth. Economic
analyses have shown some of these production schemes
to be profitable, even though some of the inputs tested
are not widely available 
in some of the countries.
3
The relative profitability of various approaches
represented in on-farm trials has been conducted by
Honduras PD/A CRSP researchers (63). Experimental
treatments differ in type and quantity of inputs chosen
by farmers. Subsistence, small and medium-scale
farmers usually use a diverse mixture of inputs as
opposed to the limited input combinations used in PD/
A CRSP research regimes. In fact, it would be difficult
to conduct research paralleling the variety of inputs
used by farmers. On-farm tests of PD/A CRSP nutrient
regimes have had some difficulty maintaining the
integrity of treatment requirements. Farmers sometimes
failed to maintain nutrient schedules throughout the
production cycle thus making comparisons to field
station trials difficult.
Receipts in this analysis are based on average
1993-94 tilapia prices found in each country and the
quantity of tilapia produced for each experimental
regime. All experiments in Cycles I, II, and III Work
Plans stocked one fish per square meter. Local prices
for fish and costs for the production inputs were based
on information from PD/A CRSP researchers, survey
data, and the literature, Table 5.1.
All experimental production data came from
the PD/A CRSP Data Reports for the Philippines,
Thailand, Honduras and Rwanda covering Cycles I,1II
and III of the Global Experiment. These volumes may
be referenced for specific input quantities (PD/A
Collaborative Research Data Reports). The point here
is to determine relationships between input type, costs
and relative viability of treatments in each country. Of
3
For Rwanda see (20,34,35); Thailand (22,39,61);
Philippines (36); and Honduras (26,63).
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
central interest are the trials with the highest production
and those with the highest profitability; they are often
not the same.
Rwanda. PD/A CRSP Cycle I experiments
included chemical fertilization - triple
superphosphate (TSP) - trials during the dry and wet
seasons. This experiment examined the variation in
production when very low levels of fertilizer were used.
There were no Cycle II experiments. In Rwanda, Cycle
III experiments included dried chicken manure
treatments during the dry and wet seasons.
In nearly every case, dry season yields
exceeded wet season yields. However, seasonal
differences were not thought to be the cause of
production differences. Researchers contend that these
differences were more affected by the newness of the
ponds and carryover effects from the first seasonal
experiments to the next season's experiments. New
ponds built in the clay soils are more "exposed and
reactive soils" to input nutrients. Secondly, carryover
effects from the wet season experiments conducted in
the same individual ponds had residual fertilization
effects for the dry season experiments.
Tilapia yields in the Rwanda context are
presented in Figure 5.1 and partial net returns are
presented in Figure 5.2. The highest yields and partial
net returns were obtained using chicken manure during
the dry season. The 500 kg/ha/week of chicken
manure, dry season, treatment had a partial net return
of $1,532 for a 150-day cycle and an annualized
production of 2,590 kg/ha.
The comparable treatment during the wet
season produced 968 kg/ha/year with a partial net
return of $466 for a 150-day cycle. The dry season 250
kg/ha/week and 125 kg/ha/week chicken manure
treatments produced 1,917 and 1,244 kg/ha/year,
respectively; and partial net returns were $1,170 and
$767 per ha per 150 day cycle, respectively. The
comparable wet season production yields for the 250
and 125 kg/ha/week of chicken manure input were
669 and 377 kg/ha/year, respectively; partial net
returns were $350 and $197 for a 150-day cycle,
respectively.
The Cycle I triple superphosphate yields were
designed to estimate seasonal differences between wet
and dry seasons on fish production as well as biological,
chemical and physical conditions. However, pond
construction delays did not allow these seasonal
determinations, instead two 150 day experiments were
conducted to estimate natural production levels. All
ponds received 8 kg/ha/week of TSP to decrease wide
differences in natural variability. Production yields
between the two experiments did not significantly
differ and were approximately 646 kg/ha/year - a
partial net return of $401 per hectare per 150 day
production cycle.
Honduras. PD/A CRSP Cycle I research
included TSP trials during the dry and wet seasons.
Cycle II trials included chicken manure, cow manure
and urea-TSP combinations applied during the dry and
wet seasons. Cycle III trials used layer chicken manure
at 125, 250, 500, and 1,000 kg/ha/wk rates during the
dry and wet seasons.
Tilapia yields in Honduras are presented in
Figure 5.3 and partial net returns are presented in Figure
5.4. The highest partial net returns resulted from the
use of chicken manure at 1,000 kg/ha/week in the dry
and wet seasons. There was no apparent seasonal effect.
The 500 kg/ha/wk CM treatment rate similarly shows
no seasonal effect. However, the next highest
production and partial net return was obtained by the
575 kg/ha/wk CM treatment during the dry season.
The same treatment for the wet season had much lower
production and returns.
Opposite seasonal differences occurred for the
250 kg/ha/wk CM treatment rate. Treatments using
only chemical fertilization, TSP plus urea, had
production yields falling between the CM125 and
CM250 treatments, Figure 5.3. However, the associated
partial net returns were lower than any of the CM
treatments, Figure 5.4. When comparing TSP alone with
TSP plus urea, the combination increased both
production and profitability.
Philippines. PD/A CRSP Cycle I research
included TSP trials during the dry and wet seasons.
Cycle II trials included (a) no feeding or (b) feeding
with supplemental chicken manure or (c) feeding with
supplemental inorganic fertilizer (TMP, 16-20-0). Wet
season chicken manure fertilization trials were
conducted at 125, 250, 500, and 1,000 kg/ha/wk rates.
No dry season replication of these treatments occurred.
The following trials and combinations were
conducted during the dry and wet seasons: (1) no feed
and low chicken manure; (2) no feed and high chicken
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
TABLE 5.1. PRICES OF TILAPIA AND VARIABLE INPUT COSTS FOR Dry and wet season
PARTIAL NET RETURN 
ANALYSIS OF THE PD/A 
CRSP WORKPLANS 
TSP trials and wet season 
trials
I, II, AND III FOR FOUR PD/A CRSP 
COUNTRIES, 1994. with 
chicken manure
produced good yields, Figure
Country Tilapia 
Fingerlings 
Feed TSPI TMP2 
Urea CM3
5.5 and were viable financially,
$/kg $each $/kg $/kg $/kg $/kg $/kg Figure 5.6. Treatments
Rwanda 1.60 0.025 - 0.30 - - 0.015 combining chicken manure
Thailand 0.48 0.004 - 0.47 - 0.27 0.010 with TMP were also
Honduras 1.33 0.019 - 0.34 - 0.28 0.016
Philippines 1.63 0.005 0.25 
0.22 0.22 - 0.010 economically 
viable in both
1 TSP = triple superphosphate 
seasons. However, when feed
2 TMP = triple monophosphate was 
provided in addition to
3 CM = chicken manure and litter 
chicken manure, negative
partial net returns resulted,
Figures 5.7 through 5.10.
Kilograms/hectare/year 
When triple monophosphate 
(TMP) was part
of a schedule of feed and chicken manure, production
Wet season soared above all other nutrient regime treatments,
Figure 5.9. However, 
three out of four 
treatments
3,000 Dry season resulted in negative net returns, Figure 5.10. The
negative returns are caused by the high cost of
2,500 commercial 
feed which is not balanced by sufficient
added income from the additional fish produced.
2,000
The two treatments having the greatest returns
1,500 
were the 1,000 kg/ha/week 
CM (wet season) treatment
and the combination treatment of 405 kg/ha/week CM
1,000
i500 Dollars/150 day cycle/hectare
0A$1,600--Wet season
0 CM CM CM TSP $1,600 
Dry season
500 250 125 8 
1,400
Treatment
1,200
Figure 5.1. Tilapia yields in Rwanda, Cycle I-III work plans.
CM=chicken manure and litter; TSP=triple superphosphate; the 1,000
number that follows is a weekly rate in kilograms per hectare.
manure; (3) no feed, low chicken manure and high TMP; 800
(4) no feed, high chicken manure and high TMP; (5) 600
high feed and low chicken manure; (6) high feed and
high chicken manure; or (7) high feed and high chicken 400
are presented in Figures 5.5, 5.7 and 5.94 and associated 200
partial net returns in descending order are presented 0 CM CM CM TSP
in Figures 5.6, 5.8 and 5.10. CM CM CM TSP
4
FD represents commercial feed (20% crude protein) inputs
as a total input quantity for the 150 day cycle. 
Chiclen Treatment
manure treatments follow the terms used in the preceding
figures, i.e., the quantity of CM applied per week per hectare
.  
Figure 5.2. Partial net returns forTilapia production in Rwanda,
The same terms refer to the TMP (16-20-0) in these figures as Cycle I-III work plans. Abbreviations 
same as in Figure 5.1.
for the preceding figures, i.e. a weekly rate per hectare. Refer
to the PD/A CRSP Data Reports, Cycle I, 11, and III for specific
details of each treatment.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Kilograms/hectare/year
I CM CM CM CM U29/ CM TSP
1000 575 500 250TSP60 125 50
1 Treatment
Figure 5.3. Tilapia yields in Honduras, PD/A CRSP Cycle I-III
work plans. CM=chicken manure and litter; U = urea; TSP=triple
superphosphate; the number that follows is a weekly rate in
kilograms per hectare. In the wet season, the actual U29/TSP60
treatment was U31/TSP49.
CM CM CM CM U29/ CM TSP
1000 575 500 250TSP60125 50
Treatment
plus 240 kg/ha/week TMP (dry season), Figures 5.6
and 5.10, respectively. In contrast, the highest total yield
occurred from three of the treatments using a
combination of commercial feed plus chicken manure
plus TMP, Figure 5.9.
The highest production resulted from the
treatment using the combination of 5,150 kg of feed per
cycle plus 278 kg/ha/wk CM plus 50 kg/ha/wk TMP
during the wet season. The combined higher cost of
these inputs kept the partial net returns lower than the
CM125, CM250, CM500 and CM1000 (kg/ha/wk CM)
treatments, Figures 5.10 and 5.6.
Thailand. PD/A CRSP Cycle I Thailand
experiments used inorganic TSP fertilizer at 8 kg/ha/
month during the dry and wet seasons. Cycle II
experiments included trials using chicken manure and
urea plus TSP during the dry and wet seasons. Cycle
III research included chicken manure trials during the
dry and wet seasons.
Tilapia yields in Thailand are presented in
Figure 5.11 and partial net returns are presented in
Figure 5.12. The economically viable enterprises
involved only chicken manure (waste and bedding
substrate). Production was good for all chicken manure 21
treatments. However, no treatments using TSP alone
or with urea were economically viable.
There was a distinct seasonal effect for chicken
manure application. Rates used in the dry season had
better results than in the wet season for three out of
four chicken manure application rates. Chemical
fertilizers produced good tilapia yield, Figure 5.11. The
low price paid for tilapia in Thailand and relatively
higher cost of chemical fertilizers in relation to chicken
manure led the partial net returns for the chemical
fertilizer treatments to be negative even though
production was good.
In general, the regimes using the most chicken
manure had the highest production rates, Figure 5.11.
Financially, the partial net returns for the 1,000 kg/ha/
wk chicken manure treatment were less than those for
the 500 kg/ha/wk treatment, Figure 5.12. In this
instance, the treatment with the highest production is
not the most profitable.
Figure 5.4. Partial net returns for Tilapia yields in Honduras,
PD/A CRSP Cycle I-III work plans. Abbreviations, same as in
Figure 5.3.
SOCIAL, 
ECONOMIC, 
AND INSTITUTIONAL 
IMPACTS 
OF AQUACULTURAL 
RESEARCH 
ON TILAPIA
Kilograms/hectare/year
1, 500 
11111 Wet season
19400Dry 
season1,400/
1,300
1,200
1,100
1,000
0
CM CM TSP CM CM
1000 500 50 125 250
Treatment
Figure 5.5. Tilapia yields in the Philippines, PD/A CRSP Cycle I
and II work plans. CM=chicken litter; U = urea; TSP=triple
superphosphate; the number that follows is a weekly rate in
kilograms per hectare.
Dollars/i 50 day cycle/heCtare
$720(LI wet season
Dry season
700
680
660
640
620
600
0 600 1, 200 1,800 2,400 3,000
1 Kilograms/hectare/year j
Figure 5.7.Tilapia yields for dry season production in the Philippines,
PD/A CRSP Cycle 1I work plan. CM=chicken litter; U = urea;
TMP=triple monophosphate; the number that follows is a weekly
rate in kilograms per hectare; FD=commercial feed;the number that
follows is the amount applied over the production cycle.
CM95 + TMP240
FD4458 + CM95
FD4458 + CM405
FD4968 + CM405
+ TMP240
CM405 + TMP240
($1,000) ($700) ($400) ($100) $200 $500 $800
I Dollars/i 50 day cycle/hectarej
Figure 5.8. Partial net returns for dry season Tilapia yields in the
Philippines, PD/A CRSP Cycle 11 work plan. Abbreviations same
as in Figure 5.7.
CM95 + TMP240
FD4458 + CM95
FD4458 + CM405
FD4968 + CM405
+ TMP240
CM405 + TMP240
22
OFAQUACULTURAL RESEARCH ONTILAPIAAND INSTITUTIONAL IMPACTS
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Kilograms/hectare/year
CM95 + TMP206
CM95 + TMP50
CM278 + TMP206
FD5151 + CM95
+ TMP50
CM278 + TMP50
FD5103 + CM95
+ TMP50
FD4880 + CM95
+ TMP206
FD5150 + CM278
+ TMP50
0 600 1,200 1,800 2,400 3,000
Kilograms/hectare/year
CM CM CM U30/ CM
500 1000 125 TSP100 250
... . .L .... .
Figure 5.9. Tilapia yields for wet season production in the ireatment
Philippines, PD/A CRSP Cycle II work plan. CM=chicken manure
and litter; U = urea; TMP=triple monophosphate; the number Figure 5.11. Tilapia yields in Thailand, Cycle I-III work plans.
that follows is a weekly rate in kilograms per hectare; CM=chicken manure and litter; U = urea; TSP=triple
FD=commercial feed;the number that follows is the amount superphosphate; the number that follows is a weekly rate in
applied over the production cycle, kilograms per hectare.
Dollars/150 day cycle/hectare
CM95 + TMP206
CM95 + TMP50 
$1,000 
Dry season
CM278 + TMP206 
800
FD5151 + CM95 
600
+ TMP206 400
CM278 + TMP50
200
FD5103 + CM95 H
+ TMP50 0
FD4880 + CM95
+ TMP206 
($200)
FD5150 + CM278
+ TMP50 ($400)
($800) ($500) ($200) $100 $400 $700 ($600) CM CM CM U30 CM TSP
CM CM CM U30/ CM TSP
Dollars/150 day cycle/hectare 500 1000 125 TSP100 250 8
Figure 5.10. Partial net returns for Tilapia yields in wet season Treatment
production in the Philippines, PD/A CRSP Cycle II work plan.
Abbreviations same as in Figure 5.9. Figure 5.12. Partial Net returns forTilapia yields in Thailand,
PD/A CRSP Cycle I-Iil work plans. Abbreviations same as in
Figure 5.11.
23
TSP
8
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
CHAPTER Six
SURVEY RESULTS: PATTERNS OF
TECHNOLOGY UTILIZATION
This chapter describes the practices, technical
proficiency, and receptivity to the adoption of PD/A
CRSP technologies and production regimes among
tilapia farmers. The information in this chapter provide
a comprehensive profile of the socioeconomic niche for
fish farms in each locale. The analysis shows the survey
responses for comparable questions across the four PD/
A CRSP countries examined in this study. From these
data, central patterns of comparison and difference in
practice and approach to tilapia production and
technology utilization can be discerned.
RESPONDENT CHARACTERISTICS
Respondent characteristics provide some basis
for assessing the potential representativeness of the data
examined here. Table 6.1 describes the individual and
household characteristics of study respondents.
Although women make vital contributions to food
production and to aquaculture activities, most of the
respondents in this study were women. A woman
24 conducted the interviews in Thailand, though men
were interviewers in the other sites.
Women comprised about a fourth of the
respondents in Rwanda and
Thailand, but only about 
a tenth TABLE 
6.1.
of the Honduras and Philippine
tilapia farmers we contacted.
The Rwandan farmers were
younger and the Philippine
farmers tended to be older than Gender 
of responde
Male
farmers in the other 
countries. Female
Most farmers were married. A
somewhat higher proportion 
of Age of ress thapondent5
the Philippine farmers were 25-34
over age 65. 35-44
45-54
Nearly 
all the 
55-64
Rwandan, Honduran, and
Philippine households 
had Respondents 
with ch
children under age ten, but only Under0age 18
about half the Thai families had Over age 18
young children. Philippine Number of people in
families had the fewest children Two or less
age ten to 18 and the largest Three to 5
proportion with children over Six or more
age 18. Rwandans 
had the (Number)
largest households, as 65% reported six or more
members. About half the respondent households in the
other countries were that large.
LANDHOLDING
Table 6.2 profiles the landholding of study
respondents. Honduran farms were much more
fragmented than the others, as all respondents reported
nine or more parcels in their farms. In the other nations,
most had relatively consolidated holdings of one to
three pieces of land.
About five percent of the Rwandan
respondents did not own any land, primarily young
people farming in groups formed to use communal
lands for the purpose of aquaculture. In the face of
burgeoning numbers of young people seeking farm
land, local authorities prefer to grant marais land use
rights to groups rather than individuals. In Thailand,
19% said they did not own land. Nearly all respondents
in Honduras and the Philippines owned some land.
These data also reflect on the relative standing of fish
farmers in the social structure of each nation and the
level of development in each context. Young Thai
RESPONDENT CHARACTERISTICS, TILAPIA FARMS
N FOUR PD/A CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct. Pct. Pct.
it
71 86 91 76
29 14 9 24
12 8 4 4
25 24 20 13
33 25 23 32
13 27 21 25
12 12 14 19
5 4 18 7
ildren:
81 98 98 47
71 51 38 45
41 41 57 43
household?
1 8 15 6
34 38 40 47
65 54 45 47
(136) (51) (50) (56)
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
FARM ENTERPRISES
TABLE 6.2. LAND OWNERSHIP, 
TILAPIA FARMS IN FOUR 
The farm enterprises 
maintained by
PD/A CRSP 
COUNTRIES, 1994 
tilapia farmers 
are portrayed in 
Table 6.3.
Rwanda Honduras Philippines Thailand 
Chickens were the most commonly
Pct. Pct. Pct. Pct. reported animal enterprises, except in
Number of pieces of land in your farm? Rwanda. In Rwanda, 
83% said they had
1-3 parcels 18 0 93 94 cattle, nearly as many said they had goats,
3-9 parcels 63 0 
7 4 and about 41% had pigs. Cattle 
were
9 or more 19 100 0 2 nearly as popular in Honduras, followed
How much land owned? 
by pigs. In the Philippines, the 
second
None 5 0 2 19
Some or all 95 100 98 81 most common animal enterprise was
Some or all 95 100 98 81
How much land do you rent from others? "other", reflecting the widespread
None 43 98 
89 56 husbandry of 
water buffalo. About a third
Some 69 2 11 44 of the farmers in the Philippines reported
How much land do you rent to others? 
cattle, goats, pigs, and ducks.
None 92 100 95 85
Some 8 
0 5 15 
In Thailand, about a third had 
ducks
Compared to other farmers, how much land do you have? 
and pigs. No one single animal enterprise
More 10 43 33 26 dominated the farming system in the Thai
About the same 15 43 51 42
Less 75 14 16 
32 sample. The Thai farmers also were more
(Number) (136) (51) (50) (56) likely to integrate animal production with
farmers in the study area face rising land
prices associated with the growth of the TABLE 6.3. ENTERPRISES ON TILAPIA FARMS, FOUR
PD/A CRSP COUNTRIES, 1994
greater Bangkok economy.
Rwanda Honduras Philippines Thailand 25
Hondurans and Filipinos did not 
Pct. Pct. Pct. 
Pct.
seem to rent much land from others, but What types of farm animals do you raise?
in Rwanda two-thirds said they rented Cattle 83 62 32 15
land from others. About 44% of Thai 
Goats 78 5 32 
0
farmers rented land in; they also were Pigs 41 45 43 31
Chickens 23 69 80 51
more likely to rent land out. Only eight Ducks 14 19 32 
36
percent of the Rwanda farmers said they Rabbits 11 5 0 0
rented land to others. 
Other 19 
12 50 
8
Do you raise animals with your fish pond?
