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Project Record

Objectives:

To characterise the role of self-recruiting species in different aquaculture systems, and to develop management approaches that enhance the production of and access to such resources by the poor.

Background:

Traditionally, aquaculture extension messages in rural Asia have sought to encourage production based on the use of hatchery-produced fish and other management inputs such as the sanitation of the culture unit, and optimal fertilisation, feeding and harvest strategies. This approach has allowed resource-rich farmers to intensify production and improve returns, but has not always been adoptable by poorer producers.

Recent research has highlighted the importance of self-recruiting species (SRS) in both natural and managed habitats to the livelihoods of the rural poor. As aquaculture continues to expand through the creation of new habitats and the enhancement of natural habitats and stocks, the availability of SRS will become increasingly linked to their production within aquaculture systems.

A range of indigenous and introduced fish species; as well as molluscs, crustacea and amphibians are inevitably present in many rural aquaculture systems unless deliberately eradicated.

The introduced tilapias, which tend to reproduce easily under pond conditions often play a similar role. Even under commercial culture conditions, small ,trash, fish, which are available to workers as payment in kind or are sold at low price may contribute to the livelihoods of poor non-fish farmers in rural and urban areas.

The importance of valuable, usually carnivorous wild fish species that typically enter fishponds in floodplain areas, in meeting farmers' needs is also now more appreciated.

Self-recruiting species may thus play an important role in the complex livelihoods of sections of the rural and urban poor. Aquaculture extension messages have so far not only ignored the importance of these resources, but often promoted management actions that have served effectively to reduce their availability.

Intended Outputs:

Role of self-recruiting species (SRS) in Asian aquaculture systems understood.

Importance of SRS from aquaculture systems in local livelihoods defined.

Management strategies defined to optimise benefits of SRS.

Dissemination and promotion to wider user base.

Progress and Impact:

1. Role of SRS in Asian farmer managed aquatic (aquaculture) systems understood.

This output has been achieved. A conceptual framework has been developed to aid classification and understanding of SRS systems.

2. Importance to livelihoods of SRS produced in aquaculture systems defined.

This output has been achieved. SRS have been shown to be important for poor people, both for home consumption and sale. SRS from farmer managed systems (ponds, ditches and rice fields) are most important in upland areas where other waterbodies are limited. Seasonally they are especially important during the dry season when access to other water bodies becomes limited. Value addition (drying, fermenting) is an important activity resulting from increased seasonal availability of non-stocked aquatic animals from farmer managed systems.

3. Management strategies defined to optimise production of and access to SRS within the livelihoods of the poor.

This output has been achieved. Management strategies have been investigated using observational, experimental and modelling approaches. Due to the strong linkages between large waterbodies and farmer managed systems, location specific group management shows promise in the maintenance and enhancement of SRS in poor communities. Specific technical interventions that have been identified as effective include keeping of broodstock, re-stocking of collected juveniles and the screening (or not) of pond entrances. Farmers who previously excluded SRS have observed that having SRS in the system does not negatively affect the production of stocked fish. The population dynamics of SRS and systems that rely on mixed SRS/stocked fish have been investigated theoretically and in field studies and management principles derived.

4. Dissemination of results and promotion of management and policy recommendations.

This output has been largely achieved. There has been substantial dissemination during the project. A proposal for a short project to further disseminate and promote outputs has been submitted to AFGRP.

Project Conclusions:

The substantial and long-overlooked role of farmer managed aquatic systems in sustaining wild fish stocks and fisheries has been documented. Management strategies for aquatic resources in farmer managed systems have been developed. A theoretical underpinning and practical assessment tools for the management of stock enhancements has been developed.

General Notes:

See also the TECA Records Management strategies to optimise production of and access to self recruiting species (SRS) within the livelihoods of the poor and Management of self recruiting species

Publications:

Lorenzen, K. and Enberg, K. (2002) Density-dependent growth as a key mechanism in the regulation of fish populations: evidence from among-population comparisons. Proceedings of the Royal Society of London Series B - Biological Sciences 269: 49-54.



Lorenzen K (2004) Population dynamics and potential of fisheries stock enhancement: practical theory for policy analysis and management. Philosophical Transactions of the Royal Society of London. In press.



Arthington A.H., Lorenzen K., Pusey B.J., Abell R., Halls, A., Winemiller K.O., Arrington D.A. & Baran E. (2004) River fisheries: ecological basis for management and conservation. In: Welcomme, R.L. (Ed.) Proceedings of the 2nd International Large Rivers Symposium. Vol. 1 pp. 31-60. Phnom Penh/Rome: Mekong River Commission/FAO



Bangladesh Journal of Fisheries Special Issue - June 2004 - The potential of SRS in aquaculture for sustaining the livelihoods of rural poor in Bangladesh