Meeting the needs of the poor in Asia-tilapia in the New Millennium

David C. Little1,

1Institute of Aquaculture

University of Stirling

Stirling, FK9 4LA,UK

Abstract

Tilapias are currently having important impacts on poor people in developing countries, both as cultured species in household-managed systems and through access to fish produced in informal and formal fisheries. Key constraints include a lack of consistent quality seed, a shortage of nutrient inputs and, in some cases, undeveloped markets. A modified framework for tilapia production is proposed with the aim of understanding the possible outcomes of further promotion of tilapia production on the poor in their role as producers, intermediaries and consumers.

The problems associated with promoting tilapia culture across a range of development contexts are important if institutions with this responsibility are to be successful in delivering sustainable benefits to producers and consumers. Many of these relate to both the positive and negative characteristics of tilapia reproduction, seasonality and the broader environmental and development context. Successful strategies also require understanding and acknowledgment of the relative failures of past attempts and the constraints that institutions face in supporting rural development.

Current status

The current importance of tilapia is typically under-reported in both national and international statistics because of its reproductive characteristics, government policy and a poor understanding of how the fish is valued and utilized. The ability of tilapias to reproduce without sophisticated intervention has been a major factor in its current distribution and importance. Unlike carps, it makes estimates of food fish based on the numbers of fish seed produced in central facilities impossible. This fact, coupled with the large percentage of tilapias that are often consumed in the home or marketed informally, makes most estimates of yield and their impact highly unreliable.

Once introduced the fish has typically filled a ‘niche’ in both ecological, production and dietary terms with many of the characteristics of a self-recruiting indigenous fish. No other type of introduced fish moves between household-managed and community wetlands in quite the same capacity (Figure 1) and this ‘duality’ is an inherent aspect of its both its current importance and future potential. We attempt to assess the current impact of tilapias and to document their key strengths and weaknesses in meeting peoples’ needs, especially the poorest. Trends in production, especially those towards intensification, are also analyzed for their potential impacts.

Systems

Type I tilapia production systems (Table 1) are clearly the most widespread and variable in terms of their productivity and importance and occur mainly in scattered rural locations. Yields can vary from less than 50kg. ha-1 to over 3 tonnes. ha-1. Typically poorer sections of the community can gain access to the fish on a periodic, seasonal or year-round basis and tilapias have substituted for, or added to, supplies of cheap freshwater and marine fish. The productivity of these systems tends to be constrained by lack of knowledge regarding best management practice, poor access to outside supplies of new germplasm and a lack of nutrients. Type II systems are characteristic of nutrient-rich peri-urban locations with good access to seed, information and markets. Yields range between 2-15 tonnes ha in such systems. Type III, industrial operations with integrated feed, seed and marketing, are becoming attractive investments to supply international markets. Production is less area-dependent in such systems as all feed is imported but yield can reach in excess of 100 tonnes. ha-1 in cage and raceway-based systems.

Impacts

Tilapias are currently meeting poor peoples’ needs in a variety of ways(Table 2); their importance needs to be assessed relative to that of other types of cultured fish and livelihood options more broadly. Poor producers benefit from lower entry costs and risk relative to other types of aquaculture. The performance of tilapias in small units, both cages and ponds, and in a range of fresh and brackish water environments has encouraged people already raising fish to substitute them for conventional species, and new entrants trying fish culture for the first time. The fish can be stocked within aquatic systems such as flooded ricefields, ditches, drains and ponds as a secondary product; the robust nature of tilapias allow them to thrive in a range of culture systems and environments at low risk compared to alternative species.

The marketability of tilapia at a relatively small size is a major advantage especially where low temperatures or lack of water curtails the production period. In Hanoi, Vietnam, tilapias have proved attractive because they reach their premium marketable size quicker than carps (Cao, 1998). The costs associated with overwintering may be higher than for carps however and the availability and cost of the nutrient inputs compared to a similar sized culture unit of carps is more problematic for resource-poor producers. Tilapias have proved to be more disease-resistant than many of the carps and catfish and their resistance to UDS was a major spur throughout Asia to their popularity for producers and consumers.

Major population trends towards a greatly increased proportion of the worlds’ poor living in peri-urban areas (UNFPA, 1999) highlights the need for both low-cost fish and disposal of organic wastes produced. An analysis of existing Type II systems suggests that tilapias produced in such systems have unique characteristics attractive to both producers and consumers. In addition to supporting peoples nutrition and income, tilapia production can contribute to hygienic waste disposal and improved sanitation (Edwards, 1992).