No 100 72 60 31
Three-quarters of the Rwandan Yes 
0 28 40 69
fish farmers felt that they had less land What enterprises give most of cash income?
than their neighbors; a third of the Thais Vegetables 0 49 36 9
felt the same way, compared to 15% in the Rice 0 2 56 36
other countries. About half the Philippine Bananas 
19 2 13 31
Fruit crops 0 2 27 53
respondents said "about the same as Fish 0 30 96 93
people around here." Hondurans were Sugar cane 0 4 4 0
about equally split between more and the 
Livestock 0 34 
25 62
Corn/Maize 10 15 9 0
same amount of land ownership. Other 36 49 9 0
Different segments of the rural populace Sorghum 29 0 0 0
tend to participate in fish culture in each Cabbage 10 0 
0 0
Sweet Potatoes 83 0 0 0
nation; more Honduran producers Beans 10 0 0 0
tended to be drawn from the rural elite. Taro 16 0 0 0
Cassava 63 0 0 0
Irish Potatoes 12 0 0 0
Sweet Peas 9 0 0 0
(Number) (136) (51) (50) (56)
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
26
aquaculture, as more than two-thirds of the Thailand
sample reported raising tilapia with some type of
animal enterprise. At present, integrated fish-animal
production systems are only in the demonstration
phase in Rwanda and are less widely adopted in the
Philippines.
Fish was the main source of cash income for
about 90% of the Philippine and Thai farmers. Sweet
potatoes were identified as providing most cash income
by more than 80% of the Rwandan farmers, followed
by cassava. In Honduras, vegetables and other crops
(mainly coffee) provided most farm income.
POND LOCATION AND WATER SOURCE
More than 80% of the Rwandan farmers had
but a single pond, as shown in Table 6.4. In contrast,
deter theft.
TABLE 6.4. POND LOCATION AND WATER SOURCE, TILAPIA FARMS IN
FOUR PD/A CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct. Pct. Pct.
How many ponds do you have on your land?
One 84 16 9 39
Two 11 12 20 26
Three or more 5 72 71 35
What is the surface area of the ponds on farm?
< .25 hectare 76 48 34
.25 to 1 hectare 20 48 58
> 1 hectare 4 4 8
Have you had problems getting enough water?
No 76 82 66 45
Yes 24 18 34 55
Where are ponds in relation to house?
Next to house - 66 36 79
<1 kilometer 12 35 6
1 to3 - 2 22 9
More than 3 20 7 6
Water source for the ponds on this farm?
Well - 2 9 0
Spring - 8 7 0
River or stream - 18 14 2
Lake - reservoir - 48 0 2
Irrigation canal - 14 13 64
Collected runoff - 0 16 0
Combination - 10 41 32
Water supply to pond?
Pumped 0 16 42 96
Gravity flow 100 82 38 2
Combination 0 2 20 2
(Number) (136) (51) (50) (56)
located next to the house, as were two-thirds of the
Honduran ponds and a third of the Philippine farms.
In Rwanda, fish ponds are always located in
the valley bottoms (marais). These lands are
communally owned and individual farmers are given
relatively secure use concessions, but no houses are
permitted. Consequently, ponds usually are some
distance from homesteads built on the nation's
mountainous hillsides. In some areas, group or family
members take turns guarding harvestable fish at night.
Some farmers hire watchmen to protect the ponds and
other crops.
FISH FEEDING
Farmers in the four countries fed their tilapia a
variety of different items reflecting differences in the
more than 70% of the Philippine and
Honduran farmers had more than three
or more ponds. In Thailand, slightly more
than a third had three or more ponds; a
similar proportion had but a single pond.
About three-
quarters of the Honduran farmers had
less than a quarter hectare of ponds; half
the Thai farmers had ponds this size; but
only a third of the Philippine farmers did.
Most Rwandans obtained water for
their ponds from streams or springs.
Honduran farmers supplied their ponds
from a variety of sources, most frequently
identifying lakes or reservoir sources.
Thai farmers depended most on irrigation
canals, while Philippine farms indicated
the least dependence on any single
source. All Rwandan ponds used gravity
flow, but most Thai farmers had pumps.
More than half the Thai sample
reported problems getting enough water
to keep ponds full. A third of the
Philippine farmers said so, as did a
quarter of the Rwandans.
The location of the fish pond relative
to the household is significant. Ponds
near households are easier to monitor.
Family members can attend to the pond
as well as give regular surveillance to
About 79% of the Thai fish ponds were
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
intensity of aquaculture practice in each TABLE 6.5. FEEDING 
PRACTICES, TILAPIA FARMS IN
nation, Table 6.5. As discussed earlier, 
FOUR PD/A CRSPCOUNTRIES,1994
feeding and fertilization represent 
Rwanda Honduras Philippines Thailand
overlapping activities for the tilapia
farmer. In Rwanda, respondents Pct. Pct. Pct. Pct.
primarily understood questions about 
Items most often fed?
Termites 6 0 0 0
feeding in terms of the amount 
and kind Bees wax or larvae 
2 0 0 
0
of organic materials they put in their Leaves 87 0 0 0
ponds. In the other sites, farmers Manure 67 
0 0 0
primarily understood feeding to refer 
to Sorghum beer waste 32 
0 0 0
Kitchen waste 0 14 2 12
the use of commercial, purchased feeds. Fresh vegetation 0 16 6 34
Rice bran 0 14 61 34
Leaves and manure were the Dead 
animals 0 0 0 
8
Slaughter waste 15 4 
0 2
most common items in Rwanda. Chicken Commercial feed 0 41 32 42
litter and commercial feed were most Chicken litter 0 0 37 45
frequently mentioned in Honduras. In Other 
8 57 0 2
Grass cuttings 28000
Thailand, farmers most often 
utilized rice Grass cuttings 
28 0 0 
0
Compost 28 0 0 0
bran, commercial feed, and chicken litter. Inorganic N 0 8 48 61
A similar pattern was noted in the Chicken feed 0 0 
2 0
Philippines, although rice bran was used 
Fish feed 0 0 
0 0
more often. 
Use commercial feed?
Only commercial 21 10 7
Mainly commercial 10 24 20
Commercial feed was not used in Both equally - 6 2 0
Rwanda; two-thirds of the Hondurans Use no feed 
1001 63 64 73
did not use commercial feed; and about Type commercial feed usually purchased?
None purchased 10014320
half the Philippine respondents 
did not None purchased 
1001 43 25 
0
Rice bran 0 14 35 36
use commercial feed. Thai farmers were Rabbit pellets 0 8 0 0
most dependent on commercial inputs to Chicken feed 0 2 3 2
raise their tilapia crops. They also used Fish 
feed 0 21 33 
28
Other 0 12 0 34
the most diverse 
variety of feeds, 
(Number) 
(136) (51) 
(50) (56)
reflecting the high level of availability of
different feed types and a greater 
1
Imputed data
willingness to use feeds for other animals
for the fish as well. Philippines. Given the pervasive use of integrated
systems in Thailand, ponds were most frequently
Honduran and Rwandan farmers were most fertilized with poultry manure in that country. Thai
likely to report inadequacies in feed availability on their farmers also were more likely to apply lime to their
farms. About seven percent of the Rwandan farmers ponds to increase the alkalinity (pH) of the pond and
said that they never had enough inputs for their ponds. foster primary productivity.
FERTILIZATION About 73% of the Thai farmers fed their fish
Table 6.6 shows the use of fertilizer in the four several times a day. The greater incidence of integration
samples. In Rwanda, commercial fertilizer represents with poultry and duck production that require multiple
a cash outlay that subsistence farmers prefer to avoid dalfeinsitrlyplsovrothtlpaco.
and, it generally is not applied to fish ponds. Because dailty fueedns litryially ltdecl over thetiaacrp
commrcil frtiize isnotuse orrecmmededforfishpond, so feed and manure are nearly continuously
fish ponds, these questions were not asked in Rwanda. deposited into the pond.
Hondurans typically use cattle and chicken Honduran farmers reported a high level of
manure as fertilizer for their ponds. Chicken manure attentiveness to their ponds. About a quarter of the
is the most frequent pond fertilizer in Thailand and the Rwandans fed their fish several times a week or less
27
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH 
ON TILAPIA
TABLE 6.6. FERTILIZATION PRACTICES, TILAPIA FARMS IN FOUR
PD/A CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct. Pct. Pct.
Pond fertilizer used?
1
Urea - 0 14 0
0-46-0 - 0 0 9
18-46-0 (dap) - 10 2 0
Other N-P-K - 24 79 49
Chicken manure - 29 70 53
Cattle manure - 37 4 6
Compost - 0 2 25
How often do you fertilize your ponds?
Several weekly - 27 0 69
Weekly - 18 11 10
Several monthly - 14 19 2
Monthly - 10 21 0
Less often - 21 43 4
Never - 10 6 15
Limed ponds last year?
No - 57 95 26
Yes - 43 5 74
How often visit ponds?
Several daily 0 39 34 73
Every day 53 37 36 19
Almost every day 2 14 25 0
Several weekly 32 2 5 6
Once a week 13 6 0 0
Several monthly 0 2 0 2
Time usually spent when you visit your pond?
Hour or less 34 18 4 79
About an hour 48 30 5 11
Two or 3 hours 14 20 16 4
More than 3 5 32 75 6
(Number) (136) (51) (50) (56)
1
Multiple responses possible
often. Feeding in the Rwanda case refers primarily to
the provision of manure and other inputs, some of
which are directly consumed. These items mainly serve
as nutrients to foster primary productivity in the ponds.
Rwandan farmers indicated the least attentive
approach to fish farming, as only about half said the
ponds were visited every day. Philippine farmers spent
the most time with their ponds when they visited them;
Thai farmers the least.
FINGERLINGS
A fundamental input to aquaculture
production is the seed stock or fish that begin the crop
cycle. Tilapia is a species that can easily
spawn in ponds without farmer assistance,
but most producers rely on hatcheries to
provide fingerlings of uniform size and
characteristics, often only faster-
growing males. Spawning other cultured
species - such as Asian carps, milkfish, or
catfish - require special skills, procedures,
or facilities. Fingerling availability is an
important consideration in species selection,
especially for polyculture systems.
Government hatcheries have generally
been effective in supplying tilapia fingerlings
in the early stages of aquacultural
development. As the aquaculture industry
expands, the development of private-sector
fingerling producers is crucial. In periods of
rapid growth, fingerling needs cannot
usually be met by government facilities.
Rwandan farmers are dependent on
government hatcheries for the production of
fingerlings of known lineage and quality, as
no private hatcheries yet exist. Even though
no commercial fingerling production has yet
developed in the country, fingerling sales are
reported between neighboring farmers.
Mixed- sex fingerlings from local ponds
constitute the primary source of most fish
crops in Rwanda. Table 6.7 profiles the
fingerling sources used by fish farmers in the
other countries. Similarly, few private farm
dealers have evolved in Honduras. The
private sector provided fingerlings to more
than 80% of the Thai farmers and about 37%
of the Philippine operators. In each country,
most farmers were using the Oreochromis
niloticus species.
Thai and Philippine farmers tended to densely
stock the smallest fingerlings available. Honduran
farmers tended to stock somewhat larger fingerlings.
All-male tilapia were stocked in each country, although
mixed-sex culture was the normal mode of production
in Rwanda.
Chemically-induced sex reversal was the most
commonly employed method of producing all-male
tilapia fingerlings in all the sites. It is notable that 84%
of the Thai farmers did not know the method by which
all-male tilapia fingerlings were produced.
28
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
STOCKING AND GROW-OUT PRACTICES
Table 6.8 suggests that most farmers are
growing but a single crop of tilapia each year in
Thailand. In Honduras, almost half reported two or
more crops, but in the Philippines two-thirds obtained
two crops per year. Although most of these questions
were not asked in Rwanda, scarce inputs and cooler
water may slow fish growth and lengthen the crop cycle
to eight months or more. Warmer water, the stocking
of larger fingerlings, or the harvest of a smaller fish
may have allowed more than a quarter of the farmers
in the Honduras sample to report growing tilapia in
less than 180 days.
Polyculture, or raising more than one species
of fish in the same pond, was practiced by nearly all
the Thai farmers in the study. A third of the Honduran
farmers reported stocking other species, but only 11%
of the Philippine farmers did so. Although the question
was not asked, polyculture generally is not practiced
TABLE 6.7. FINGERLING SOURCES, TILAPIA FARMS IN FOUR PD/A
CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct. Pct. Pct.
Where do you obtain tilapia fingerlings?
Govt. hatchery - 57 40 4
Research station - 18 0 0
Hatchery/station - 6 0 0
Private dealer - 2 37 82
From a neighbor - 2 7 9
From own ponds - 16 9 9
Type fingerlings used?
Natural colored - 63 7 100
Red colored - 6 0 0
Other (black & red) - 31 93 0
Tilapia species used?
Niloticus - 100 96 100
Mossambicus - 0 0 0
Aureus - 0 2 0
Hybrids - 0 2 0
Stock all-male or mixed-sex tilapia?
Mixed-sex 100 4 0 0
All-male 0 88 93 100
Both 0 8 7 0
What method produced all-male fingerlings?
Hybridization - 2 11 2
Sex reversal - 76 78 10
Hand-sexing - 20 11 2
Some combination - 2 0 2
Don't know - 0 0 84
(Number) (136) (51) (50) (56)
in Rwanda. In Honduras and Thailand,
the additional stocked species tended to
be a predator fish such as Guapote tigre
or snakehead, respectively.
Philippine farmers were least likely to
use a predator fish. Although not
reflected in the survey data, this practice
is not yet in use in Rwanda. The presence
of a predator eliminates small fish and
reduces the impact of unwanted tilapia
reproduction on a crop of fish. The
predator species generally is not viewed
as another crop or enterprise, given the
relatively small number that are stocked.
Small tilapia are undesirable because they
compete for feed with the market-size
part of the crop. Fingerling availability
was a problem for 30% of the Philippine
respondents, 24% in Rwanda, 22% in
Honduras, and a concern for only 4% in
Thailand.
WATER MANAGEMENT
Table 6.9 shows how fish farmers use
and move water. To maintain the quality
of water in farm ponds, farmers often add
additional water or use an aerator to
provide additional oxygen to the fish. The
most immediate symptom that causes
farmers to intervene is piping fish
[surfacing to draw oxygen-rich water into
their mouths], and in extreme cases, dead fish. Some
ponds with large populations of intensively-managed
large fish also may require additional water to dilute
excessive amounts of fish waste.
Exchanging water was the most frequently
used water quality management strategy. It was used
by all the Thai farmers, more than half the Philippine
farmers, and about a quarter of the Honduran farmers.
When asked how frequently they exchanged water,
about 80% of the Honduran farmers said they never
exchange water, suggesting that they understand the
procedure but rarely are required to use it, or do not
have enough water to do so. About 37% of the
Philippine respondents said they never exchange water.
We asked farmers to report the presence or absence of
various types of equipment on their farms. Honduran
farmers were most likely to have a vehicle. Philippine
farmers were most likely to have a net, but more Thai
farmers had a water pump and a scale.
29
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
TABLE 6.8. STOCKING AND GROW-OUT PRACTICES, TILAPIA FARMS IN
FOUR PD/A CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct. Pct. Pct.
How many crops each year from each pond?
One - 54 25 95
Two - 40 66 5
Three or more - 6 9 0
How long does tilapia crop grow?
< 180 days - 50 94 10
180 to 240 days - 14 6 6
More than 240 - 36 0 84
Raise other species of fish with tilapia?
Yes - 36 11 98
No - 64 89 2
Stock a predator species?
No - 6 71 2
Yes - 94 29 98
Problems finding fingerlings for restocking?
No 76 78 70 96
Yes 24 22 30 4
Usual stocking density?
Less than 1/m
2  
- 13 13 0
1/m
2 
or more - 87 87 91
How large are the fingerlings stocked?
Less than 3 cm. - 46 70 86
3 to 5 cm. - 40 16 14
5 to 10cm. - 12 5 0
More than 10 cm. - 2 0 0
Mixed sizes - 0 9 0
(Number) (136) (51) (50) (56)
TABLE 6.9. WATER MANAGEMENT STRATEGIES, TILAPIA FARMS IN
FOUR PD/A CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct. Pct. Pct.
Use an aerator or exchange water?
Exchange water - 24 59 100
Use an aerator - 0 0 0
Use both - 0 0 0
Use neither - 76 41 0
How often do you exchange water?
Never exchange - 80 38 2
Every day - 8 7 2
Almost every day - 2 2 2
Several a week - 4 2 4
Once a week - 2 4 16
Several a month - 4 47 74
or as needed
What equipment do you have on your farm?
Truck - 71 16 56
Harvest net - 71 84 38
Water test kit - 4 0 6
Water pump - 18 75 98
Aerator - 2 2 0
Oxygen meter - 2 2 0
Scale - 90 26 100
Wheel barrow - 0 0 22
(Number) 
(136) (51) 
(50) (56)
HARVEST PRACTICES
Farm labor for harvesting fish was
usually supplied by family members in
the Philippines, as shown in Table 6.10.
Partial harvesting - taking only the fish
necessary for a day's consumption, to fill
an order, to provide a certain amount of
cash, or to provide a day's worth of fish
for the market - was more common in
Rwanda, Honduras, and the Philippines.
More than two-thirds of the Philippine
respondents said they usually partial
harvest their ponds.
Some farmers may partial harvest to
select only larger fish, to harvest only a
quantity that can be marketed with
certainty, or to avoid cash outlays for the
labor that might otherwise be required for
a complete harvest. Thai farmers tended
to harvest the fish all at one time. In
Honduras and Thailand, harvest labor
was typically accomplished by paid
workers engaged either by the farmer or
the buyer. In Thailand, buyers frequently
harvest the fish they purchase from
farmers as part of the marketing
transaction. Family labor did the work in
about a quarter of the Honduras
situations.
In Rwanda, around half the ponds are
group ponds. Previous work shows that
members of the group or their family
members supply the labor at harvest time
(44). Some private farmers hire laborers
or organize neighbors to work for a share
of the harvest when it is time to drain the
pond. About two-thirds of the Rwandans
reported one large harvest, where
cooperative labor arrangements usually
are made.
In Rwanda, we estimate that about
80% of the harvested tilapia weigh less
than 120 grams. Lack of nutrient inputs
tend to lengthen the time necessary to
grow larger fish.
Farmers tended to harvest larger fish
in Honduras, as more than two-thirds
reported harvesting fish larger than 250
grams. The Philippine operators had a
similar harvest size preference, though a
few more harvested smaller fish. In
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
TABLE 6.10. HARVEST 
PRACTICES, TILAPIA FARMSINthan 
half the harvest for cash. 
Only 40% of the
FOUR PD/A CRSP COUNTRIES, 
1994 Rwanda 
respondents sold for cash. Previous
research suggests that much of the fish in
Rwanda Honduras Philippines Thailand Rwanda was used for home consumption or
Pct. Pct. Pct. Pct. bartered 
for harvest labor. In Honduras, 80%
Did you hire labor to harvest tilapia? said they sold more than half for cash. Nearly
No, self - 6 9 0 100% did so in the Philippines and Thailand.
No, family - 29 91 8
Yes, laborers - 65 0 28 Middlemen purchased fish from all the
Buyer harvested - 0 0 64 Thai farmers, three-fourths of the Philippine
Had trouble getting enough labor to harvest your pond? farmers, almost half the Hondurans, but nearly
No labor used - 26 66 9 none of the Rwandans. Farmers that sold
No, no problems - 66 28 89 tilapia to restaurants were more frequent in
Yes, difficulty - 8 6 2 Honduras. Direct marketing was more
Usually partial harvest or have one large harvest? common in the Philippines, where 30%
Usually partial 36 37 69 6 reported selling fish in the market. The most
Partial & a large 0 22 21 17 common marketing method for farmers in all
A single harvest 64 41 10 7 countries was pond bank sales to neighbors
Average size of tilapia harvested? and others coming to the ponds at harvest.
Less 120 grams - 4 13 6 Word-of-mouth knowledge about prospective
120 to 249 grams - 18 49 26 harvests or the willingness to partial harvest
250 to 499 grams - 35 27 33
500 to 749 grams 
- 29 
11 27 
for immediate sale 
remain primary 
means for
More 750 grams 
- 14 
0 8 
marketing tilapia 
for most small 
and medium
(Number) (136) (51) (50) 
(56) size farmers.
Thailand, however, 
more than half 
the sample 
MARKETING PROBLEMS
harvested fish less than 250 
grams in size. 
More than two-thirds of 
the respondents said -
31
MARKETING TABLE 6.11. MARKETING PRACTICES, TILAPIA FARMS IN
Marketing of tilapia at a profitable FOUR PD/A CRSP COUNTRIES, 1994
margin is affected by many factors, most beyond Rwanda Honduras Philippines Thailand
the control of the individual fish producer.
Consumer preference for certain fish species, Pct. Pct. Pct. Pct.
sizes and product forms will 
determine what Any cash 
for last harvest?
sells. Research into 
existing marketing channels 
No 
60 13 
2 0
Yes 40 87 98 100
provides a starting point from which to develop How much sold for cash?
alternative outlets. None for cash 7 6 4 0
Less than half 33 92 20 0
Tilapia culture has been successful in Half for cash 12 2 76 4
many places, but markets often have not been 
More than half 48 0 0 
96
properly developed in tandem with increases in Did middleman buy any?
supply. While production is low, family and No 98 51 21 0
neighbors can consume the product, but as Ys oeo t 24 33
production increases, outlets for new supplies of Ys l fi 66
fish must be more methodically established. Sell any to restaurants?
No 98 71 92 98
Results from this study give a view as to what Yes, some of it 2 29 8 2
channels are presently being used by tilapia Yes, all of it 0 0 0 0
farmers. Sold any in the market?
No 86 92 70 93
Only a small proportion of each sample Yes, some of it 13 8 19 5
reported fish harvested solely for home Yes, all of it 1 0 11 2
consumption or barter, i.e., none sold 
for cash, Anyone else sold tilapia?
Table 6.11. Most sold some fish for cash, though No 58 18 26 41
a Pond bank sales 42 82 74 59
a third of the Rwandans said that they sold less (Number) (136) (51) (50) (56)
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Pct.
100
0
Pct.
69
31
50
50
TABLE 6.12. MARKETING PROBLEMS, TILAPIA FARMS IN
FOUR PD/A CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct.
Did you have trouble selling your tilapia?
No 79 82
Yes 21 18
Had problems selling at price you want?
No 77 90 100 44
Yes 23 10 0 56
Even if you cannot get the price wanted, can you usually sell
at a lower price?
No 27 36 76
Yes 13 64 24
Some people in area do not like to eat tilapia?
No 66 84 100
Yes 72 42 85
Larger tilapia would be easier to sell?
Sold fingerlings to other farmers?
No 49 84 74
Yes 51 16 26
Did you have trouble selling fingerlings?
No, did not sell 42 84 70
Had no problems 31 16 30
Yes, problems 27 0 0
(Number) (136) (51) (50)
85
96
4
96
94
6
94
4
2
(56)
32 they had no problem marketing tilapia, Table 6.12.
There was concern in Thailand by the farmers that they
were not getting the price they wanted. Many also
responded that they could not sell their fish even when
they lowered their prices. Similar comments were also
made by Philippine and Honduran tilapia farmers.
In a study of people practicing aquaculture in
Rwanda, Molnar found that fish were considered a
recent entry into traditional diets, except in some lake
areas (43). No cultural taboos toward eating fish were
discovered, although knowledge of fish preparation
methods was limited. Consumers exhibited a clear size
preference for marketed tilapia. Fish greater than 120
grams sold quickly at $2.00/kg, but fish weighing less
than 100 grams would not be purchased, even at
reduced prices. However, this size bias changed by
region, with consumers in some lake regions accepting
smaller fish. A 120-gram fish was attainable in 7 to 9
months by farmers that followed recommended
management practices.
Philippine farmers indicated no trotible
marketing their fish. Marketing difficulties of some kind
were reported by about a third of the Thai respondents,
and around 20% of the Honduran and Rwandan
respondents. Over half the Thai farmers reported
difficulties securing the price they wanted for
their tilapia. Honduran farmers were the most
confident about being able to sell their tilapia at
some price, even if it was not what they originally
offered.
Three-quarters of the farmers in the present
study felt a larger fish would be easier to sell. In
Thailand and the Philippines, almost 100% of the
respondents felt larger fish would sell more
easily. In Honduras, approximately half the
operators with small and medium-sized ponds
and 82% of the larger pond operators felt a larger
fish would sell more easily.
About a third of the Rwanda sample said that
there were many people in their area that did
not like tilapia. Around 15% of the Honduras and
Thai respondents felt this way, but no Philippine
respondent said so. Of the four countries, the
Philippines seems to have the highest consumer
acceptance of tilapia.
Fingerling sales to other farmers were most
common in Rwanda, where more than half the
respondents reported such transactions. Private
fingerling sales among farmers is an important
indicator of sustainability, especially where government
services are unreliable or unavailable in much of the
country.
Fingerling sales between farmers were least
common in Thailand, 6%, largely because a network of
private dealers is well-developed there. Dealers are less
common in Honduras, but a small segment reported
fingerling sales (16%) as did a few more in the
Philippines (26%). Rwandan farmers apparently were
most actively seeking to sell fingerlings - largely
because the mixed-sex production strategy they
employed yields many small fish due to unwanted
reproduction. About half sold fingerlings, but about
half of the fingerling sellers reported problems in
making the sales they wanted. None of the respondents
in other countries reported problems selling fingerlings.
IMPACTS ON HOUSEHOLDS
Table 6.13 shows a series of questions profiling
the impacts of fish culture on households. About 78%
of the Philippine farmers thought that there were points
in the annual farm cycle when the pond was too much
work, 37% in Thailand. Few of the other respondents
thought so. Previous work suggests that Rwandan
women are much more likely to report these difficulties
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
TABLE 6.13. FISH POND IMPACTS ON HOUSEHOLDS, TILAPI
FARMS IN FOUR PD/A CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct. Pct. Pct.
Are there times when the pond is too much work?
No 98 78 22 63
Yes 2 22 78 37
Does tilapia fit well with other activities of household?
No 17 36 9 21
Yes 83 64 91 79
Does tilapia pond make it harder to care for other crops?
No 94 92 100 94
Yes 6 8 0 6
Does having a pond make it harder to take care of family?
No 95 94 100 91
Yes 5 6 0 9
Does pond make it harder to complete other household wor
No 94 90 98 92
Yes 6 10 2 8
Does the cash from tilapia make it easier to buy things for yo
family?
No 95 27 14 8
Yes 5 73 82 92
(Number) (136) (51) (50) (56)
but only 64% of the Honduran farmers thought so. They
also were slightly more likely to report problems
completing household work or taking care of their
family.
Few respondents noted problems associated
with the tilapia enterprise in taking care of other crops,
taking care of the family, or completing other household
work. Three-quarters or more of the respondents in the
Philippines, Honduras, and Thailand noted the benefits
of additional cash for their households as something
associated with the tilapia crop. Only 5% of the
Rwandans agreed with this statement. The limited
amount of cash produced by tilapia in Rwanda is used
mainly by men to purchase beer or rent more land.
POND CONFLICTS
Table 6.14 shows respondent experiences with
a series of problems sometimes encountered by tilapia
farmers. Thai farmers were most likely to note
problems over water resources emanating from the
tilapia crop (57%), an issue noted by only a few of the
other respondents. Philippine operators had few
problems with predators eating their fish, but this was
an issue for farmers in each of the other countries.
Theft was a concern for 44% of the Honduran
farmers, but only 20% or so of the Rwanda and
Thailand respondents noted this as an issue; only 11%
did so in the Philippines. Thai farmers were most
likely to agree that tilapia were easier to steal,
A though a third 
of the Honduran respondents
thought so as well.
PROSPECTS FOR THE POND
Most respondents thought their fish pond
produced enough to be worth the work they put
into it, though Rwandans were slightly more
skeptical (Table 6.15). A third of the Hondurans
questioned the fit of tilapia with the other
activities of their farm household. About 60% of
the Hondurans thought that tilapia was less
profitable than their other activities.
Most respondents thought tilapia was the best
use of the land it occupied. Hondurans were more
k? likely to report themselves as 
planning to build
new ponds (39%). In land-short Rwanda only 11%
thought so.
ur
Only 54% of the Rwandans were happy with
tilapia as a type of fish to grow; they desired a
larger, faster growing fish. More than 90% of
respondents in the other nations were happy with
tilapia as a type of fish to grow.
The perceived profitability of tilapia relative to
other farm activities was highest in the Philippines,
where 90% thought it was more profitable than other
crops. About 78% thought so in Thailand. In Honduras,
23% thought it was more profitable.
Overall Hondurans were least happy with the
profitability of tilapia, though Thai farmers were less
convinced that tilapia ponds were the best use of the
TABLE 6.14. POND CONFLICTS, TILAPIA FARMS IN
FOUR PD/A CRSP COUNTRIES, 1994
Rwanda Honduras Philippines Thailand
Pct. Pct. Pct. Pct.
Conflicts with others over water for ponds?
No - 94 100 43
Yes - 6 0 57
Birds or other animals eating tilapia from ponds?
No 31 24 95 4
Yes 69 76 5 96
Problems with people stealing tilapia from your pond?
No 78 56 89 81
Yes 22 44 11 19
Are tilapia easier to steal than crops?
No 97 62 80 55
Yes 3 38 20 45
(Number) (136) (51) (50) (56)
33
r , ~-
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
personnel turnover, contributed 
to the low
TABLE 6.15. PROSPECTS FOR THE FISH POND, TILAPIA FARMS IN impact of extension in that country. A third
impact of extension 
in that country. A 
third
FOUR PD/A CRSP 
COUNTRIES, 1994 
indicated no contact 
with extension 
in Honduras.
Rwanda Honduras Philippines 
Thailand More contacts were noted 
with Honduran fish
Pct. Pct. Pct. Pct. stations that supply fingerlings 
and some
Does tilapia produce enough to be worth the work 
put into it? technical assistance to farmers. In 
Honduras,
YeNo 28 8 7 10 Peace Corps has been very active in fish culture,
Yes 72 92 93 90
as has the staff of the Pan-American Agricultural
Is tilapia pond the best use of land it uses on the farm?
No 11 12 0 24 School (Zamorano). Honduras was the only
Yes 89 88 100 76 country where Peace Corps contacts were
Are you planning to build more ponds? reported. About a third of the Honduran and
No 89 
61 2 71 
Thai farmers had no extension contact. 
Most Thai
Yes 11 39 98 29 and 
Philippine 
farmers 
wanted 
extension 
help
Generally happy with tilapia as a fish to raise?
No 46 6 2 6 in the future, but farmers in Rwanda and
Yes 54 94 98 94 Honduras were not certain.
How profitable is tilapia compared to other activities?
More profitable - 23 90 78 Farmers were 
asked about the main things
About the same -6 17 8 8 preventing larger harvests. Water quality was the
(Number) (136) (51) 
(50) (56) biggest issue 
in Thailand and the Philippines,
referred to simply as "the pond" in Rwanda.
Manure and compost availability was the
land. Lowland Thai farmers with irrigation in the 
far obstacle most frequently cited in Rwanda. Honduran
reaches of the Bangkok marketing area have many farmers noted "my understanding" as the major
enterprise choices and marketing opportunities. 
obstacle to obtaining larger harvests from their 
ponds.
TECHNICAL ASSISTANCE TABLE 6.16. 
SOURCES OF TECHNICAL ASSISTANCE, TILAPIA FARMS 
IN
34 Aquacultural extension services FOUR PD/A CRSP COUNTRIES, 1994
were making frequent contacts with
farmers in Rwanda, but not the other
nations. In Rwanda, a well-trained 
cadre 
Pet. Pct. 
Pct. Pct.
Last extension contact?
of extension personnel were supported by 
Never contacted 6 35 
22 35
donor funds. Most farmers received In past months 75 26 46 50
regular visits if they wanted them. 
The Months to year 
6 10 14 
4
Rwandan respondents 
also were More 
than a year 13 
29 18 
11
Last fish station contact?
somewhat more likely to report some Never contacted 
- 4 25 62
type of extension contact in the past. Only In past months - 38 43 17
10% wanted additional extension help. 
Months to year - 22 
14 6
A highly professional, 
relatively More than 
a year 
36 18 
15
well-organized extension 
and research Peace Crops 
contact?
No - 16 100 100
system is in place in Thailand. Yes - 84 0 0
Nonetheless, about a third of the Thai University staff contact?
respondents indicated that they never No - 80 28 75
have had contact with an extension 
Yes -
20 72 25
representative. Budget problems limited Want more extension help?
on-farm extension work to a small set of No 90 0 2 17
individuals supported 
solely by Yes 
10 100 98 
83
provincial-level government 
in the Main obstacles to larger 
harvests?
The species 45 11 0 0
Philippines. Most farmers wanted more No inputs 59 9 0 0
extension help. Water too cold 9 2 0 0
hep.My understanding 2 36 0 0
Water quality 0 0 95 40
In Honduras, high inflation has Pond leaks 0 5 0 0
degraded salaries, travel budgets, and Kind of inputs 0 23 0 0
morale for extension personnel. 
These No extension 
0 5 0 
0
Other 2 9 5 60
conditions, coupled with high levels of (Number) (136) (51) (50) (56)
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
CHAPTER SEVEN
SURVEY RESULTS: DIFFERENCES
BY FARM SIZE
INTRODUCTION
This chapter elaborates the survey data by
portraying production systems, technologies, and
farmer perceptions of selected fish culture issues as they
vary by farm size. Pond area has a close correspondence
to subsistence, small-scale and commercial levels of
aquaculture production (32). Distinguishing these
production levels are nutrient types, nutrient quantities,
water manipulation, and fingerling-related decisions.
Social and economic aspects of aquacultural systems
determine their sustainability and long term
profitability. Therefore, a holistic view of these farmer
characterizations are needed and to separate them
completely belies their true interconnectedness and
interdependence.
From the economic side, producer incentives
involve the efficient use of land, labor and capital. From
the social side, the size of the farm pond operation
reveals much about the farmer's situation and
capabilities. This analysis addresses each issue from a
small, medium and large pond owners point of view
for each study country. Attention is also given to specific
variable inputs, output prices, marketing occurrences,
and some obstacles to raising tilapia.
Tilapia production technology varies with
intensity, market availability of inputs, capital, land and
owner's degree of risk aversion. Technological change
involves knowledge of aquacultural principles and the
desire to increase production efficiency through
innovation and adoption of new sustainable
technologies. Increasing fish
production by improving the
quantity and quality of nutrientTABLE.
inputs has many associated
implications on management, labor
and capital. Additionally, there are
social contexts that will affect Size Category
technology adoption rates.
Small
Farm pond area is Medium
examined using three categories - Large
small, medium and large- Range
depending on the range reported in 
1 
Rwanda data w
pond area was n
each country. Table 7.1 shows how the cases in each
sample were divided into thirds - according to pond
area - to obtain small, medium and large pond area
categories. The classification boundaries are not the
same for each country.
The small pond area grouping is less than or
equal to 0.11, 0.65, and0 .96 hectares in Honduras, the
Philippines, and Thailand, respectively. The medium
pond area groupings are 0.12 to 0.65, 0.66 to 3.0, and
0.97 to 1.76 hectares, respectively. The large pond area
groupings are greater than 0.65, 3.0, and 1.76 hectares
in Honduras, the Philippines, and Thailand,
respectively.
The categories correspond well with
production intensity levels and allow cross-country and
intra-country pond area comparisons. Rwanda data has
been included in the 'small' pond area category because
of its homogeneous low-intensity type of tilapia
production, regardless of actual pond area.
FARMER PERCEPTIONS OF TILAPIA CULTURE
Regardless of farm size, most fish farmers in
Rwanda, Thailand, Philippines and Honduras felt that
the tilapia pond was the best use of the land it occupied
on their farm, Figure 7.1. This question was intended
to elicit the farmer's assessment of the aquaculture
enterprise as compared to other possible activities that
could take place on the ground the pond occupies.
Fewer farmers in the medium and large pond area
categories in Thailand felt tilapia production was the
CLASSIFICATION OF TILAPIA FARMS BY POND AREA IN
FOUR PD/A CRSP COUNTRIES, 1994.
Total Farm Pond Area by Country
Rwanda' Honduras Philippines Thailand
Ha. Ha. Ha. Ha.
- 0.11 0.65 0.96
- 0.12 - 0.65 0.66 - 3.0 0.97 - 1.76
- >0.65 >3.0 >1.76
0.01 - 0.10 0.08 - 16.32 0.05 - 100.0 0.005 - 15.2
ere collected prior to this study and categorization by total
)t possible.
35
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
best use of their land, although the percentage was still
Percent Tilapia best use 
over 60%. As the Thailand respondent's 
pond area
increased, a smaller percentage replied that the pond
was the best use of the land occupied. All Philippine
owners, regardless of pond category, agreed
100 
aquaculture 
was the best 
use of the land.
90 When asked to compare profitability of tilapia
80 .farming to other farm activities, the most contradictory
70 
patterns were observed in the answers given by 
farmers
in Honduras, Figure 7.2. Only 8% of the small pond
60 owners 
ranked fish culture as the highest cash
50 
producing enterprise while 32% 
of the medium and
40 
36% of large pond 
operators ranked 
the fish as the
highest cash-producing enterprise.
30
Thailand
20ilippines 
Farmers seem to be indicating that aquaculture
10 
Honduras was 
less profitable than 
other farm activities 
after
Sm0 a 
Rwanda saying that 
the pond was the best use 
of the land on
Small Medium Large 
their farm. This seeming incongruity 
of the two
responses may be explained by the location 
of pond(s)
on marginal agricultural land. If this is the case, though
aquaculture is not as profitable as other farm activities,
Figure 7.1. Percent agreeing that Tilapia pond is best use of it is still a 
better use of the land because little other
the land it occupies on the farm by pond 
holding size, and agricultural activity 
could occur on the parcel.
country, Tilapia farmers, 1994-95.
All pond size owners in the Philippines felt
Percent Tilapia more profitable 
very positive about aquaculture in relation 
to other farm
activities, Figure 7.3. In Thailand, small and medium
pond size owners shared a similar high degree of
enthusiasm about tilapia culture, but only about half
100 
the large farm operators in Thailand agreed 
that tilapia
90 
was more 
profitable than 
other farm 
activities.
80 Appendix I shows the farm enterprises that
70 
provide the most cash income. 
High percentages of
60 
Philippine and 
Thai farmers 
rank fish culture 
as the
single most positive farm enterprise. These same
50 farmers also tend to have highly diversified operations,
40 
often an effective way 
to reduce agriculture production
risks. The diversification of farms decreases as the farm
30 pond area increases, indicating larger degrees of
20 Thailand specialization in fish culture, rice production and/or
10 
. Philippines livestock 
production as size increases.
0 Small .Medium Labor. The amount of labor required for an
aquacultural enterprise varies with the technology
Size of pond holdings employed. The use of animal manures, green manures,
and other on-farm by-products often involves a
Figure 7.2. Percent indicating that growing Tilapia is more significant labor expenditure for collection, transport
profitable that other farm activities by pond holding size, and and application. 
Labor used for joint livestock-fish or
country, Tilapia farmers, 1994-95.
36
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Percent visiting daily or more often
All Mdu ag
100
........po...h......
90
80
70
60
50
40
30 a 
Tiln
20 Philippines
10 ......n.t..esy t Honduras
10
Small Medium Large
Size of pond holdings
Figure 7.3. Percent visiting ponds daily or more often by pond
holding size, and country, Tilapia farmers, 1994-95.
fish-crop activities in integrated systems, such as
feeding, weeding, and by-product re-use, increases
labor efficiency both overall and for the enterprise.
Labor can be a cash or non-cash cost. Labor
activities required in the production cycle are often non-
cash costs, i.e., many farms in developing countries use
available family labor only or work collectively at
certain periods of the year such as at harvest time. The
intensity of production and available resources will
determine the farmer's need for additional labor. Often
farmers who employ laborers are more tied into market
economies and exhibit higher degrees of managerial
ability that may lead to acceptance of technological
innovations more readily than strictly on-farm
operators.
The frequency of pond visitation has been used
as an indication of good pond management. This
linkage assumes most pond visits accomplish some
nutrient input for the fish. Nutrient systems using
vegetation or animal manures require frequent
application of inputs to maintain plankton communities
in the ponds. When farmers are providing feed, tilapia
respond better to many small feedings versus one large
feeding.
If this linkage is indeed true across locations,
then, as a whole, Thai farmers manage their ponds
better than farmers in the other countries, Figure 7.3.
In Honduras, as the pond area increased, more visits
were made per day. In Rwanda, and for the large pond
owners in the Philippines, only about half the farmers
visited the pond at least once a day.
However, visitations alone may not be the only
factor promoting good tilapia production. The length
of stay may also be relevant. On average, the Philippine
farmers spent more than three hours per visit to the
ponds. Thai farmers did not fare well as they averaged
under an hour per visit.
In Honduras, more time was spent per visit as
the pond area increased. Small pond owners spent
about an hour per visit, while medium pond owners
spent about two hours and large pond owners spent
more than three hours per visit. Most Rwanda farmers
spent about one hour per visit.
In the Philippines and Honduras, most used a
mix of family labor and hired labor. Operation owners,
additional family members and hired laborers were
employed to help harvest tilapia. Results suggest that
as pond area increased more laborers were hired, with
less reliance solely on family labor.
The availability of labor to be hired by the fish
farmers was a problem only in Thailand, for all size
categories. In Honduras, difficulty in obtaining labor
increased with pond area. It is not clear if a scarcity of
skilled labor or simply few laborers in the pond locale
created this problem.
Capital. The number of ponds and pond area
were used to reflect capital investment. These analyses
are shown in Tables 7.2 and 7.3, along with equipment
used in the aquaculture operation, Appendix II.
Information on the total pond area (for each
size category), number of ponds per farm and average
pond area for the three PD/A CRSP countries are found
in Table 7.2. In general, Thailand had fewer ponds per
farm than did farmers in the Philippines and Honduras.