High productivity clearly does not necessarily result in improved outcomes for poor people, and in contrast benefits can be important even from relatively unproductive systems. In some rural areas where natural stocks have been devastated and aquatic systems are under constant environmental pressure, exotic tilapias are contributing to meeting ‘the hungry gap’. The low yields of small tilapias harvested from rice fields in the mountains of Northern Laos and ditches and canals of densely populated Central Luzon State, Philippines may be more critical for food security of the poor than fish produced through conventional aquaculture. In contrast, more intensive production can benefit local communities indirectly through improved availability of by-products, by-catch and local marketing opportunities.

The relative movement of seed, nutrients and products between the local, regional and national/international boundaries are useful descriptors for Types I, II and III. The degree of self-sufficiency of seed and nutrients at the producer level is also a useful indicator.

Expectations

Following the introduction of tilapias, their obvious virtues as cultured fish typically led both promoters and farmers to have unrealistic expectations. Decades later, and often following initial setbacks, tilapias are having important impacts on diets and incomes in a variety of countries. Cultured tilapias range from being considered mainly a cash crop in southern Vietnam, being valued both for consumption in the home and as a source of cash in the household (NW Bangladesh) to being raised mostly for subsistence needs (Northeast Thailand) (AIT, 20001,2,3).

A major constraint to the success of tilapia has been the widespread perception that self-sustaining stocks of tilapias deteriorate in quality over time, especially in small household-managed systems. The nature and primary cause of this deterioration often remains confused. Clearly, poor management of small founder stocks of mixed sex fish has often been a problem and frequently led to unfavourable characteristics developing over time. Poor quality has been a particular problem where contamination with feral strains has occurred, normally with Oreochromis mossambicus. This species was widely introduced in Asia, originally for its value as an ornamental (Pullin, 1988).

A key underlying reason for problems in sustaining the supply of quality tilapia to farmers is a failure by promoters to understand the implications of the tilapia’s distinct reproductive characteristics. Their low fecundity, aseasonal and asynchronous seed production, early maturation and sensitivity to low temperatures has confounded planners, particularly those used to carp-based aquaculture. A failure to meet expectations of both quantity and quality has been a frequent result.

Deterioration in ‘quality’ has come to be a major constraint, even among small–scale producers, if fish are primarily cultured to sell. The low value of tilapias produced in the sewage-fed culture systems of Tranh Tri near Hanoi, Vietnam before the recent introduction of new strains suggests the importance of maintaining or upgrading the quality of germplasm (Cao, 1998). The relative importance of, and constraints to, improving germplasm to benefit the poor and its relationship to hatchery development are discussed below.

Extensive approaches

An emerging paradox is the reliance of poorer people on ‘trash’ tilapia to meet food security needs, often following disappointment at the performance of tilapias, in commercial-orientated small-holder aquaculture,. This appears to be especially the case where the availability of other fish, especially small indigenous fish (SIS) or low-cost marine fish, has declined and tilapias have become established e.g. Philippines (Cheftel and Lorenzen, 1999), NW Bangladesh (Barman et al.,2000) . Such tilapias are often obtained from community waters as well as household-managed ditches, ricefields and ponds. Tilapias are particularly abundant in rice growing and coastal areas in which perennial water bodies are contiguous with large expanses of temporarily flooded fields and ponds. Such low quality, but saline-tolerant O. mossambicus are commonplace in coastal environments in Asia and are being used by the poor directly as food and as feed for livestock and fish production.

Elsewhere more conventional reservoir fisheries based on tilapias have become important, and sometimes dominant in meeting the needs of the poor. In Sri Lanka tilapias have no serious competitors as the fish of choice in freshwater systems. Attempts to stock the numerous inland tanks in with carps have largely failed and understanding the importance of self-recruiting tilapias has not been given adequate importance (Fernando, 1999).

A recent study of the marketing of tilapias in the poor Dry Zone suggests the current dominance of tilapias in the livelihoods of the poor (Murray et al., 2000 ). Fishers and itinerant traders tend to be marginalised people living in the countries Dry Zone and their activities support the nutrition of large numbers of poor in remote rural areas. Research has also indicated that the fishing pressure on these systems is often intense and that large numbers of these poor fishers and, in turn, consumers are at risk (Brugere and Pollock, 2000). The maintenance or improvement of the national yield of tilapia is of vital importance for Sri Lanka given trends in population growth and lack of alternatives but it is doubtful that intensive approaches will be profitable or practical. Improvement in the use of the large areas of seasonal ponds that are connected within cascading watersheds is a key need. Managing stocks of tilapias and indigenous fish within these systems, which are complex both physically and socially, appears to be the most adoptable and sustainable approach. In the Lao PDR it has been demonstrated that tilapias can be the focus for improved community management of water bodies, from which the yield and diversity of indigenous species can be enhanced (Garaway, 1999).