Also, the average pond area was larger in Thailand than
in the other two countries.
Most of the farmers in the small pond area
category had two to three ponds in all countries, Table
37
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
TABLE 7.2. AVERAGE TOTAL POND SURFACE AREA, AVERA
OF FISH PONDS, AND AVERAGE POND AREA BY SIZE CA
IN HONDURAS, THE PHILIPPINES, AND THAILAND, 1
Country and Average Total Average Number A
Size Category Pond Area of Ponds
Ha. No.
Honduras
Small 0.05 2.8
Medium 0.35 3.6
Large 4.01 12.5
Philippines
Small 0.30 2.2
Medium 1.75 5.5
Large 12.47 11.0
Thailand
Small 0.48 1.6
Medium 1.43 1.8
Large 6.09 5.0
TABLE 7.3. TOTAL OWNED FARM AREA, OWNED AND
POND AREA, AND POND AREA AS PROPORTION OF OWN
IN HONDURAS, THE PHILIPPINES, AND THAILAND, 1
Country and Avg. total Avg. pond P
size category owned farm area owned and
area leased o
Ha. Ha.
Honduras
Small 128.10 0.05
Medium 81.09 0.35
Large 383.74 4.01
Philippines
Small 1.63 0.30
Medium 5.23 1.75
Large 4.11 12.47
Thailand
Small 3.07 0.48
Medium 4.29 1.43
Large 3.62 6.09
7.3. The same was true for medium-sized farm in
Thailand. In the Philippines and Honduras, more
medium-sized farms had between three and six ponds,
and large farms had between 11 and 13 ponds.
Farm size differences in patterns of equipment
usage in the aquaculture operation are available in
Appendix II. Overall, it seems that Honduran tilapia
operations were more capital (equipment) intensive
than were the Philippine and Thai operations. However,
in the Philippines and Thailand, water pumps were
used by most aquaculturists due to the water delivery
system available. The relative absence of seine nets on
Thai fish farms is understandable because of their
GENUMBER preference for one 
large fish harvest
TEGORY rather 
than partial harvesting 
preferred
994. in the Philippines 
and Honduras,
where seine nets were more commonly
Average 
Pond
Sierfound. Custom harvesting also is a
Size
service generally more available to
Ha. Thai producers.
0.02
0.10 The greater use of water pumps by
0.32 farmers of all sizes in the Philippines
and in Thailand than in Honduras is
0.14 largely because of the topography of
0.32 the study area. Additionally, the use of
1.13 water pumps may indicate a 
greater
number of users of the same water
0.30 system for agriculture than in the
0.79 Honduran agriculture system. The
1.221.22 topography 
of Thailand is 
flat and
water is pumped to fill and/or drain
LEASED
LEASED 
ponds. The Honduran 
topography
ED LAND
994. 
permits gravity 
filling and draining.
Water resources will be discussed at
ond area as greater length 
in a following section.
pct. of
wned landwned land Common 
to all study countries 
was the
Pct. lack of any widespread usage of water
0.1 
quality kits, 
aeration equipment 
and
0.1
0.4 dissolved 
oxygen meters. These 
items
0.4
1.1 are indicative 
of capital intensive fish
culture operations and higher
18.7 
production intensity, 
indicating that 
in
33.4 these three 
countries tilapia culture 
is
303.7 occurring at less intensive production
levels. Another interpretation of the
15.7 answers to the question regarding
33.2 equipment would be that these items
168.2 are not available, their cost 
is high, or
farmers lack knowledge of the use and
interpretation of results provided by these instruments.
Less-intensive production levels also are less risky for
the producer regardless of size.
Land. Ponds are specialized structures whose
use is limited to aquaculture. Ponds physically alter the
land to a greater degree than do crop, livestock, and
poultry activities. (One exception is the modification
of rice fields for rice-fish culture). However, ponds can
be situated to exploit unique topographic and physical
characteristics, as well as making marginal agricultural
land productive.
In each country, there was an increasing
38
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
percentage of land put into ponds as the total farm area
increased, Table 7.2. This seems to indicate that smaller
land owners were less likely to invest or risk their land
in fish culture. This would mean having less land
available for other agricultural activities. Smaller farms
may depend on non-pond land for subsistence food
security while larger farms would have the household
food security covered through the larger farm area
available or through cash purchases in the market place
and could therefore devote more land to other
enterprises.
In Honduras, farmers were less likely to put
their land into ponds than in the Philippines or in
Thailand, as evidenced by the area of ponds as a percent
of total farm land owned. Whatever pond area category,
Philippine farmers put greater percentages of their land
into aquaculture, Table 7.2.
Water. Aquaculture requires that water be
available in sufficient quantity year round, or at least
for the duration of the production cycle. Dry seasons
can be favorable for aquaculture in terms of
temperature and photosynthetic activity, but
unfavorable in terms of water availability to replace
water lost to evaporation and seepage.
Adequate water quality and quantity and
control of pond water levels are essential to
aquaculture. Because aquaculture tends to require
greater quantities of water than other agricultural
activities, the cost of water-source development
often will be greater 
than for other agricultural 
C(
uses. The control of the water resource 
may not si
only yield substantial benefits for the aquacultural
activity, but also may improve production Ri
performance of other crops such as rice and
vegetables. H
Control of pond water levels is important
in water quality maintenance and stock
management. Water inlets and outlets must permit P1
the controlled addition and removal of water.
Additions of water to ponds are needed to replace
seepage and evaporation losses or to improve
deteriorated water quality. Ponds are drained to T
simplify complete harvest of the stocked fish.
Proper pond design allows all water to drain from
the pond by gravity. Pond water level control
structures range from simple to sophisticated. 1
Tilapia growers in Thailand seem to have
the most problems obtaining water, Table 7.4. Further
details of water sources by farm size are specified in
Appendix III.
About 71% of the Thai small farm operators
reported problems getting enough water to keep their
ponds filled. The percent of farmers reporting water
procurement problems in Rwanda was 24%, while the
range for Philippine farmers was 25-50%. In the
Philippines, problems obtaining water generally
decreased with pond area. In contrast, the number of
Honduran farmers having difficulty in getting enough
water ranged between 13-24%.
No major farm-size differences were noted in
water source. The main water source for Thai tilapia
farmers was agricultural irrigation canals. Aquaculture
requires more water at certain times of the year,
increasing chances for conflict over water with other
agricultural water users. Over 70% of the small and
large size Thai farmers responded that they had
conflicts with other farmers over the use of water for
their fish ponds. Few, if any, such conflicts were
reported by Filipino and Honduran respondents.
Less irrigation water was used in the
Philippines than in Thailand and no irrigation water
TABLE 7.4. WATER AVAILABILITY AND SOURCES
FOR AQUACULTURE IN RWANDA, HONDURAS,
THE PHILIPPINES, AND THAILAND, 1994.
Farmers having
ountry and problems getting Primary water source
ze category water'
Pct.
wanda
Small 24 Stream or Spring
onduras
Small 18 Stream or Spring
Medium 24 Stream, Spring or Lake
Large 13 Above Plus Well
hilippines
Small 50 Combination
2
Medium 25 Combination
2
Large 27 Combination
2
hailand
Small 71 Irrigation Canal
Medium 50 Irrigation Canal
Large 41 Irrigation Canal
Response to the question, "Have you had problems getting
tough water to keep your pond filled?"
Combination water sources for the Philippines included
Illected runoff, well, stream, and irrigation canal water.
39
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
was used in Honduras, Table 7.4. The main water
sources for tilapia farmers in Honduras were either
rivers/streams, springs or some combination thereof.
The diversity of water sources available to Philippine
and Honduran farmers probably reduced potential
water use conflicts with other agricultural water users.
Water quality is a serious concern for farmers
regardless of size. Insecticide and herbicide residues
and accumulationsfrom nearby agricultural operations
may adversely affect fish health. Thai tilapia farmers
reported poor water quality from pollution as a
problem in raising fish. Approximately 33% of the small
and medium-size farmers - and 50% of the larger farm
operators - reported pollution problems.
Pollution problems stem from the multiple
users of the irrigation canal water and the return of
waste water to the canals. This is an externality that
downstream water users have little control over, and
they usually must accept the consequences without any
recourse. Conversely, the percentage of Philippine
farmers having water pollution problems decreased
with increasing pond area; 11% with small pond area,
6% at the medium size, and none of the large farmers.
It is not coincidental that the Thai farmers who
are likely to operate at semi-intensive or higher
production levels had the most problems with water
quality. The higher the production intensity the greater
the need for additional water to flush wastes out of the
pond. Water quality in Thailand is a serious problem
with many water users requiring differing quantities
and quality of water. Conversely, farmers in the
Philippines and Honduras had fewer water quality
problems.
Inputs. Aquacultural 
production 
TAB
IN
cycle length is dependent on a variety of
factors and their interactions. 
These Country an
include; climate, 
pond area, nutrient 
size categc
input quality and quantity, stocking Honduras
density, water quality, species choice, size Small
of stocked fingerlings, disease and Medium
mortality incidence, and size of fish Large
wanted at harvest (32). Philippine
Small
Medium
Techniques used to decrease time Large
required to obtain market-size fish are Thailand
based on the application of the principles Small
of aquaculture. The economics 
of Medium
aquacultural 
production 
centers 
on the[Large
variable inputs. Nutrient inputs and fingerlings are the
dominant variable cost items. It is the efficient and
marginal combination of these inputs and the fish
selling price that results in financial gain or loss.
Variable and fixed inputs for aquacultural
production systems are similar in nature to those for
other animal husbandry operations. Production
intensity is determined by the blend, quality and
quantity of inputs. Variable input items focused upon
in this study include organic nutrients and chemical
fertilization, fingerlings and production cycle
characteristics. Discussion of variable inputs will focus
on what most of the farmers practiced by size category.
These production systems will be compared across and
within countries.
NUTRIENTS AND FERTILIZATION
Nutrient inputs account for the largest portion
of variable production costs and need to be cost effective
in the locale of the tilapia producer. Combinations of
organic and inorganic fertilizers make practical sense,
are already known to both the farmers and the research
community, and are profitable. Organic and inorganic
nutrient sources can be more economical than
commercial feed, but this is relative to the market prices.
Table 7.5 presents an interpolated summary of
the results by farm size. More detailed presentation is
made in Appendix IV. Nutrient inputs used by fish
farmers ranged from kitchen waste and green manures
to animal manures and supplemental diets. A variety
of available on-farm nutrient sources were used by all
size categories, as were purchased formulated diets.
LE 7.5. PREDOMINANT SOURCES OF NUTRIENT INPUTS
THE PHILIPPINES, HONDURAS AND THAILAND, 1994.
d Nutrient input source
)ry Primary Secondary Tertiary
Kitchen wastes Commercial feed Fresh vegetation
Commercial feed Rice bran Inorganic N
Commercial feed Rice bran Fresh vegetation
Rice bran Inorganic N Chicken manure
Inorganic N Rice bran Chicken manure
Commercial feed Rice bran Chicken manure
Commercial feed Fresh vegetation Kitchen wastes
Inorganic N Rice bran Chicken manure
Rice bran Inorganic N Chicken manure
40
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
In the Philippines and Honduras, the use of
purchased commercial feeds markedly increased with
pond area. The opposite was true for the Thai farms,
Appendix IV. This may be explained by the increased
usage or substitution of chicken manure and inorganic
fertilizers by the medium and large Thai farms in lieu
of commercial feeds. Chicken manure is understood to
be the combination of manure and the substrate used
to absorb moisture in the floor of chicken houses -
wood shavings, straw, or other materials.
Honduras respondents regularly used chicken
manure as a fertilizer. Chicken manure was increasingly
used in the Philippines and Thailand as farm size
increased. Purchased nutrient inputs included fish
feeds, rice bran, rabbit pellets and chicken feed,
Appendix V. Fish feed and rice bran were most widely
purchased in each country.
Commercial fertilizers were used in each
country by all pond area categories, except for the small
pond area in Honduras, Appendix IV. Urea was used
by all size categories in each country, Appendix V. Triple
superphosphate (TSP) and diammonium phosphate
(DAP) were used in Thailand, Honduras, and the
Philippines, respectively.
Integrated animal and fish systems place
animal enclosures next to or over the fish pond allowing
wastes to directly enter the fish pond.
Poultry, hog and ducks were the
primary animals used 
in integrated 
TABLE
systems, Appendix VI. In the INH
Philippines, animal-fish integration Country and
was also important with 28 - 57% of size category
all farms using this system. A greater
variety of animal manures was used Honduras
in the Philippines than in Thailand or Small
Honduras. Fresh animal 
manures Medium
were least used in 
Honduras. Nearly 
Large
all farmers in Thailand relied on Philippines
integrated animal-fish 
systems in 
Small
their tilapia operations. Thai farmers Medi
preferred ducks and poultry in their
Thailand
integrated systems. Small
Medium
FINGERLINGS Large
Farm size differences in
fingerling size, stocking rate, sex ratio methyltestoster
and use of predator species in tilapia - hand sexing
production are portrayed 
in Table 7.6. 2 The predomin
was the snake]
Monosex male tilapia fingerlings 'Guapote tigre'
were used by most farmers in each country no matter
the pond area. The marked advantages to raising all-
male tilapia, i.e., faster growth and no reproduction,
has lead producers to prefer monosex fingerlings
whenever they are available.
All-male tilapia populations used by sampled
farmers were produced primarily through androgen
sex reversal, Table 7.6. The second most common all-
male production methodology was manually
determining the sex ("hand sexing") of individual fish
via visual observation. There was little use of
hybridized tilapia reported. Androgen sex-reversal
method of producing all-male tilapia populations
requires some instruction, but is easily learned.
Androgen-treated feeds are commonly available in
Honduras, the Philippines, and Thailand.
Hybridization is difficult because pure fish
strains must be kept isolated from contamination with
other species and specific mating crosses must be
conducted to obtain monosex populations. Hand sexing
is not difficult but it is labor-intensive, error-prone, and
wastes many female fish.
Stocking density and size of fingerlings are
interrelated dimensions. If fingerlings are very small,
farmers usually place more into the pond, expecting
7.6. TILAPIA FINGERLINGS AND STOCKING PRACTICES
ONDURAS, THE PHILIPPINES, AND THAILAND, 1994.
Fingerling Stocking Monosex Method' Predator
size density Primary Secondary species
2
Cm. No./m
2  
Pct.
4.0 3.5 SRT Manual 88
3.4 2.5 SRT Manual 100
4.0 2.0 SRT Manual 100
2.4 3.3 SRT None 40
2.7 4.6 SRT Manual 15
2.5 5.4 SRT Manual 31
2.4 8.0 SRT None 94
2.3 5.0 SRT None 100
2.2 9.5 SRT None 100
reversal technology refers to the use of the androgen,
one, at the fry stage to direct the sex toward maleness; Manual
the fingerlings by observing genitalia for maleness.
ant predator species used in the Philippines and in Thailand
head (Ophicephalus striatus) and for Honduras it was the
(Cichlasoma managuense).
41
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
higher mortality rates. Larger fingerlings are stocked
at lower rates because mortality is expected to be lower.
This generally holds across the study countries, Table
7.6 and Appendix VII.
In the Philippines, stocking rates increased
with pond area. Monosex tilapia fingerlings were
derived primarily from sex reversal but also through
hand sexing. Nearly all farms stocked a predator species
to control reproduction. There should not be any
reproduction from monosex male populations but
stocking a predator fish can be seen as an insurance
measure against less than perfect sex-reversal
treatments in the hatchery.
In Honduras, the stocking rates were lower
than in the Philippines but larger fingerlings were used,
Table 7.6. Fifty to 92% of Honduran farmers used
monosex male fingerlings obtained from sex-reversal
and hand sexing provided the rest. Again predator fish
were stocked by almost all farmers. This may be for
'insurance' reasons, but also because the Cichlasoma spp.
are desired fish to eat.
In Thailand, the stocking rate was much higher
42 than in the 
Philippines or Honduras. 
Thai stocking rates
were between five to ten fish per M
2
, Table 7.6.
Fingerling size was in the 3 cm range. Monosex male
populations were derived through sex reversal
exclusively and predator fish (snakehead) were stocked
as insurance by almost all farmers.
The source of fingerlings is often a dilemma
for aquaculturists. In many development projects,
government hatcheries are established to provide
fingerlings to project participants. This system usually
deteriorates over time as funds for the project end, or
the demand for fingerlings increases faster than the
station can expand their operations (32). Ideally, private
hatcheries will develop to supply the additional
fingerlings required by fish farmers (52).
In Thailand, 90% of the small and 100% of the
medium and large pond area farmers relied on private,
i.e., non-governmental, hatcheries to provide
fingerlings, Figure 7.4. Ten percent of the small, four
percent of the medium and 21% of large pond area Thai
farmers supplied their own fingerlings.
In the Philippines, 45% of the small, 89% of the
medium and 67% of the large pond area farmers relied
on non-governmental sources of tilapia fingerlings,
Figure 7.4. Production of one's own fingerlings or
obtaining fingerlings from a neighbor accounted for
12% of the small pond area farmers, 55% of the medium
and 17% of large pond area farmers.
In Honduras, for all farm sizes, well over half
the farmers relied on government hatcheries or research
stations for their fingerling needs, Figure 7.4 In the
short-run, these farmers have access to subsidized
tilapia fingerlings. Long-run dependence may curtail
expansion. On the other hand, six to 20% of the farmers
produced their own fingerlings, which is a promising
sign for the future development of tilapia culture.
Interestingly, 10 to 35% of the fingerlings came
from research stations, showing their importance in this
fledgling industry in Honduras. It also suggest that
more effort is devoted to providing producer services
at Honduras research stations than to the conduct of
research. No such fingerling reliance from research
stations was found in Thailand or in the Philippines.
In the Philippines, 22 to 44% of the farmers
interviewed had problems obtaining fingerlings during
the rainy season. In Honduras, 19 to 25% of the farmers
Percent agreement
100
90
8 0 
.. ..........
70 
.S
60
50
4 0..........
Philippines
0 Honduras
Small Medium Large
Size of pond holdings
Figure 7.4. Percent obtaining Tilapia fingerlings from
nogovernmental sources by pond holding, size, and country,
Tilapia farmers, 1994-95.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
had similar difficulties in obtaining fingerlings.
However, the Thai small and medium-size farms had
no problems and only 11% of the large farmers
experienced any problems obtaining tilapia. Thailand's
private fingerling business seemed to meet farmer
demand.
PRODUCTION CYCLE CHARACTERISTICS
Farm size differences in length of the tilapia
production cycle, harvesting strategies and size of final
product are shown in Table 7.7, Appendix VIII and
Appendix IX. The dimension are indicators of
production cycle characteristics and market demand.
Production cycles were the shortest in the Philippines,
ranging from 139 to 149 days. Two crops per year were
usually produced. However, the fish produced were
smaller than in the other two countries, ranging from
173 to 199 grams.
Producing many small fish is ideal for the
farmer, if the consumer will accept a small product,
because it is much more efficient to produce large
numbers of small fish than it is to produce the same
number of larger fish. One large harvest accomplished
by draining the pond at the end of the culture period
was the most frequently used approach. Honduran
farmers had production cycles ranging from 194 to 263
days and one to two crops per year, Table 7.7. The
average fish produced ranged from 274 to 570 grams.
In this country, partial harvesting along with one large
harvest and one harvest only were used.
Thailand had the longest production TAB]
cycle of the three countries. It ranged from 307 AR
to 358 days, Table 7.7. The 
longer cycles resulted Cour
in larger fish for the small and large farms. and
Middle-sized farms had intermediate values
when culture period and fish size are Hon
compared. Less partial harvesting 
was used in Sm
Thailand and one large harvest at the end of Me
the production cycle was preferred, primarily Lar
because larger fish bring a better price and are 
Phili
more easily sold. Sm
Me
MARKET CONSTRAINTS Lai
Operators of different size farms have Thail
qualitatively different sets of marketing Sm
problems due to basic differences in the volume Me
of fish that each is endeavoring to sell. Lai
Identifying the market in which the cultured 
. Har
tilapia are to be sold is an essential element in harv
determining production-marketing viability, not a
An understanding of the product this
characteristics and consumer preferences associated
with the selected market is fundamental in developing
the appropriate production technology.
Where aquaculture is a new enterprise, there
may be no existing marketing infrastructure.
Development of marketing infrastructure for
aquacultural inputs and outputs will often be as
important as soil, water, climate, and nutrients to the
economic viability of aquaculture.
Small-scale farmers who consume most of their
fish harvest or sell it locally have a lesser need for
extensive marketing information. The farmer may be
personally acquainted with most of the final consumers
of his product. However, as the percent of home
consumption of fish decreases and distance to final
consumer increases marketing channels become more
important. Specific information on consumer and
product characteristics will be crucial to expanding
markets and maintaining a favorable price.
Sixty percent of the Rwanda farmers did not
sell any fish from their last harvest. In the small and
medium categories, Honduran respondents kept higher
percentages of their harvested fish for home
consumption, 20% and 12% respectively, than in the
Philippines or Thailand, Appendix X. The percentage
of farmers keeping some tilapia for home consumption
LE 7.7. TILAPIA PRODUCTION CYCLE INFORMATION BY POND
EA IN HONDURAS, THE PHILIPPINES, AND THAILAND, 1994.
itry size Days to Crops per Average Harvest
:ategory harvest year fish size strategy'
No. No. Grams
duras
all 194 2 274 Single
dium 263 1 275 Single
ge 235 1 570 Partial
ppines
all 145 2 173 Partial
dium 149 2 199 Partial
rge 139 2 179 Partial
land
[all 307 1 328 Single
dium 346 1 301 Single
rge 358 1 411 Single
vesting strategies: Partial - partial; and Single - one large
est at the end of the cycle. In Appendix VII, another category,
al + 1 - partial and one large harvest at end of the cycle was
frequently used strategy and is therefore not mentioned in
table.
43
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
decreased as pond area increased indicating that
increased pond area was associated with increased
entry into the cash market economy.
In the Philippines, small pond operators did
not sell all their fish and kept some for home
consumption. Medium and large pond owners sold
100% of their harvests. No Thai respondents, at any
pond area, kept fish for home consumption; all were
sold.
Rwanda farmers sold fish to other buyers
teachers, civil servants, and others making direct
purchases; family members also sold fish in the
marketplace. Thailand, Philippine and Honduran fish
were sold mainly to intermediaries, other buyers,
restaurants and by family members in the marketplace,
Appendix X.
Between 5 and 19% of the Philippine farmers
were able to sell their fish to restaurants and 13 to 47%
of the Honduran farmers sold fish to restaurants and
only a few Thai farmers sold tilapia to restaurants. The
Honduran percentages are much higher than in any
other country. Few Thai or Honduran farmers
personally sold any fish in the marketplace.
RELATIVE PRICES OF FISH
Prices received for tilapia are related to the final
size of the fish, consumer size preference and available
market outlets. In this study, the prices for tilapia were
lowest in Thailand and comparable in the Philippines
and Honduras, Table 7.8.
Consumers in the Philippines paid
prices ranging from $0.97 to $2.34 per
kilogram of tilapia; one kilogram of fish being TABLE
equivalent to 5-6 fish. In comparison, 
the IN
price for fish in Honduras ranged from $0.68 Countr
to $1.65 per kilogram of fish; one kilogram size cat
of fish being equivalent to three fish.
Honduran consumers preferred a larger fish Hondu
than the consumer in the Philippines. Smal
Medi
In Thailand, tilapia prices 
were much Large
lower than in the Philippines or Honduras. Philipp
Tilapia prices ranged from $0.12 to $0.99 per Smal
kilogram of fish. One kilogram of tilapia is Medi
one to three fish. Tilapia in Thailand are
ubiquitous and supply 
is abundant which 
Thailar
Smal
may account for the low price range. Medi
Additionally, the sale of tilapia to middlemen Large
who harvest the fish results in lower prices as the cost
of labor to harvest is subtracted from the tilapia
purchase price.
Prices received by Honduran tilapia farmers
had the most variation. The predominant tilapia size
harvested in Honduras was in the 200 to 300 gram range
for producers with small and medium-area ponds and
greater than 500 grams for larger farms. Some low-
intensity, rural farmers had little opportunity for
marketing their fish and the prices they obtained were
low. On the other hand, large pond farmers produced
bigger fish (larger than 500 grams) that tend to
command premium prices.
TECHNOLOGICAL CHANGE AND AQUACULTURAL
DEVELOPMENT
Economic advantages are found in efficient use
of production ideas. From the data available here, some
general conclusions about what technologies will be
used in the future become clear. Farmers with small,
medium and large tilapia ponds in the three PD/A
CRSP countries are likely to use all-male tilapia
populations. Sex-reversal using androgens was the
method of choice.
The use of commercial fish feeds in tilapia
culture may be prohibitively expensive in some cases.
In rural areas where distribution is difficult, it is not
likely that feeds will be used. Additionally, feed mills
operating in a monopoly environment may have prices
too high for semi-intensive fish farmers. On the other
hand, when fish are grown for export and specialty
markets, the farm will be able to economically use
commercial tilapia feeds.
7.8. AVERAGE AND RANGE OF PRICES RECEIVED FOR TILAPIA
HIONDURAS, THE PHILIPPINES, AND THAILAND, 1993-1994
y and Average price received Range of prices
egory for tilapia received for tilapia
$/kg $/kg
ras
l 1.25 0.68 - 1.94
um 1.23 0.84 - 1.94
1.28 0.84 - 1.65
ines
l 1.70 0.97 - 2.34
um 1.86 1.27 - 2.34
1.80 1.50 - 2.06
l 0.45 0.22 - 0.99
um 0.42 0.12 - 0.60
0.51 0.32 - 0.68
44
-i
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Marketing tilapia varied from primarily home
consumption to widely distributed markets. Marketing
channels for these farmers were not investigated fully.
Much more can be done to improve these channels not
only for fish distribution but also for production inputs
to the farmers.
Dissemination of information about tilapia
production systems and innovations is being carried
out to varying degrees in the study countries. In
Honduras, there was an increasing knowledge of the
PD/A CRSP project with an increase in the pond area.
Predominantly, there was not much extension visitation
to the tilapia farmers interviewed in Honduras.
However, there did seem to be a substantial contact
between fish farmers and government fish culture
extension personnel in the past.
For the small and medium pond area operators,
a third had contact with government fish station staff
within the last six months, while 67% of the larger
pond area operators had contact during this time.
About a quarter of all respondents had some contact
with Zamorano University that works in fish culture.
All Honduran tilapia respondents agreed
they would like more extension involvement.
Approximately one quarter of the Honduran
respondents felt their understanding of growing
tilapia was the main thing that kept them from
achieving larger harvests. Another quarter of the
respondents felt not enough extension was another
reason for low yields.
Twenty to 30% of the Thai respondents had
contact with either Asian Institute of Technology or
Kaesetsart University staff. Little contact with
government fish station staff was reported for the small
(10%) and medium (4%) pond area operators, while
almost 40% of larger operators reported having contact
within the last six months. Eighty to 90% of Thai
farmers would like to have future extension assistance.
Most of Philippine respondents had prior
contact with Central Luzon State University (CLSU) or
Bureau of Fisheries staff. This is not surprising since
the farmers were chosen and interviewed by CLSU
personnel. More small pond operators had
governmental fish station personnel and aquacultural
extension visits than did the medium and larger pond
operators. Most farmers would like increased extension
assistance.
CHAPTER EIGHT
THE INSTITUTIONAL NETWORK FOR
TILAPIA TECHNOLOGY IN FOUR
PD/A CRSP COUNTRIES
INTRODUCTION
This chapter maps each PD/A CRSP project
into the national system of public and private sector
actors in each of the four countries. An institution is a
cluster of roles that plays some function for society; here
the focus is research, extension, and services for tilapia
aquaculture. The narrative briefly identifies the
historical origins of the PD/A CRSP, the institutional
location of the project, the central entities active in
tilapia culture in each country, and the connections
between the PD/A CRSP to others working with tilapia.
Diagrams summarize the relative position of
the PD/A CRSP in each nation relative to other
institutional actors. In an incomplete and abstract way,
the organizational charts are intended to portray the
PD/A CRSP's major relationships to other sources of
technology, assistance, and producer services in each
nation. The major public agencies, educational
institutions, nongovernmental organizations
5
, and
private sector actors are identified. However, the many
kinds and levels of horizontal relationships among
institutional and private sector entities are not
portrayed.
The narrative outlines the basic functions and
programs of the major centers of activity that are
connected in various ways to the PD/A CRSP research
program in each country. It should be noted that an
exhaustive inventory of all tilapia-related projects,
agencies, and firms was not possible in the bounds of
the present project, particularly in a dynamic and
complex environment such as Thailand.
The final section considers the various
alternatives to extending research results to individuals,
groups, and organizations that might use or further
5
Nongovernmental organizations are private, nonprofit
entities that are not directly funded or controlled by the
nation-state. They include international agencies that provide
relief and development assistance. They may be international
agencies such as CARE or Heifer Project International, or
indigenous organizations supported by citizens of a
particular country. The latter voluntary associations usually
are dedicated to assisting the poor or disadvantaged
segments for humanitarian and/or religious reasons.
45
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
extend PD/A CRSP outcomes. It discusses some of the
central issues pertaining to the way the PD/A CRSP is
- and is not - connected to national research systems
and the paths of technology and information that
extend to the farm level.
RWANDA INSTITUTIONS
Rwanda began experiencing incursions from
rebels based in Uganda in 1990. In April 1994, large-
scale fighting broke out in the North of the country
followed by widespread ethnic slaughters, mass
migration, and the fall of the government. All
government services and research programs are now
suspended pending the formation of a new
government. This section describes the institutions that
functioned in Rwanda prior to the 1994 problems. What
staff, equipment, and facilities remain when order is
again established will emanate from the organizations
and programs developed over several decades of
assistance from USAID, from other donor
organizations, and the Rwandan people themselves
(42).
PD/A CRSP Technology Transfer Efforts. A
number of formal and informal mechanisms were used
46 to transfer 
PD/A CRSP 
technology 
in Rwanda. 
A
predecessor project, the Rwanda National Fish Culture
Project (1981-1992) had established an extension
program that is described below. At the same time,
another USAID project renovated the main station at
Kigembe as well a number of satellite stations for
fingerling production and distribution that became
points of contact between researchers and farmers.
On the extension side, from 1983 to 1988 the
PD/A CRSP researcher and her counterpart, Pelagie
Nyirahabimana, trained most of the extensionists,
creating a well-prepared cadre of individuals to work
with farmers. Subsequently, she assumed the PD/A
CRSP research position at the University of Rwanda's
laboratories and ponds. The Rwasave site is some 14
kilometers from the research and demonstration station
at Kigembe. Her 1993 successor, continued the pattern
of close working relationships with Kigembe personnel
and others working in fish culture in Rwanda.
At Rwasave, field days were held for area
farmers and many informal consultations and farm
visits were made. Marketing trials helped establish
some basic parameters about consumer preferences in
the surrounding area. PD/A CRSP personnel often
provided consultation about extension training and
technology development trials at the Kigembe research
station. Unfortunately, budget cuts and an extension
reorganization led the nearly 60 specialized aquaculture
extension monitors to fall under the supervision of the
general agricultural extension organization. Without
ties to field staff PD/A CRSP researchers and Kigembe
managers had to rely on informal contact and periodic
group meetings to convey research results to a
dwindling number of monitors.
In sum, PD/A CRSP technology transfer in
Rwanda was facilitated by good working relations
among the small group of researchers and extension
managers working in fish culture. Word-of-mouth
remains the primary mechanism for technology transfer
in Rwanda. The lapse of support for extension
personnel and governmental reorganization increased
the PD/A CRSP researchers' distance from fish culture
monitors, but the burgeoning interest in fish culture
continued to propel growth in the number of ponds
and amount of fish produced. Until the ethnic conflicts
are resolved, progress in fish culture remains in doubt.
Rwanda Fish Culture Service. This unit of the
Ministry of Agriculture, centered at Kigembe, was the
collaboration point for a USAID aquaculture project.
After the ten years of assistance, a government
reorganization shifted supervision of fish culture
extension workers to the general extension effort. A
number of satellite facilities were then closed or
privatized following a longstanding PD/A CRSP staff
recommendation. Nonetheless, the Service was
permanently established as part of the national
program.
Led by Nathanael Hishamunda, the Kigembe
station became a national demonstration center for
integrated aquaculture. Extension training and farmer
training was conducted on a regular basis. Figure 8.1
outlines the major entities involved in aquaculture in
Rwanda.
The main station at Kigembe is complemented
by a network of more than 10 stations located
throughout the country. The main functions intended
for the outlying stations were fingerling supply and
demonstration of good practice, including integrated
animal-aquaculture systems. Consisting of a few ponds,
a small building, and concrete holding tanks, the
stations often served as a meeting point for farmers and
extensionists. Each was staffed by a manager and a few
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
University
ExtensionAgents
Demonstration
Farmer Training
47
Other Private
Agencies Sector
I
I
Institutons Missionaries Fingerling
School & Prisons & NGO's Vendors
Peace Corps Restaurants
Volunteers
Figure 8.1. Institutional network for Tilapia technology in Rwanda.
laborers. In recent years, some stations were given to the University for the PD/A CRSP activity.
decommissioned or redeployed due to budgetary Although a branch of the University is located in
constraints. Ruhengari, no other institutions or government
agencies have aquaculture staff or research programs.
University of Rwanda. The university The PD/A CRSP project was located at this facility,
provides a degree program and other training in collaborating with University staff and other scientists
aquaculture through the Rwasave station facility associated with a Belgium-supported aquaculture
adjacent to the Butare campus. The station had been research and development effort.
established by the Ministry of Agriculture, but was
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
PD/A CRSP technology informed the conduct
of activities in the National Fish Culture Service through
established working relationships among staff
members at the Rwasave and Kigembe stations.
Training programs frequently were joint efforts and
many of the extension personnel are graduates of
training programs conducted at the two facilities.
Nongovernmental Organizations. As many as
20 nongovernmental organizations (NGOs) - religious
missionaries, humanitarian agencies, and other - have
some aspect of fish culture as part of their program of
activities in Rwanda. There is a great deal of variability
in the level and consistency of technical assistance
rendered to farmers by the NGOs.
PD/A CRSP staff have proved training
seminars, written materials, and various other kinds
of informal help to some of these groups. Recent
conflicts, large-scale migrations, and other disruptions
have shifted the development community's attention
to basic issues of safety and survival of human
populations. As of this writing, the ethnic unrest
characterizing the 1993-96 period has put much of the
progress made in fish culture in doubt.
HONDURAS INSTITUTIONS
Honduras has a complex set of governmental,
nongovernmental, and private sector actors doing
research or providing services for tilapia producers.
Multiple segments of the Honduran government have
aquacultural programs. PD/A CRSP began work with
Ministry of Natural Resources' El Carao National Fish
Culture Research Center at Comayagua in 1983.
Since that time, research has been conducted
on fish stocking rates, and on the use of inorganic and
organic fertilizer, formulated diets, and combinations
of fertilizers and formulated diets for production of
tilapia. The goal of this work has been to increase fish
production and profitability among by small- and
medium-scale commercial producers based on a
technology that relies heavily on enhancement of
natural pond productivity using locally available
nutrient inputs.
PD/A CRSP Technology Transfer Efforts.
6
PD/A CRSP research results have been disseminated
at local, regional and international scientific meetings,
in regular lectures at local vocational-agricultural
schools, at technology-transfer days at El Carao,
through formulation of pond management plans for
producers who buy fingerlings at El Carao, and in
scientific publications. Testing of these production
systems under on-farm conditions would validate
research findings and the PD/A CRSP Pond
Management Guidelines, and serve as a teaching tool
for extensionists and producers.
Another program of technology transfer, the
USAID/Honduras and Ministry of Natural Resources
Land Use and Productivity Enhancement (LUPE)
program, expressed interest in collaborating with
PD/A CRSP in order to promote aquacultural
development as part of its overall effort. The LUPE
program worked with hillside farmers in the southern
and central regions of Honduras to promote watershed
conservation and sustainable agriculture. Population
pressures on the environment are a serious concern in
Honduras (62). Many of the farmers that participated
in the LUPE project had few resources such as fertilizers
available to them; use of compost as a fish pond nutrient
input, as developed in the Rwanda PD/A CRSP, could
be tested in these hillside ponds.
In early 1991, the Honduran PD/A CRSP
principal investigator, Marco Ivan Rodriguez,
developed a program that linked producers in the
northern and central regions of Honduras to El Carao.
These small- to medium-scale commercial producers
were interested in maximizing their profitability by
refining their production technology. This group of
farmers participated in the field trials of PD/A CRSP
production systems developed in Honduras.
Peace Corps/Honduras had an on-going fish
culture project, which placed Peace Corps volunteers
(PCVs) primarily with MNR. The agency's plan for 1991
to 1998 was to improve the economic and nutritional
status of the resource-limited rural population in
Honduras through fish culture. Peace Corps managers
wanted PCVs, where ever possible, to test PD/A CRSP
fish production systems on farms where assistance was
provided. Participation in such trials, however,
depended solely on farmer interest and resources.
The Honduras PD/A CRSP developed a
program to conduct on-farm trials with resource-
limited and small- and medium-scale commercial fish
farmers in the southern, central and northern regions
of Honduras. In April 1991, the PD/A CRSP board
approved the project and project implementation began
in May 1991.
6
This section is largely adapted from Teichert-Coddington,
Green, Rodriguez, Gomez, and Lopez (1992).
48
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
The two components of this project were on-
farm trials and short courses in aquaculture for
extensionists and farmers that participated in the trials.
An initial short course would be given before beginning
farm trials. A second seminar would be given upon
completion of trials to summarize and discuss trial
results. Honduran PD/A CRSP personnel were
responsible for identification and selection of small- and
medium-scale commercial fish farmers to participate
in the on-farm trials managed out of El Carao.
Participant farmers were required to have two ponds
for use in trials to allow two production systems to be
compared.
Each prospective farmer was interviewed prior
to selection; upon selection, the farmer and a PD/A
CRSP representative would sign a contract that
stipulated the responsibilities of each party during the
on-farm trials. MNR extension personnel associated
with PD/A CRSP would make monthly visits to
participant farmers to collect data, water samples and
to provide technical assistance as necessary.
In mid-1991 the DIGEPESCA and LUPE
directors met to discuss the implementation of on-farm
trials of fish culture systems that would be appropriate
for LUPE-assisted farmers. Both Directors agreed that
such a program would be beneficial. LUPE extension
personnel selected by the LUPE project director to
implement on-farm trials were responsible for the initial
selection of candidate farmers.
Only one pond per farm would be used for
trials. Candidate farmers were then interviewed and
briefed by Honduran PD/A CRSP personnel as to
farmers' responsibilities during the on-farm trials,
however, no contract between the farmer and LUPE
was signed. LUPE extension personnel did not require
participant farmers to sign a contract. However, LUPE
extension personnel were responsible for supervising
data collection and providing technical assistance to
participant farmers. A Honduran PD/A CRSP
aquaculture specialist was assigned to accompany
participating LUPE extension agents on farm visits at
least once a month. During each visit, the PD/A CRSP
aquaculture specialist would collect data, water
samples and provide technical assistance as necessary.
LUPE was responsible for transporting the aquaculture
specialist from their Tegucigalpa headquarters to the
field sites.
Peace Corps/Honduras was only collaterally
involved in testing PD/A CRSP production systems on
farm. PCVs were responsible for collecting production
data at each of their sites, but they were not obligated
to test PD/A CRSP fish production systems. In practice,
greatly different situations made it difficult to
standardize inputs and management systems.
The results of the on-farm trials with the small-
and medium-scale tilapia farmers demonstrated that
the PD/A CRSP production systems were more
productive than the traditional tilapia production
system used in Honduras. The limited enterprise
budget analysis indicated that both PD/A CRSP
systems resulted in significant income above variable
costs, an indicator of the economic viability of the
systems. It should be noted that the PD/A CRSP
production systems tested in this trial were not
developed for subsistence fish farmers, but rather for
small-to-medium-scale commercial fish farmers who
have the capability to purchase the necessary factors
of production. It is this group of fish farmers whom
the researchers felt will have the greatest impact on
freshwater aquaculture in Honduras.
One PD/A CRSP production system was not
included in the trials for subsistence farmers - the
green-matter compost system. No farmer felt
sufficiently resource-limited to test the compost system
that was developed by the Rwanda PD/A CRSP. The
researcher observed that there were sufficient nutrient
resources available - manure in fields, agricultural by-
products, and termite nests, etc. - that farmers did not
feel compelled to use compost.
The researchers remarked that any production
system is only as good as the farmer who implements
such a system. Farmers who complied with the
workplan, i.e., were good managers or farmers,
obtained consistently high yields that approximated
those attained on the experiment station. Non- or
variably-compliant farmers obtained proportionally
lower yields. This observation applies equally to
farmers associated with the on-farm trials.
To develop and implement an on-farm testing
program is an ambitious endeavor. The on-farm trials
were the first such activity undertaken as part of the
Honduras PD/A CRSP, and a few lessons were learned.
Participants from all of the sectors active in fish culture
in Honduras were sought. As such, the on-farm trial
49
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
activities were dispersed country-wide. However, this
involved interaction with a number of agencies other
than the PD/A CRSP host-country counterpart, and
effectively limited staff control over the trials.
Cooperating agencies always expressed
interest and commitment to the trials, but since the
trials, and sometimes aquaculture, were not specific
objectives in the agencies' annual workplans, field-level
execution of the trials often suffered. It is important that
the researchers have direct input into the execution of
the field trials to ensure that the protocol is adhered to
and that proper, complete data is collected. These
shortcomings must be rectified if future on-farm trials
are to be conducted in collaboration with other agencies
in Honduras.