Characteristics of success

Where tilapia-based culture has developed most sustainably in Asia such as in southern Vietnam and Thailand, monoculture is rare. Rather, it has developed as part of a polyculture with carps and other fish in both rural and peri-urban areas. Often tilapias are of secondary importance to more valuable indigenous fish. Middendorp (1992) observed improved yields of the highly valued snakehead and other carnivorous species in rice-fish systems stocked with tilapias and Yoonpundh (1997) found them a frequent inclusion in large-scale commercial polycultures of the snakeskin gourami and other native fish in Central Thailand. In both cases stocking tilapia is a low cost, low risk option to increase overall yield of carnivorous fish, and as recruits are controlled, to produce a large more valuable tilapia.

Urbanization seems to be an important part tilapias realizing their potential. Trends towards greater availability of affordable cooking oil and less time for preparing and cooking fish by poor urban migrants appears to favour tilapias compared to alternatives. Small, deep fried tilapias are becoming a staple dish in many parts of urban Asia. A rapid survey in HCM City indicated that tilapias and other small freshwater cultured fish were most likely to be consumed by the poorest people. The opportunity cost of nutrient-rich wastes is also lower in peri-urban areas and farmers around Bangkok, Calcutta and Ho Chi Minh city in which carp culture is well established have gradually realized that higher yields and greater profits are possible if more tilapia are included in the polyculture

The expectations of people dependent on tilapias reflects the complexity of the modes through which tilapia has become established in Asia and elsewhere. Key issues include how the various characteristics of tilapia and tilapia production systems desired by beneficiaries might be further improved and if these are in conflict.

Limiting Factors
Nutrients

The critical limit to tilapia production in most contexts is poor early survival and a lack of nutrient inputs. As productive unmanaged systems have been established in many locations, despite the presence of piscivores, it can be assumed that the latter is the single most important factor. In many situations (I, II) the most cost effective approach to produce tilapia is through fertilization to stimulate natural food production in situ and supplementary feeding. Best strategies will consider the opportunity costs of both purchased and ‘freely’ available sources of nutrients. Both total and available nutrients must be considered and the ratio of the key nutrients nitrogen (N) and phosphorous (P) to dry matter is critical to maintain high levels of natural food and water quality. The relationship between total nitrogen and net yields is well established (Knud Hansen et. al.1992). Detrital food pathways are known to be important but in semi-intensive systems without mechanical aeration they are dependent on, and secondary to, phytoplankton production (Colman and Edwards, 1987).

Germplasm

The recent attention to improving the quality of germplasm of tilapias in Asia has tended to ignore several important factors. The first is the level to which the quality of currently available strains undermines performance of small-holder aquaculture compared to poor management. The lack of nutrient inputs appears to be a major constraint to small-holder aquaculture. The second is the degree to which tilapias have responded to the various types of selection pressures since their introduction over the last few decades. This form of selection could have had both positive and negative impacts on ‘quality’, which in itself is a subjective term. Thirdly, characteristics that could be positive for richer people may be negative for the poor. Features that are advantageous for the hatchery operator may be adverse for the food fish farmer, trader or consumer.

.Recent measures aimed at improving tilapias based on selection have concentrated on growth and survival in small cages (Eknath et al 1993). This is likely to have biased selection towards fish performing better in intensive systems and away from selecting animals capable of using low cost inputs in systems integrated within broader farming systems.

Selective breeding towards tilapias with better coloration, body form and carcass characteristics are likely to have broadly neutral impacts on poorer producers, providing improved seed and other inputs are accessible. However if strain development occurs under intensive husbandry conditions these could lead to the loss of characteristics favorable to resource-poor producers and consumers. Selection for improved tolerance to saline and cool water conditions seem likely to expand opportunities for poorer people to benefit from tilapia, especially as access to freshwater by poorer sections of the community is likely to decline as water resources come under increasing pressure. The virtual exclusion of the poor from brackish water environments in Thailand during the shrimp boom suggests that aquaculture entrepreneurs often monopolize such benefits leaving local poor people worse off however.

Intensification of tilapia culture-do the poor win or lose

Intensification offers both opportunities and threats to livelihoods of the poor. Outcomes may be both direct and secondary. They may affect people broadly such as through impacts on the wider environment, or specifically such as changing nutritional quality of fish produced and access to them. Key issues remaining include whether germplasm development can be targeted towards both commercial outcomes and address the needs of the poor? Can agribusiness, that typically both supports and stimulates the process, adopt practices that are pro-poor ?

The trend towards intensification, particularly type III industrial production, may have adverse impacts on the range of poor intermediaries that benefit in more integrated systems. Peri-urban production based on wastes provides a host of employment opportunities as well as having positive environmental impacts (Birley and Lock,.1997).