The trials conducted directly by El Carao and
PD/A CRSP personnel also involved farmers located
in diverse geographic regions of Honduras. As a result,
much time and expense were expended on travel; time
spent on travel was time not available to work directly
with participant farmers. Future trials should be limited
to one to two geographic zones, e.g., the Comayagua
Valley, at a time, which would allow greater contact
50 with the farmers 
of each zone and 
a more efficient
transfer of technology. Subsequent trials would then
be conducted in a different geographic zone. Thus the
beginnings of a technology transfer program met
institutional resource limitations that must be
understood before subsequent efforts are undertaken.
Figure 8.2 diagrams the network of organizations and
agencies working in Honduran aquaculture.
Direcci6n General de Pesca y Acuicultura
(DIGEPESCA). DIGEPESCA is a division of the
Ministry of Natural Resources. Although efforts to
change traditional practices are underway, the system
of political patrimony in Honduras has caused
DIGEPESCA to change directors, on the average, at
least once a year. Thus continuity of leadership in a
central government agency has presented a problem
for aquaculture in Honduras.
DIGEPESCA works with many other
organizations to promote aquaculture. For example, a
seminar concerning the nutrition of aquatic organisms
(shrimp and fish) took place in the town of San Lorenzo,
department of Choluteca in September 1993. It was
organized by DIGEPESCA, but was not widely
publicized. Some of DIGEPESCA employees have
traveled to Costa Rica, sponsored by FAO, to attend
seminars on fish nutrition and processing techniques.
Centro Nacional de Investigaci6n Pisicola.
Built in 1980, and located in the department of
Comayagua, the El Carao station is the main supplier
of fingerlings in the country. El Carao, managed by
the Direcci6n General de Pesca y Acuicultura
(DIGEPESCA), produces fingerlings of red tilapia, black
tilapia, common carp, grass carp, silver carp, tambaqui
and guapote tigre. The PD/A CRSP tilapia research
program is based at this station.
El Carao has 41 ponds with an area of 52,300
m
2 
of water surface. In 1992 they reported production
of about 3 million sex-reversed tilapia fingerlings
(nilotica and red). El Carao gave technical assistance to
271 producers from 15 different departments.
According to their data they stocked about 338 ponds
for a total of 472,000 m
2 
of water surface.
During 1992, the staff taught four short courses
and produced, together with PD/ACRSP help, a
document "Divulgacion del Documento Sobre Enlace
Tecnologico". They collaborate with three schools from
the area to allow students to do their practical
internships at the station. El Carao has ties with the
Chinese Mission, USAID, Asociaci6n Nacional de
Acuacultores Hondurefios (ANDAH), Federaci6n de
Productores y Exportadores (FPX) and Federaci6n
Hondurefia de Inversionistas Agricolas (FHIA).
Estaci6n Pisicola del Instituto Nacional
Agrario. The fish station of the National Agrarian
Institute (INA), Rio Hondo is located in the community
of Santa Barbara, The station was built in 1986 in
conjunction with the Tilapia Food Aid Organization, a
project involving the Belgian and Honduran
governments. This 19,000 m
2 
fish station, designed to
produced about 500,000 fingerlings per year, has 25
ponds. It also has a wet laboratory with circular tanks
for carp reproduction, a building with rooms for offices,
board and classes, and a staff of 12 employees.
The Rio Hondo station sells fingerlings at a
subsidized price (tilapia nilotica and red tilapia), but
INA is not interested in this station and has attempted
to privatize it. The Chinese Technical Mission has
expressed interest in a joint venture with INA to run
this station. Since INA only works with farmer groups,
it seemed that the station might be given to the Union
Nacional de Campesinos (National Farmers Union), but
was instead given to DIGEPESCA.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
F
National Research Center
El Carao Comayagua
u nliversity _xtrision
51
Other Research Agrarian Institute
& Training Rio Hondo
Organizations Santa Barbara
Save the Children
Figure 8.2. Institutional Networks for Tilapia technology in Honduras.
Fish Sub-Station Santa Barbara. A fish station red tilapia, common and silver carp and tambaquf. They
is managed by DIGEPESCA and located in the do not reproduce their own fingerlings but receive
department of Santa Barbara. It consists of eight small fingerlings from El Carao fish station to be distributed
ponds of about 200 m
2 
each for a total of 1,800 m
2 
of to fish producers of the area - both stations are
water surface. The species cultured are tilapia nilotica, managed by DIGEPESCA.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
The station is staffed by an Engineer
Agronomist, DIGEPESCA's extension agent for the
area, and two guard/laborers. The lack of budget,
management and facilities makes this station less
useful. The Rio Hondo, Santa Barbara fish station is
only 15-20 minutes drive from this station and has far
more potential; neither one is reported to be functioning
well.
Panamerican Agricultural School. Escuela
Agricola Panamericana El Zamorano was established
in 1942 by Mobile, Alabama banana magnate Sam
Zemurray. Since 1987 it has graduated Engineer degrees
in Agronomy. The Agronomy degree is a three year
degree and the Engineer in Agronomy is a four year
degree. Known as Zamorano for the hacienda that
previously owned the land, the school has eight
Departments; Dr. Daniel Meyer is head of the Biology
Department and teaches the course of Aquaculture.
The aquaculture program has worked since
1976 with the main objective of training students in the
fundamentals of aquaculture. They attempt to teach
students the different levels of aquaculture from
extensive to intensive. Many Zamorano graduates are
52 
working 
with the 
shrimp industry, 
but just 
a few work
in the tilapia industry.
The Zamorano aquaculture unit has several
earthen ponds - not uniform and enough to do
research - and eight concrete tanks to do tilapia sex-
reversal. They also conduct integrated farming with
swine and duck enclosures next to ponds. They
annually produce about 100,000 sex-reversed tilapia
fingerlings; 60,000 for their own needs and the rest to
sell to area farmers. El Zamorano is the only educational
institution doing tilapia sex-reversal in Honduras. They
supply fingerlings to farmers in the departments of
Olancho and Francisco Morazan.
Universidad Nacional Autonoma de
Honduras (UNAH). Located in Tegucigalpa, the
Universidad Nacional Autonoma de Honduras
(UNAH) teaches and conducts limited research in
aquaculture through their biology department. They
have a staff of five instructors in various ways related
to aquaculture. Students take field trips to El Zamorano
university, El Carao government station,'Rio Hondo
government station (Instituto Nacional Agrario, INA),
and private shrimp farms. UNAH makes educational
exchanges with the Centro Universitario Regional del
Litoral Atlantico (CURLA) which is a regional annex
of UNAH. The UNAH does not fish ponds or
laboratories to teach or to do research in fish culture.
The Universidad Pedag6gica Nacional, which
is also an autonomous university, is planning to begin
teaching some tilapia culture. Teachers of primary and
secondary schools will be trained in the basics of fish
culture. Teachers can then provide instruction in fish
culture in the schools, particularly in rural areas.
Escuela Nacional Agricola. The Escuela
Nacional Agricola (ENA) is located in the town of
Catacamas, department of Olancho. Managed by the
Ministry of Natural Resources (Ministerio de Recursos
Naturales) as a semi-autonomous institution, the 250
students school offers a three-year Agronomy degree.
A fish culture course is taught for third-year students.
Students taking this course must do 20 to 30 hours of
theory and 45 to 50 hours of field practice.
ENA fish culture facility has 26 ponds that are
used for education, training, and to produce food for
their students; they are not used for research. They have
the facilities to do tilapia sex-reversal, but it is not being
done due to lack of resources. A teacher and a guard/
helper are the only two persons involved with the ENA
fish program. ENA has ties with the Ministry of Natural
Resources, the Japanese Mission, the Canadian
International Development Association (CIDA), the
European Community (EC) and Partners of the
Americas through their Farmer to Farmer program.
The Organizaci6n Latino Americana para el
Desarrollo de la Pesca (OLDEPESCA- Latin American
Organization for Fisheries Development) has a branch
for Central America called PRADEPESCA (Proyecto
Regional de Apoyo al Desarrollo de la Pesca en Centro
America). With EC money they started the construction
of a 14 pond research unit in Catacamas; about five
minutes drive from the ENA campus.
The Centro Piloto Demostrativo A ricola
(Demonstrative Research Unit) "EL Espino" is a
collaborative venture between ENA (Ministry of
Natural Resource) and PRADEPESCA. The integrated
research unit has facilities necessary to do research with
swine, poultry, cattle, rice and fish.
With this station ENA will be able to do
research, train students, as well as generate and transfer
technology. The station was managed by PRADEPESCA
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
during the first year and then by ENA. This research
unit should be a very important step in the future of the
Honduran fish industry, especially in integrated fish
culture.
John F. Kennedy School. Escuela de
Agricultura John F. Kennedy is located in the town
of San Francisco, department of Atlantida. It belongs
to the Ministry of Public Education and graduates
Agronomists after three years of studying. At present
they have about 100 students although the school has
capacity for about 350 students. The 17 fish ponds
have 12,200 m
2 
of water surface. A severe shortage
of operating funds retards the operation of this
facility.
Luis Landa School. The Luis Landa School is
located in the small valley town of Nacpome, close to
Choluteca. It offers a bachelor's degree in fisheries.
United Nations Food and Agricultural
Organization. The Food and Agricultural
Organization (FAO) has supported the tilapia
industry in Honduras since 1985 with the
construction of the Santa Barbara station at Rio
Hondo. Through FAO, the "Red Nacional de
Acuicultura" (National Aquaculture Network) was
created in 1992. This network integrates international
institutions and the private and public sector of
Honduras. This network was in place for about a year
but it does not now operate; apparently due to
political reasons. At first FAO acted as a promoter
and then as facilitator so that the network could be
managed by local individuals or organizations.
PHILIPPINE INSTITUTIONS
The institutional system for technology
development in the Philippines is characterized by
multiple organizations with little national coordination
or exchange of materials. The PD/A CRSP is located in
the heart of the central tilapia producing region of the
country at the leading governmental and university
center for aquaculture research. Figure 8.4 profiles the
institutional system working in aquaculture in the
Philippines.
A small set of powerful industrial firms play
a significant role in the expansion of the industry
toward export markets, although current tilapia
production is almost entirely consumed internally.
The national devolution of extension services to
provincial governments has virtually eliminated
public extension services to farmers. Feed company
sales representatives remain the main source of one-
to-one farm visits for technical assistance for fish
culture in most areas of the country.
PD/A CRSP Technology Transfer Efforts. The
PD/A CRSP project has only recently returned to the
Philippines after a several year hiatus. It is the only site
without an expatriate scientist located in the country.
Experienced Philippine scientists in the Freshwater
Aquaculture Center (FAC) at Central Luzon State
University (CLSU) on Central Luzon Island collaborate
with the PD/A CRSP researcher from the University
of Hawaii. Periodic visits are made to coordinate
activities. Significant institutional resources are located
on the CLSU campus; the headquarters for the national
aquaculture extension staff, a provincial hatchery and
fingerling distribution center, and the Freshwater
Aquaculture Center.
PD/A CRSP technology in the Philippines is
complemented by two genetics projects located at
CLSU. These efforts promise to deliver significant
benefits to tilapia farmers. The GMIT project will
provide an alternative to conventional sex-reversal seed
stock production using super-female broodstock to
produce predominantly male fingerlings. PD/A CRSP
production strategies complement the efficiency gains
and possible marketing advantage of this technology.
The GIFT project has initiated a comprehensive
breeding program to identify superior tilapia genetic
stock and to disseminate it to hatcheries in the
Philippines and other countries. PD/A CRSP
production technology also complements the breeding
improvements this effort has made.
The proximity to other research projects and
outreach activities is a major technology transfer
mechanism for the PD/A CRSP. The circumstances
encourage the synergism of PD/A CRSP findings with
other research work on genetics to directly contribute
to an ongoing dialogue with producers, hatcheries, and
feed companies over the development of the
aquaculture industry in the Philippines.
Large-scale corporate interest in tilapia
production is high, given the high relative price for the
fish and the broad base of consumer acceptance and
regular consumption of tilapia. Feed companies
promote tilapia production primarily to increase the
demand for feed products.
53
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Other
Agencies
Provincial
Extension
PCAMRD
Los Banos
ICLARM
Manila
GIFT Project
Implementation
Other
Universities
Figure 8.3. Institutional networks for Tilapia technology in the Philippines.
PD/A CRSP research results suggest that full- are being made by feed company technicians; nearly
cycle feeding of tilapia may not be an optimal all printed technical material available to farmers
production strategy; rather that pond fertilization emanates from feed producers.
complemented by later stage fish feeding may produce
optimum economic benefits for farmers. Unfortunately, Freshwater Aquaculture Center. The
the only regular on-farm contacts to tilapia producers Freshwater Aquaculture Center (FAC) is a semi-
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
autonomous unit of the university, functionally serving
as a research division parallel to the CLSU College of
Fisheries. The Dean of the College is presently serving
as the director of the Freshwater Aquaculture Center
(FAC). The FAC staff have joint appointments to the
College, they teach courses, and they direct graduate
study. The FAC has a national mandate to conduct
freshwater aquaculture research on inland fishes.
In addition to the PD/A CRSP, FAC has
collaborative projects with ICLARM and the GIFT
project, the International Foundation for Science on
waste recycling, International Development Research
Center (Canada) on fish genetics, Overseas
Development Authority (UK) on fish genetics, and a
joint ODA-Thai Government project on fish health. In
addition, the Philippine government sponsors projects
on catfish reproduction, catfish triploid, and
karyotyping.
Bureau of Fisheries and Aquatic Resources
(BFAR). A national division of the Philippine
Department of Agriculture, BFAR maintains a research
unit on the CLSU campus that is supported by ODA
and ICLARM funds. In Mufioz, the BFAR-NFFTRC
(National Freshwater Fisheries Technology Research
Center) is staffed by more than 30 professional staff.
Educational programs primarily are directed to fish
farmers through the Center and the satellite stations.
The CLSU facility is a national breeding center
for freshwater fishes, supplying tilapia fingerlings to
area farmers. Satellite stations in each of 13 regions of
the Philippines also produce fingerlings and advise
farmers. At the CLSU main station, all-day farmer
training programs are offered each Wednesday. BFAR
is the lead agency for the dissemination of the GIFT
fish in the Philippines.
The primary relationship of BFAR to the PD/
A CRSP project is one as a consumer of PD/A CRSP
research results. The strong informal network
connecting BFAR and FAC allows frequent
collaboration, sharing of resources, and communication
between the units. Most BFAR staff are current or
former students of the CLSU College of Fisheries. The
units frequently share resource persons for training
programs offered at various times by each unit. The
GIFT project is the primary formal mechanism of joint
effort at the present.
Provincial and Municipal Extension. A recent
reorganization of the national extension system has
devolved most extension responsibilities to the
provincial and municipal level. Many of these
individuals formerly worked for the national service.
Many have been trained in aquaculture and the various
provincial aquaculture programs very much depend
on the backgrounds of the extension staff. In Nueva
Ecija, the provincial government has established a
hatchery on the CLSU campus. The function of this unit
is primarily to supply fingerlings to farmers at free or
subsidized prices. A BFAR staff member has been
seconded to operate this unit for the province. Few
other provinces have hatcheries or extension
aquaculture programs. These programs have very
limited and indirect connections to PD/A CRSP
activities.
International Center for Living Aquatic
Resource Management (ICLARM). This organization
seeks to provide global leadership in aquacultural
technology dissemination and development. ICLARM
sponsors collaborative research through national
institutions and is a major instrument for delivering
donor aid for aquaculture in developing countries. Part
of the CGIAR system of international agricultural
research institutions, ICLARM provides funding and
coordination to the tilapia research program in the
Philippines in several fundamental ways. Its projects
are influential and well-publicized. It also serves as a
global clearinghouse for information about tilapia
research and demonstration activities.
One central activity is the Genetic
Improvement of Farmed Tilapias (GIFT) project. This
project endeavors to bring well-documented tilapia
germplasm from Africa to Asia where the species are
already farmed, for establishing base populations from
which genetically improved tilapia strains for farming
will be developed. The effort has used eight strains to
breed a faster-growing, larger fish.
The GIFT project supports counterpart projects
at national institutions; FAC and BFAR in the
Philippines. Other efforts supported by ICLARM have
to do with information management (FISHBASE) and
maintaining an extensive aquaculture library at their
Manila headquarters. They have supported previous
work on rice-fish culture and served as advisors for
projects supported by other donors.
55
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Philippine Council for Aquatic and Marine
Research and Development. A unit of the Department
of Science and Technology in the Philippine National
Government, the Philippine Council for Aquatic and
Marine Research and Development (PCAMRD) funds
research and training at various institutions. It funds
projects throughout the country, including a variety of
tilapia research projects at a number of institutions. In
recent years, the main topics have been on sex-reversal
techniques and brackish water production. The
Director, Dr. Raphael Guerroro, is a national leader in
the propagation of sex-reversal technologies for tilapia
fingerling production. He continues to be an influential
figure in the industry.
Southeast Asian Fisheries Development Center.
The Southeast Asian Fisheries Development Center
(SEAFDEC) is headquartered in Ilo-Ilo in the Visayas
Islands. It has one research station that conducts some
tilapia research. Located in Binangonan, Rizal Province
in the South of Manila, this station primarily focuses on
carps, conducting only limited research on tilapia.
University of the Philippines-Los Banos.
Individuals pursue aquaculture topics in fulfillment of
degree requirements for biological studies in various
56 departments. Several faculty members have tilapia
research projects. One project focused on fish pond
management in volcanic areas. Another small-scale
agriculture project has an aquaculture component
focusing on integrated agriculture-aquaculture systems
on limited-resource farms.
Regional State Universities. A number of
educational institutions throughout the Philippines
provide course work, degree programs, practical
training, and limited research efforts on tilapia. Most
notable are University of the Philippines-Visayas where
work and instruction pertaining to brackish water
tilapia production is underway. Cagayan State
University, Isabela State University, Nueva Viscaya
State University, Bicol State University, Pangasinan
State University, Mindanao State University, Don
Mariano Marcos Memorial State University and others
offer course work, some research and practical training
in aquaculture, including tilapia. These units might be
characterized as indirect consumers of PD/A CRSP
technology. They frequently contact FAC staff for
research results and publications.
These institutions may utilize PD/A CRSP
research findings in teaching, research, and training
programs. No systematic network has been established
common ties to CLSU through education, training, or
other experiences. This group of researchers, teachers,
and trainers remains a potential audience for the results
of PD/A CRSP research.
Nongovernmental Organizations. Non-
governmental Organizations (NGOs) are important
conduits of technology and organization to the
grassroots in rural areas of the Philippines. A diverse
set of these private, nonprofit organizations utilize
aquaculture as a component of their portfolio of rural
development activities. What is presented here is by
no means a comprehensive portrayal of NGO activity
in the Philippines nor of the role of this sector in
aquacultural development.
One of the more salient actors in this sector with
respect to tilapia technology is the International
Institute for Rural Reconstruction. Headquartered in
Cavite, it has utilized CLSU staff as resources in training
programs and promotes tilapia culture among small
holders. Its local counterpart the Philippine Rural
Reconstruction Movement is located in San Leonardo,
Nueva Ecija.
Another NGO is the Technology and
Livelihood Resource Center in Manila. It funds local
initiatives in aquaculture and other activities and
provides training. NGO's represent a relatively
untapped audience for PD/A CRSP technologies,
largely because their activities are so diverse and
fragmented. Systematic communication with this
aggregate of entities is difficult, yet they remain a
significant mechanism for wholesaling technologies to
local communities and producer groups in the
Philippines.
Feed Corporations. The animal feed industry
has correctly identified tilapia culture as a major new
source of demand for their products. In the Philippines,
some of the major companies include: San Miguel
Corporation, Vitarich, Robina, and others. These firms
promote tilapia production through their network of
feed stores and technicians prepared to extend a tilapia
production regime that emphasizes feeding over
fertilization. Some of the firms have established
hatcheries to supply fingerlings to their customers.
Farmers employing feed company technologies are
provided a well-organized recipe for feeding and pond
management.
PD/A CRSP technologies in some ways
contradict or supplement the approach extended by
to communicate or link these researchers. Many have
commercial feed producers. The corporate strategie
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
tend to maximize feed purchases, while discounting
the benefits of fertilization and natural algae production
in the ponds. They are inclined to emphasize the taste
of fed fish, perhaps exaggerating the risks of off-flavor
associated with manuring and fertilization. The latter
strategies, however, may be economically optimal for
many producers even though they are not treated as
options in the technology packages extended by the
firms. The PD/A CRSP plays an important role as a
source of balanced, comprehensive information about
the actual benefits of feeding and the identification of
economically optimal strategies for generating income
and reducing risk in tilapia production.
Private Hatcheries. Local fingerling suppliers
provide seedstock for tilapia producers who cannot
readily access BFAR supplies. They also present
alternatives and some level of competition to the public
sector encouraging the forward evolution of quality and
availability of seedstock.
Local hatcheries have difficulty establishing
producer confidence in the quality and reliability of
seed supplies. Hatchery operations can be very
profitable, but also can undermine the progress made
in tilapia culture when extensive crop failures or other
problems result from hatchery misrepresentations.
Some farmers prefer private hatcheries because of the
proximity and the established personal relationship
with the owner that increases their confidence in the
transaction.
The private hatchery sector represents a largely
untapped audience for PD/A CRSP technology. Private
operators represent a diverse and dispersed aggregate
with whom systematic communication is difficult. They
do represent a set of establishments with regular
contacts with large numbers of farmers. They present
an opportunity to share production recommendations
and fertilization strategies based on PD/A CRSP
research directly to the intended target group. Given
the devolution of extension responsibilities and control
to the provincial government level, PD/A CRSP
technology is only indirectly influencing production
practices.
THAILAND INSTITUTIONS
Aquaculture is big business in Thailand.
Shrimp farming is extensive and the government has a
well-organized research and extension system with
faculties in nearly every Thai province. Tilapia culture
is widely practiced. The institutional system for
aquaculture in Thailand is probably one of the strongest
experience with aquaculture coupled with a
comparatively well-developed public technical system
supports a burgeoning aquaculture industry. A large
and aggressive private sector complements the
pervasive presence of fish culture on Thai farms.
PD/A CRSP Technology Transfer Efforts. In
Thailand, the PD/A CRSP has benefitted from its
institutional location at theAsian Institute of
Technology that supports a formal outreach program
that takes research findings to farmers in the region.
PD/A CRSP staff have provided seminars and maintain
consulting relationships with several large feed
companies that themselves maintain field staffs that
provide technical information to farmers.
PD/A CRSP technology is transferred to large-
scale private sector firms in a number of ways. On main
avenue is through direct employment of PD/A CRSP
scientists as consultants or as resource persons in
corporate-sponsored conferences or training programs.
Another is the network of relationships between PD/
A scientists and industry personnel.
PD/A CRSP researchers often participate in the
thesis research of individuals who take jobs on
industrial-scale fish farms or in other positions
associated with aquacultural activity. Other donors
have supported the Northeast Thailand Project that
provides outreach activities in terms of technical
assistance and community organization to poor villages
in that region.
The stream of research findings from the PD/
A CRSP are a significant part of the aggregate research
effort at the Asian Institute of Technology. This program
makes a signal contribution to the development of
aquaculture in Thailand and Southeast Asia. Figure 8.3
diagrams some of the major actors working in
aquaculture in Thailand.
Asian Institute of Technology. An
international institution devoted exclusively to research
and graduate instruction, The Asian Institute of
Technology (AIT) is located on the edge of greater
Bangkok. An autonomous, international, post-
graduate, technological institution, the Institute was
recently reorganized into four schools with the
Aquaculture Program placed in the School of
Environment, Resources, and Development. With 9
doctoral faculty and 20 others with graduate degrees,
AIT offers Ph.D. and master's degrees as well as a
widely-recognized aquaculture short course training
iprogram. In addition to a reservoir, the facilities include
57
in Asia. Widespread indigenous knowledge and\
58
Figure 8.4. Institutional networks for Tilapia technology in Thailand.
about 150 earthen ponds, 120 concrete tanks, two
hatcheries, and cropland on a ten hectare site (17).
PD/A CRSP researchers have been located at
AIT over the life of the project; additional staff have
been supported for shorter periods as budgets and
research needs dictated. The PD/A CRSP research in
Thailand is complemented by the extensive research
program at AIT. Researchers supported by the British
Office of Development Assistance (ODA) and other
donors identify as well as eliminate possible
alternatives to the core pond management principles
identified by the PD/A CRSP. For examples, the
usefulness of early-stage fertilization in the tilapia crop
cycle was clarified here; the low utility of buffalo
manure as a pond input was established by AIT
research.
Thailand Department of Fisheries. A well-
developed and reasonably well-supported research and
extension system is in place in Thailand. The
Department of Fisheries has strategically placed
stations throughout the country. Each province has an
extension office; many also have research stations
though they are not always co-located with extension.
Plans are to link each provincial office to headquarters
staff through computer modems, primarily for data
transmission.
Tilapia farmers have little or no contact with
extension, largely because there are so many fish
farmers and apparently little expressed need for
extension assistance. Long experience with fish culture
and a rich and inventive farming tradition has led Thai
farmers to be quite responsive to market-driven
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Department of Nongovernmental
Fisheries Organizations
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
technological advance. The widespread development
of private sector infrastructure for fingerling
production, custom harvesting, and processing also
lessens the need for extensive outreach activities, at least
in wealthy central Thailand areas.
In Northeast Thailand, soils are poor and
poverty is widespread. AIT has utilized donor
assistance to mount a project targeting poor farmers
with a comprehensive program of assistance featuring
aquaculture as a central point of intervention. PD/A
CRSP researchers have conducted trials at Department
of Fisheries stations, and have participated in staff and
farmer training. PD/A CRSP researchers have prepared
farmer-friendly printed materials for distribution to
farmers by hatchery managers when farmers purchase
fingerlings. Though the efforts are largely localized to
one location in the central tilapia production region,
demonstrable progress has been made in bridging
research findings to on-farm practice and the
recommendation for practice made by the Department
of Fisheries.
Kaesetsart University. Located adjacent to the
Bureau of Fisheries in Bangkok, Kaesetsart is the largest
source of trained graduates in aquaculture in Thailand.
All levels of graduate training take place at this
institution. It has received major donor support in fish
disease research and other areas of aquaculture. The
research program here complements and extends the
activities of the PD/A CRSP. Although only 14
kilometers from AIT on a major highway, most PD/A
CRSP activity operates through AIT programs.
Other Universities. Thailand is a rich
environment for aquacultural education and research;
many degree programs and research projects are to be
found. A number of regional universities and institutes
offer degree programs and training in aquaculture.
Several universities have nascent research programs in
aquaculture. There are many local training programs
and university or college-level courses in aquaculture
taught across the nation. The connections to national
research and extension institutions are tenuous;
similarly the impact of PD/A CRSP technology on these
actors is limited at best.
Nongovernmental Organizations. Thailand
has a diverse, active, and well-developed cadre of
nongovernmental organizations (NGOs) that pursue
rural and agricultural development. Many treat
aquaculture as one of a portfolio of activities to be
selected by local interest and opportunity. Many NGOs
have strong relationships with local institutions of
higher education, some of which feature aquaculture
as a subject-matter. Staff members often become
resource persons for these efforts and local promoters
of aquaculture.
Some international NGOs feature aquaculture
assistance as one option for local development projects.
For example, Heifer Project International has utilized
aquaculture as one possibility for Hill Tribe villages in
Northern Thailand that are seeking alternative uses for
marginal lands and additional sources of farm income.
The Thai NGO sector is a major constituency for PD/
A CRSP research results, publications, and training
program assistance.
Private Sector. Several large feed companies
produce fish feed and compete with each other for
grower business by providing technical assistance
featuring feed-based production strategies. These
production strategies are often in conflict with PD/A
CRSP recommendations that are intended to optimize
fish growth and farmer income, and not feed sales.
Some firms also process fish for export using
fish from company-operated ponds as well as fish
purchased from private farmers. These processing
facilities can be important markets for farmers
producing sufficient quantities of fish that meet quality
standards.
A widespread network of hatcheries provides
many alternative fingerling sources for Thai farmers.
Hatchery operators are a significant target audience for
the results of PD/A CRSP research because of the
technology they employ in producing all-male
fingerlings and the potential these individuals have to
reach tilapia producers.
When tilapia farmers visit hatcheries, they
often spend significant amounts of time visiting with
other farmers while waiting for their fingerling orders
to be filled. Information about production strategies,
feeding approaches, pond liming and fertilization,
disease monitoring, and other needs can be readily
disseminated at this time. In Thailand, some restocking
is done on a custom basis or fingerlings are delivered
by the hatchery. Some farmers send employees or
family members to the hatchery. Consequently, some
fish farmers cannot be reached in this way. Nonetheless,
the hatchery remains a significant nexus for the transfer
of technology.
59
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
CHAPTER NINE
CONCLUSION: TILAPIA TECHNOLOGY IN
FOUR PD/A CRSP COUNTRIES
This report has provided a socioeconomic
profile of tilapia culture in four PD/A CRSP countries.
One of the signal contributions of this study is the cross-
national comparative data obtained from fish farmers
across the globe. A common interview guide and data
matrix provide an initial framework for contrasting and
understanding the practice of tilapia culture.
Similarities in technology and approach to aquaculture
also can be counterpoised to the great differences in
market receptivity, price, and dietary role of tilapia in
each country. The findings illustrate the diversity of
institutions, farm situations, and market conditions
where tilapia are grown and consumed. Readers of this
report should have a more comprehensive grasp of the
meaning of tilapia as a livelihood, the institutional
structures that provide research and extensions
support, and the diverse roles the tilapia enterprise
plays in various farming systems.
In particular, the data examined here
complement experimental and biological information
about how tilapia are grown and used. The findings
show how farmers feed their fish, who they sell them
to, and what kinds of problems they are experiencing.
Farmer attitudes toward tilapia farming and the role
of tilapia production within the four PD/A CRSP
countries were examined by asking them to compare
aquaculture with other farm activities. Operators were
consistently favorable in their perceptions of tilapia
culture on such dimensions as cash income potential
and general attitude toward the enterprise.
Farmer attitudes toward aquaculture also
reveal their perception of overall viability of tilapia
culture. Such qualitative measurements, in effect, ask
farmers to rank the profitability and resource efficiency
of each of their farm production activities. Farmers
generally felt that tilapia was the best use of the land
occupied by the pond.
Results of this study also suggest that tilapia
mean different things to different segments of the farm
operator population. Clearly the wealth or income level
of the grower enters into the amount of capital
investment and risk to be undertaken. Off-farm
employment and life cycle considerations also play a
role in determining the production strategies employed
and the kinds of benefits individuals seek from the fish
culture enterprise.
IMPACTS OF THE PD/A CRSP
Tilapia growers in each of the countries face
vastly different institutional systems supporting tilapia
production. The impacts of the PD/A CRSP are muffled
by the inherent characteristics of the research process,
the nature of institutional functioning in developing
countries, and the dynamism of the information
environment for aquacultural technologies. No farmers
we interviewed had any direct or detailed knowledge
of the PD/A CRSP research program or its findings.
The communication process linking
experimental pond to farm practice involves several
layers of translation and transmission. Many factors
interact to affect the nature and extent of impact PD/A
CRSP scientists and research programs have on national
aquacultural institutions and farm practice.
Experimental findings are at base
experimental; that is, they reflect controlled conditions
and careful measurement of a focused set of factors.
Farm conditions reflect variable physical and
management situations that often mitigate the impact
of effects identified by repeated experimental trial.
Experimental findings must be cumulated from many
studies and modified in certain ways to generate a
robust field recommendation. In essence, an internal
process of recognition and acceptance must take place
within national research and extension systems before
the findings become farm-level practice. Typically,
greater the deviation from conventional understanding,
the slower the process of internal diffusion. Other
factors also intervene.
In Thailand, an extensive and well-trained
network of Department of Fisheries research stations
and extension offices is augmented by a broad set of
colleges and universities that provide baccalaureate and
post-graduate training in aquaculture. An aggressive
private sector supports a wider network of producer
services in Thailand. Firms supplying feeds, fingerlings,
and custom harvesting and marketing are the most
60
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
well-developed here. Several large feed companies and
many small processing and fingerling supply firms
provides most tilapia farmers in the greater Bangkok
area with ready access to inputs and markets.
Large feed companies also promote tilapia
culture in the Philippines, though an extensive network
of private fingerling suppliers has yet to develop there.
Nor is the network of producer services as well
developed as in Thailand. Nonetheless, the Philippines
has several university programs in aquaculture, but not
the extensive network of research and extension offices
found in Thailand. Central government support for
most kinds of extension work has been withdrawn. A
few large feed companies are beginning a serious
promotion program for tilapia production, albeit in a
self-interested manner that emphasizes the use of
purchased feed (their products) and neglects pond
fertilization.
Tilapia farmers in central Luzon have a variety
of publicly supported fingerling producers, while
private sector seed suppliers are beginning to increase
in number in other parts of the country. The high
relative price for tilapia in the Philippines presents a
happy situation for tilapia producers as long as the fish
remains a popular and affordable item in the market
place.
Honduras faces fundamental difficulties with
an underdeveloped marketing system and an uneven
set of consumer preferences for tilapia. The public sector
in Honduras is under great financial stress and is widely
lacking in public confidence over its ability to deliver
services and provide assistance in an effective and
reliable manner. Coupled with inadequate operating
funds, the agencies serving aquaculture have high
levels of staff turnover. These conditions limit the
technical support that can be given to farmers.
The financial difficulties of the Honduran
government constrain the budgetary resources
available for aquaculture. Frequent reorganizations and
limited operating funds weaken the efforts of the
regional aquaculture offices, exacerbating widespread
distrust and skepticism about governmental services.
One large private university has been a consistent
source of training and fingerling supply for producers
in central Honduras. Public universities provide some
graduates and research support, but shrinking budgets
greatly limit the programs that can be offered.
In Rwanda, ethnic conflicts have swept aside
much of the progress made in aquaculture over the last
two decades. Assuming peace and public confidence
can be restored in the short term, the need and potential
for aquaculture success is clearly present. The
University of Rwanda has facilities and programs to
provide trained aquaculture graduates. The
government's limited ability to make a financial
commitment to aquaculture makes the likelihood of any
broad initiative for extension to be low. In contrast,
farmer interest and enthusiasm for aquaculture is high.
The data in this study and in previous reports show
that new farmers are adopting the enterprise without
extension prompting and some farmers provide
fingerlings to their neighbors. Although the practice of
aquaculture in Rwanda has been at a low level of
technical proficiency the need is much greater in this
country than the others and the rate of change in the
status of fish culture has been much faster.
Farmers were asked about the main things
preventing larger harvests. Honduran farmers noted
"my understanding" as the 
major obstacle to obtaining
larger harvests from their ponds. Water quality was the
biggest issue in Thailand and the Philippines, an issue
referred to simply as "the pond" in Rwanda. Manure
and compost availability was the obstacle most
frequently cited in Rwanda. These findings underscore
the significant contribution of PD/A CRSP research
activities toward the demystification of the pond as a
growth environment for fish. Productivity advances for
the majority of family farm operators will stem from
basic understandings of the pond system that will
diminish the risk of crop loss and enhance yields from
a given set of resources. Many of the basic parameters
of fish culture have been established in useable form;
the translation and dissemination of these principles
remains a daunting task.
PD/A CRSP RELATIONSHIPS TO GOVERNMENT
AND INDUSTRY
Aquaculture succeeded in Rwanda because its
diffusion was properly supported during an extended
period of peace in the countryside. The technology was
appropriate to the setting and it met critical needs for
cash income, nutrition, food security, and enterprise
diversity. A widespread network of hatchery stations
provided fingerlings and demonstrated good
aquaculture practice. A well-trained and motivated
cadre of extensionists made visits to farmers. Producers
found ready markets for their fish among their friends
61
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
and neighbors, as well in organized markets in towns
and urban centers. The PD/A CRSP provided sound
science and organizational guidance to an extension
network that provided an extended period of support
to individuals and groups beginning the practice of fish
culture. The ethnic unrest that troubles Rwanda, and
much of Africa, in the 1990s presents obstacles to
aquacultural development.
In Honduras, the PD/A CRSP effort was well-
positioned to contribute to the development of national
institutions, but the location was far from the North
Coast areas where a large-scale tilapia industry is
established. A solid research program and a wide
network of interpersonal and interorganizational
contacts multiplied the impact of the research program.
High personnel turnover and weak institutions muffled
the impact of PD/A CRSP technology on the farm level,
though the success of key alumni of PD/A CRSP
training programs keep the promise of fish culture alive
among farmers.
The Philippine PD/A CRSP contributed to
baseline research on tilapia production issues, but the
impacts of the PD/A CRSP program in this country
are largely overshadowed by the efforts of ICLARM
62 and the British Overseas Development Agency 
(ODA)
that have had a sustained presence of personnel in the
country and much larger budgets for conducting
research. PD/A CRSP efforts have been extensively
leveraged by the extensive network of United States -
trained personnel and their interest in the PD/A CRSP
program. PD/A CRSP ties to large-scale tilapia
production are weak or nonexistent in the Philippines.
Nonetheless the project has been a beneficial influence
on the national research program conducted in the
nation's main tilapia production area.
The Thailand PD/A CRSP was best positioned
to conduct high-quality, world class research. The Asian
Institute of Technology provided a supportive, if
expensive, environment for the conduct of experiments
and data analysis. The presence of other aquaculture
researchers and a small cadre of aquaculture social
scientists augmented the impact of the PD/A CRSP
program by providing ties to other projects in other
parts of the country. Other projects provided baseline
social data about tilapia producers and access to
technology transfer mechanisms otherwise unavailable
to the PD/A CRSP. The extensive network of industry
contacts maintained by PD/A CRSP researchers also
multiplied the influence of PD/A CRSP research efforts
TECHNOLOGY TRANSFER
When we refer to PD/A CRSP technologies,
we are primarily considering experimentally-based
information about feeding and fertilization. The PD/
A CRSP has done extensive work in each nation
detailing optimum paths to tilapia production using
the predator species, growing conditions, and input
materials found in each setting. The technology transfer
process is at core a series of communication steps that
relay new findings and perspectives to technical
representatives in government research and extension
systems, as well as to hatchery managers and others in
commercial sector roles that feature regular contact with
tilapia growers.
It is intended that the framework developed
in this study be sufficiently general to be applied at all
PD/A CRSP sites, yet sufficiently flexible to allow the
inclusion of site-specific variables and other
considerations. We endeavored to obtain basic
production, marketing, labor, input supply, and
farming system information from potential adopters of
PD/A CRSP-related technologies. Based on primary
data from farmer interviews, secondary data from PD/
A CRSP researchers, and other sources, we are led to a
number of basic observations about the transfer of PD/
A CRSP findings to national institutions and to
individual farm operators.
The primary impacts of the PD/A CRSP project
are channeled through interpersonal processes. PD/A
CRSP scientists interact with station personnel, sharing
insights and perspective on the technology of
aquaculture. These influences are then retransmitted
to farmers and 
others who have 
contacts with 
station
personnel, particularly if the station personnel have
training or leadership roles. Through interpersonal
contacts, PD/A CRSP scientists impart a holistic
understanding of pond dynamics and fish behavior that
is difficult to obtain through the printed word or other
formal means.
PD/A CRSP scientists have had direct impacts
on farm practice through the various training sessions
that research stations have sponsored over the years.
The production recipes conveyed directly to farmers
in these programs often have had dramatic impact in
the operations of receptive individuals with the
ingenuity and motivation to realize the promise of the
enterprise. The effect of personal relationships between
farmers and PD/A CRSP scientists should not be
underestimated. In turn these individuals influence
on the burgeoning Thai aquaculture industry.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
their neighbors by example and interaction over the
proper practice of fish culture.
Another communication channel for PD/A
CRSP findings is through written publications. Journal
articles and meeting presentations convey research
results to the scientific community. Reprints may
circulate among some institutional participants in the
host country, but rarely do they reach the farm level.
Findings of this sort require two sorts of transformation
on two levels; one, accumulation and reconstitution to
become user-robust recommendations, and two,
translation to the spoken language of the user. On both
fronts we observe an opportunity to improve the impact
of the PD/A CRSP.
Applied research reports translated into the
local language are not extensively found in the PD/A
CRSP corpus. Although a number of sporadic and
situational efforts have been made to produce
illustrated handbooks or pamphlets in the local
language, the legacy is not extensive. Most research
reports have been issued solely in English, most often
without national language executive summaries or
abstracts. These translated preambles are important for
non-native English speakers because the translation
provides context and meaning for the more detailed
findings presented in the document it precedes.
Video cassette recorders are becoming a
pervasive part of life in each PD/A CRSP country.
Unlike some international projects, the PD/A CRSP has
yet to develop video presentations of its findings and
research program that could be used in meetings with
technical staffs and progressive farmers in each of the
countries. These videos could be prepared in English
with separate voice and music tracks for ready
rerecording of narrative into local languages and
possible use in other countries.
We observe an opportunity for PD/A CRSP
support of a host-country national at each site to serve
a training and communication function for fish farmers.
There has been very indirect and limited impacts of PD/
A CRSP research findings on farm level practice. The
primary effects of the PD/A CRSP experimental
program have been on national systems through
interaction with national scientists, program managers,
and extension personnel.
It is understandable that one or two scientists
responsible to an annual work plan and experimental
program have little time or resources to expend on
applied publications or extensive direct participation
in staff or farmer training. However, these are the
fundamental mechanisms for extending PD/A CRSP
results to the farm level and realizing the socioeconomic
benefits of fish culture to individuals, families, rural
communities and the national economy.
FINANCIAL ANALYSIS
One objective of this study was to determine
the costs and returns associated with alternative
production regimes specified by the PD/A CRSP
workplan to establish a baseline profile of financial
profitability per system per country.
In Honduras, previous research has established
a model for integrating economic and financial
information in assessing the viability of different ways
of growing tilapia. Using economic information on
nutrient-input tilapia production regimes provided by
PD/A CRSP researchers, an examination of the various
strategies was made. The PD/A CRSP research shows
that fertilization could profitably supplant feeding for
a significant part of the tilapia's growth cycle.
The relevant data for each site's experimental
regime was concatenated into a comparable analytic
framework. Comparisons and analysis of production
relationships and adopter incentive structures were
made. Economic viability was assessed with published
PD/A CRSP experimental results and recent data about
input costs. These data show the relative profitability
of various combinations of feeds, fertilizers, and
production systems.
..Econometric analysis of production inputs and
outputs can help determine economically optimal
production paths to.maximum profit. The partial net
returns from many PD/A CRSP experiments showed
that the greatest production was not necessarily
associated with the highest return. These ideas about
the production and profitability relationship need to
be furthered through incorporation of economic data
collection on PD/A CRSP field trials.
A system of collecting quantitative input data
at the farm-level using PD/A CRSP technologies is
needed to learn optimal efficiency levels. Input
information on stocking rates and amount harvested
is usually possible without problem. However,
systematic monitoring of nutrient and fertilizer inputs
by farmers has proven very difficult to accomplish, but
must be collected for future econometric analysis of
production.
63
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
Some stocking rates in the survey results were
higher than those used in the PD/A CRSP experiments.
In more recent PD/A CRSP workplans than are
analyzed here, stocking densities have been increased
to two and three fish per m
2
. Further increases in
stocking rates need to be conducted to find optimal
tilapia stocking rates for farmers. Again, given sufficient
data, production function models can be developed that
can identify economically viable stocking rates.
The survey results show that most farmers use
a diverse combination of vegetative inputs, manures
and livestock feeds. Concentration on one input with
supplementation from one of the other categories is the
norm. Farmers seem to organize their tilapia enterprise
around an existing resource or under-utilized input.
The tilapia enterprise is most often valued as a
complement to an existing farm activity (such as
poultry), especially among small- and medium-scale
operators.
PD/A CRSP research has tested the use of low,
high and combined levels of feed and fertilizer (organic
and inorganic) inputs and could play a leading role in
tilapia farming development by getting this
information out to farmers. Field tests and data
64 collection, as described above, could further clarify the
profitability and risk of these technologies to farmers.
Where PD/A CRSP activities have the
opportunity to influence host country governmental
assistance to aquaculture, efforts should emphasize
infrastructure development. Poorly organized fish
product markets and input distribution systems often
hinder aquaculture development. As markets for tilapia
expand, production and support services will also
expand. Development of private sector marketing
services for both production inputs and fish outputs
will be needed for sustained aquacultural development.
FINGERLING PRODUCTION
Fingerling production is often the most
profitable, but also the most risky and complex, phase
of aquacultural production. The development of private
sector fingerling suppliers is a primary step toward
sustainable aquacultural development. If the public-
sector is used as an initial aquaculture catalyst,
government efforts could initiate the supply of
fingerlings, but should not continue to supply seed
stock at subsidized prices.
Although primarily an issue in Honduras,
government hatcheries need to gradually increase
fingerling prices to cover all production costs. More
efficient private fingerling producers can then develop
in a competitive market. This action will increase
competition and stimulate private-sector fingerling
production. Nonetheless, government stations have an
important role in maintaining and improving
broodstock, conducting applied research, and
coordinating information exchange in the absence of
effective extension programs.
We observe a need for better understanding of
private sector hatchery operations and their role in
aquaculture development and technology transfer. In
all four countries, the purchase of fingerlings is a
significant opportunity for contact with producers.
When government stations are the main source of seed
stock for fish farmers, fingerling sales approximate field
days or organized events that present opportunities to
communicate with assembled groups of fish farmers.
In Thailand, however, the private sector infrastructure
for fingerling production has matured to the point that
many dispersed fingerling suppliers have regular
contacts with local sets of farmers.
The fingerling suppliers themselves then
become an important target group for extension
because of their regular, direct interactions with
farmers. Private hatchery managers often provide
informal advisory and diagnostic services to their
customers, if only to maintain the reputation of their
seed stock against competing sources. In Rwanda,
similar (albeit less formal) processes were at work.
Fingerling sales by farmers to their neighbors also were
mechanisms for transmitting basic information and
instruction to new producers.
Information distribution is the one support
service that may be difficult for the private sector to
provide effectively to small-scale producers. Large-scale
private firms have effectively transferred production
inputs and information to contract farmers. However,
contract farming has been likened to agricultural
serfdom, where the farmers are not well-paid, make
few production decisions, and control resides in the
hands of a few large companies. Vertical integration
may not be the best developmental path to encourage,
although it may be the most rapid route to high levels
of fish production.
Finally, aquacultural development will be more
sustainable if fish production technologies have low
economic risks to the farmer. Baseline PD/A CRSP and
farmer fish production data need to be analyzed for
risk levels and strategies developed to lower such risks.
Economic indicators can be useful in helping
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
researchers to fine-tune technologies to improve the
likelihood of farmer acceptance and long term
sustainability.
REPRISE: IMPACTS OF THE PD/A CRSP
One common pattern across the four PD/A
CRSP sites considered here is the upstream nature of
the PD/A CRSP contribution to technology transfer.
Although farmer trials have been conducted at one time
or another in each site, these efforts largely have been
singular or specialized events and not part of a
systematic program. In none of the countries do farmers
now have a regular pattern of contact with a private or
governmental technology transfer agent. What limited
efforts are underway tend to have only sporadic and
indirect communication ties to PD/A CRSP researchers
and host institutions.
Farmers rely heavily on word-of-mouth and a
melange of information sources and experiences most
of which have little connection to the PD/A CRSP. In a
small nation like Rwanda with little institutional or
private-sector development in aquaculture, the PD/A
is a central and influential actor in the advance of
aquaculture. In a more-developed, dynamic, and
institutionally rich context such as Thailand, the PD/
A CRSP is but one of many sources of research,
technology, and practical assistance.
Most of the farm-level impact of PD/A CRSP
activities is second order; that is, PD/A CRSP research
information is absorbed, integrated with other
messages, and retransmitted by private firms and
national institutions. The messages are received by
innovator farmers, private managers, hatchery
personnel, trainers, consultants, and others who will
use the information to make decisions about growing
fish. The messages also affect what these individuals
tell others who want to or already are raising tilapia.
The most immediate impacts of PD/A CRSP
activities are manifested primarily in the training
experiences of degree candidates at institutions of
higher learning such as the Asian Institute of
Technology, University of Rwanda, Zamorano
University, or Central Luzon State University. PD/A
CRSP personnel serve as thesis advisors or consultants
for faculty and students conducting aquacultural
research or have other ties with these institutions. The
insights, paradigms, organizing frameworks, and
scientific technique communicated during these
activities represents a major technology transfer impact
of the PD/A CRSP.
In each country, PD/A CRSP researchers have
direct contacts with extension or outreach staff working
in fish culture. The collegial relationships, information
exchanges, mutual assistance, and other forms of
mutual influence also are a means for furthering the
influence of PD/A CRSP research. In a manner that is
often diffuse and subtle, but occasionally direct and
focused, PD/A CRSP research operations and research
findings contribute to the information milieu
surrounding each nation's aquaculture industry.
Extension programs and the training of
extension personnel are only indirectly influenced by
the PD/A CRSP. In the Philippines, village-level
extension in aquaculture does not exist. It is at best
highly variable in the other nations. Even in Thailand,
with the largest and best-developed network of
personnel and facilities devoted to fish culture, PD/A
CRSP ties to extensionists are infrequent and weak.
The many institutional actors working in
aquaculture perhaps should be considered the primary
audience for a global research project such as the PD/A
CRSP. Although some level of direct farmer contact and
training is necessary for keeping PD/A CRSP scientists
in touch with the direct experiences and problems of fish
farmers, the impacts and influence of the PD/A CRSP
may be greater if institutions and industry are understood
to be the primary consumers of PD/A CRSP outcomes.
Thus, seminars for nongovernmental
organizations (NGOs) that maintain extensive and long-
term relationships with villages and small-scale farmers
may be a more effective mechanism for reaching this
constituency than direct intervention by the PD/A CRSP.
As long as small- and medium-scale farmers remains a
central target segment for PD/A CRSP research impacts,
the development of a continuing network of contacts
with representatives of these groups will be a significant
objective for the PD/A CRSP. The NGOs may be more
effective at stimulating interest and reaching small-scale
farmers than governmental organizations or the limited
and sporadic activities of PD/A CRSP personnel (38).
To gain greater leverage for PD/A CRSP
activities, a number of strategies might be consciously
highlighted for PD/A CRSP scientists. These include;
instructing NGO trainers, encouraging NGOs to adopt
aquaculture as part of their repertoire of assistance
activities, and helping national institutions organize
seminars and training programs for NGOs. These and
other means may be used for wholesaling PD/A CRSP
technology to actors closer to village life who will be
there when PD/A CRSP is not.
65
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
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Environments.
(64) Tendler, J. 1993. "Tales of Dissemination in
Small-farm Agriculture: Lessons for Institution
Builders." World Development 21:1567-1582.
(65) Wattanutchariya, S. and T. Panayoutou. 1982.
"The Economics of Aquaculture: The Case of Catfish
in Thailand." Chapter in Proceedings No. 11,
Aquacultural Economics in Asia. Manila, The
Philippines: International Center for Living Aquatic
Resource Management.
(66) World Bank. 1991a. Fisheries and Aquaculture
Research Capabilities and Needs in Asia. World Bank
Technical Paper No. 147, Fisheries Series. Washington,
D.C.: World Bank.
(67) World Bank. 1991b. Fisheries and Aquaculture
Research Capabilities and Needs in Asia. World Bank
Technical Paper No. 149, Fisheries Series. Washington,
D.C.: World Bank.
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
APPENDICES
APPENDIX TABLE I. FARM ENTERPRISES PROVIDING MOST CASH INCOME BY SIZE OF
POND AREA, HONDURAS, PHILIPPINES AND THAILAND, 1994.
Farm 
Honduras Philippines 
Thailand
enterprise All 
Small Medium 
Large Small Medium 
Large Small Medium 
Large
Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct.
Vegetables 32 71 39 33 60 35 7 18 - 13
Rice 34 - 8 - 80 50 33 71 38 6
Bananas 16 - 8 - 15 20 - 47 19 31
Fruit crops 28 - - 7 20 50 7 77 31 50
Fish 73 12 46 40 80 85 100 100 100 94
Sugar cane 3 6 - - - 10 -
Livestock 40 41 15 40 25 30 20 71 75 44
Corn 8 24 8 13 15 10 - - - -
Other 3 - -- 15 10 - - - -
(Responses) (357) (26) (16) (20) (62) (60) (25) (65) (42) (38)
(Cases) (151) (17) (13) (15) (20) (20) (15) (17) (16) (16)
1 Column percentages will be greater than 100 because of multiple responses given by each respondent.
APPENDIX TABLE II. CAPITAL EQUIPMENT PRESENT BY SIZE OF POND AREA,
HONDURAS, PHILIPPINES AND THAILAND, 1994.
Equipment Honduras 
Philippines Thailand
item All Small Medium Large 
Small Medium Large Small Medium Large
Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct.
Truck 47 77 53 80 5 15 33 53 69 47
Seine net 65 71 59 80 75 95 87 18 38 59
Water quality kit 3 - 6 7 - 18
Water pump 64 18 24 13 55 75 100 100 94 100
Aerator 1 7 - - -
D.O. meter 1 - - 7 - - - - - -
Weighing scale 87 82 77 87 75 85 87 100 100 100
Wheel barrow 62 100 94 80 25 25 27 53 75 88
(Responses) (513) (59) (53) (53) (47) (59) (51) (55) (60) (70)
(Cases) (156) (17) (17) (15) (20) (20) (15) (17) (16) (17)
APPENDIX TABLE III. WATER AVAILABILITY AND SOURCES FOR AQUACULTURE BY SIZE OF POND AREA,
PHILIPPINES, HONDURAS AND THAILAND, 1994
Country and 
Problems 
Primary water 
source
pond size gettin Irrigation Combination
2  
River or Spring Collected Well
category water canal stream runoff
Pct. Pct. Pct. Pct. Pct. Pct. Pct.
Philippines
Small 50 10 20 5 5 35 25
Medium 25 20 45 15 10 10 0
Large 27 0 63 25 6 0 0
Honduras
Small 18 0 18 47 29 0 0
Medium 24 0 6 56 13 0 6
Large 13 0 7 40 13 0 13
Thailand
Small 71 88 6 0 0 6 0
Medium 50 44 50 6 0 0 0
Large 41 53 47 0 0 0 0
1 Response to the question, "Have you had problems getting enough water to keep your pond filled?"
2 Combination water sources for the Philippines included collected runoff, well stream and 
irrigation canal water.
69
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
APPENDIX TABLE IV. MAIN SOURCES OF NUTRIENT INPUT BY SIZE OF POND AREA,
HONDURAS, PHILIPPINES AND THAILAND, 1994
Nutrient 
Honduras Philippines 
Thailand
source 
All Small Medium 
Large Small Medium 
Large Small Medium 
Large
Pct. Pct. Pct. Pct. Pct. Pctg. Pct. Pct. Pct. Pct.
Kitchen wastes 5 32 6 - - 3 - 19 5 5
Vegetation 10 26 6 16 3 3 3 19 12 12
Rice bran 24 11 19 16 42 30 27 14 24 26
Dead animals 1 - 2 7
Slaughter wastes 1 5 6 - - - - 5
Commercial feed 21 26 44 62 6 16 30 35 12 9
Chicken litter 16 - - - 18 19 23 - 17 21
Inorganic fertilizer 22 - 19 8 30 30 17 8 29 21
(Responses) (278) (19) (16) (13) (33) (37) (30) (37) (42) (43)
(Cases) (136) (11) (11) (11) (18) (20) (16) (24) (16) (16)
APPENDIX TABLE V. TYPES OF COMMERCIAL FEEDS AND FERTILIZER PURCHASED BY SIZE OF POND AREA,
HONDURAS, PHILIPPINES AND THAILAND, 1994'
Nutrient 
Honduras 
Phiippines 
Thailand
source All Small Medium 
Large Small Medium Large Small 
Medium Large
Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct.
Feeds:
Rice bran 25 6 18 20 30 20 25 18 50 41
Rabbit feed 3 6 12 7 - - 6 -
Chicken feed 3 6 6 7 - 5 - - - 6
Fish feed 28 29 12 33 20 25 50 47 31 12
Fertilizers:
Urea 21 29 53 40 15 5 25 6 19 6
0-46-0 3 - - - - - - 6 19 6
18-46-0 4 - 18 13 - - 6 - -
-
Chicken manure 52 24 47 20 70 70 69 47 44 71
Cattle manure 15 47 24 40 - - 13 6 6 6
Compost 9 - - - 5 - - 6 31 41
Other fertilizer 52 41 24 7 85 80 69 35 69 53
(Responses)
Feeds (942) (102) (102) (90) (120) (120) (120) (102) (96) (102)
Fertilizers (1256) (136) (136) (120) (160) (160) (128) (136) (128) (136)
(Cases)
Feeds (157) (17) (17) (15) (20) (20) (16) (17) (16) (17)
Fertilizers (157) (17) (17) (15) (20) (20) (16) (17) (16) (17)
'Column percentages will be greater than 100 because of multiple responses given by each respondent.
70
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
APPENDIX TABLE VI. TYPE OF ANIMALS RAISED WITH FISH BY SIZE OF POND AREA, HONDURAS, PHILIPPINES AND
THAILAND, 19941
Animal All Honduras Philippines Thailand
Small Medium Large Small Medium Large Small Medium Large
Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct.
Animal-tilapia 45 29 35 13 38 28 57 65 80 63
integration
Cows 37 69 39 82 35 32 27 15 - 33
Goats 14 6 - 9 25 32 40 - - -
Hogs 40 63 54 18 60 37 27 46 17 25
Chickens 68 81 69 55 90 79 67 62 42 50
Ducks 29 19 15 27 25 32 40 31 50 33
Rabbits 2 6 8 - - - - - - -
Other 26 13 15 9 45 53 53 15 8
(Responses) (288) (41) (26) (22) (56) (50) (38) (22) (14) (17)
(Cases) (133) (16) (13) (11) (20) (19) (15) (13) (12) (12)
Column percentages will be greater than 100 because of multiple responses given by each respondent.
APPENDIX TABLE VII. STOCKING DENSITY BY SIZE OF POND AREA, HONDURAS, PHILIPPINES AND THAILAND, 1994
Stocking All Honduras 
Philippines Thailand
density Small Medium Large Small Medium Large Small Medium Large
No./m
2  
Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct.
1.1 or less 12 23 - 18 25 6 8 7 7 1
1.1-1.5 6 15 7 27 - 6 8 - -
-
1.6-2.0 14 8 57 27 13 6 8 - 13 -
2.1-3.0 16 39 7 27 19 11 17 - 7 11
3.1 - 4.0 15 - 29 - 13 30 8 13 20 11
4.1-5.0 11 - - - 13 18 17 13 34 -
5.1 - 6.0 4 - - - 6 - - 13 7 6
6.1-7.0 4 - - - 6 6 - 7 7 6
7.1 - 8.0 8 - - - 6 - 17 27 7 11
8.1-9.0 - - - - - - - -
- -
9.1-10.0 5 8 - - - 6 8 - - 18
> 10.0 9 8 - - - 6 8 20 7 24
(Number) (157) (13) (14) (11) (16) (17) (12) (15) (15) (17)
71
SOCIAL, ECONOMIC, AND INSTITUTIONAL IMPACTS OF AQUACULTURAL RESEARCH ON TILAPIA
APPENDIX TABLE VIII. PRODUCTION CYCLE LENGTH, CROPS PER YEAR, AVERAGE HARVEST WEIGHT AND HARVEST
STRATEGY BY SIZE OF POND AREA, PHILIPPINES, HONDURAS AND THAILAND, 1994
Country & Days in Tilapia crops/year Average size Harvesting strategy'
Pond Size
Category cycle One Two Three harvested Partial Partial+1 Single
No. Pct. Pct. Pct. Gm. Pct. Pct. Pct.
Honduras
Small 194 41 53 6 274 24 35 41
Medium 263 67 27 7 275 33 13 53
Large 235 53 40 7 570 47 20 33
Philippines
Small 145 39 61 0 173 80 13 7
Medium 149 21 68 11 199 74 16 11
Large 139 13 69 19 179 50 36 14
Thailand
Small 307 83 17 0 328 0 13 87
Medium 346 100 0 0 301 0 15 85
Large 358 100 0 0 411 12 24 65
1 Harvesting strategies include: Partial - partial harvesting; Partial+1 - partial harvesting and one large harvest at
end of the cycle; Single - one large harvest at the end of the cycle and NO partial harvesting
APPENDIX TABLE IX. WEIGHT CLASS OF INDIVIDUAL FISH HARVESTED BY SIZE OF POND AREA,
HONDURAS, PHILIPPINES AND THAILAND, 1994
Size of All Honduras 
Philippines Thailand
harvested fish Small Medium Large Small Medium Large Small Medium Large
Gm. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct.
< 100 6 13 - - 11 11 25 - --
100-200 30 31 32 - 56 58 50 14 - 6
201-300 31 25 38 27 33 16 19 29 64 18
301-400 16 6 13 27 - 16 - 14 29 41
401-500 11 19 13 13 - - 6 21 7 18
501-600 1 - 6 .......
601-700 2 6 - 7 ..... 6
701-800 1 ...... 7 - 6
801-900 1 - - 7 ..... 6
901-1000 0 .........
> 1000 3 - - 20 -.....
(Number) (147) (16) (16) (15) (18) (19) (16) (14) (14) (17)
APPENDIX TABLE X. DISPOSITION OF TILAPIA HARVEST BY SIZE OF POND AREA,
HONDURAS, PHILIPPINES AND THAILAND, 19941
Item All Honduras Philippines Thailand
Small Medium Large Small Medium Large Small Medium Large
Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct. Pct.
Sold tilapia 87 80 88 100 94 100 100 100 100 100
last harvest
Sold to:
Middlemen 69 19 50 80 55 84 100 93 93 93
Restaurants 13 13 31 47 - 5 19 7 -
Marketplace 14 13 - 13 39 32 19 7 -
Other buyers 70 88 75 87 89 63 69 79 50 50
(Number) (11) (15) (16) (15) (18) (19) (16) (14) (14) (15)
Column percentages will be greater than 100 because of multiple responses given by each respondent.

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