This book is the proceedings of the “Regional Consultation on Culture-Based Fisheries Development in Asia”, held in Siem Reap, Cambodia, 21-23rd of October 2014, under the auspices of the Australian Centre for International Agricultural Research (ACIAR), the Mekong River Commission (MRC) and the Network of Aquaculture Centres in Asia-Pacific (NACA). The consultation was jointly organised by NACA and the Fisheries Administration of the Royal Government of Cambodia.
Food and nutritional security remains problematic in many developing countries. There are many initiatives underway which are designed to increase food supply, employment and income opportunities, most of which require considerable capital inputs (for instance cropping, livestock production and aquaculture). Often overlooked, are the opportunities to produce more food from the natural productive ecology of lakes and forests. Culture-based fisheries are one example of a relatively simple and low cost technology which can deliver nutritional and economic benefits to communities which often have few livelihood options.
Culture-based fisheries are based in lakes and reservoirs, where fish populations are supplemented by hatchery-produced fingerlings. The stocked fish may breed naturally in the lakes, or they may be species which are desirable but which do not breed in the still-water environments. Fish growth is driven by the natural productivity of the water bodies. Generally, local communities have ownership of the fish, with the benefits shared or used for communal purposes. However, there are other options for management and ownership depending on local needs, cultural arrangements and other uses of the water.
Research and development of culture-based fisheries has been a major endeavour for NACA and ACIAR since the mid-1990s. This has involved projects in Sri Lanka, Indonesia, Vietnam, Lao PDR and Cambodia, the results of which have been reported in previous publications, as noted below. In this volume, we bring together an update from research conducted in those countries and others. We trust the information will foster further development and spread of culture-based fisheries in Asia and beyond, and in doing so, bring livelihood and nutritional benefits to otherwise resource-poor communities.
NACA publishes technical papers and manuals for a wide variety of farming systems and related environmental and social issues. Many of these provide guidance on better management practices with a view to improving crop outcomes and on-farm resource utilisation efficiency. By using inputs such as feed and power more efficiently, farmers can simultaneously improve their profitability and environmental performance.
CBF is essentially a stock and recapture strategy, where the stocked fish feed and grow on naturally produced food resources, and which are most effective when communally managed. The returns from CBF could be very significant in terms of nutritional as well as monetary benefits to the communities. In this presentation the relevant background information on food fish needs and the ways and means of introducing CBF practices in inland waters are dealt with.
In recent years, stocking programs have been subjected to substantial criticism due to perceived impact of hatchery-bred fish on genetic structure and fitness of wild stocks, transfer of disease, introduction of exotic species and non-target species, and their effects on other aquatic species and the environment. To maximise the potential benefits to fisheries from stock enhancement a responsible and ecologically sustainable approach should be adopted for all stocking programs.
A shift away from exotic speces towards the use of indigenous ones was believed to counter negative impacts of culture-based fisheries. However, hatchery-produced fingerlings can also pose a potential threat to genetic diversity and integrity of their wild counterparts. This paper entails the pros and cons in the use exotic vs. indigenous species in CBF and steps to be followed when decisions are made on species choice for CBF.
A summary of culture-based fisheries developments in Lao PDR based on publications, either in the primary literature, or as manuals and reports posted on the website of the Network of Aquaculture Centres in Asia-Pacific, that have originated from projects funded by the Australian Centre for International Agriculture research (ACIAR) since 1997.
The application of culture-based fisheries in Cambodian waters commenced with a project in sixteen small reservoirs located in four provinces. Initial consultations with the village communities responsible for the water regime management were held and their agreement obtained for monitoring and cooperating through the trial period. One common feature in all the reservoirs selected is the provision of a “conservation zone”, generally in the deeper areas of the water body, where fishing is prohibited.
Culture-based fisheries in village reservoirs of Sri Lanka is a communal activity involving agricultural farmers without prior experience in fisheries. Awareness programs have facilitated establishment of CBF in small village reservoirs. Dissemination of research findings through means such as production of a documentary film, publication of a monograph which was translated to several regional languages, and holding a series of regional workshops were instrumental for CBF development at the regional level.
Fish stocking in Indonesian lakes and reservoirs has been conducted for a long time. Since 1999, culture-based fisheries (CBF) practices based on scientific evidence such as using suitable fish species, consideration of the primary productivity, stocking density, economic evaluation and community participation, have been conducted in some reservoirs and lakes and have showed encouraging results. CBF is highly recommended and prioritised in small reservoirs with an area less than 200 ha.
Sri Lanka is blessed with a large number of irrigation reservoirs. Culture-based fisheries (CBF) in seasonal reservoirs was initiated in the 1980’s and the government has recognised CBF as an effective way of increasing fish supplies in rural areas, at affordable prices, while providing employment and income to farmers and thereby contributing towards alleviation of poverty. The role of fisher community based organisations and fisheries management for effecting successful CBF are discussed.
Releasing of giant freshwater prawn (Macrobrachium rosenbergii) for the purposes of stock enhancement and to create a fishery has been conducted in Thailand since the 1980s. Average age at harvest is around 6 to 8 months, with an average total length of 20 cm. Overall, the success of stocking M. rosenbergii is poor since the recapture rate is generally less than 5 %. However, the economic return is high.
In this paper, the culture-based fisheries in lakes are presented, with special reference to mandarin fish and mitten crab stocking in lakes in China. The stocking rate of mandarin fish is determined by food consumption rates, which are mainly related to water temperature and fish size, and prey fish productivity. A bioenergetics model of mandarin fish was established to predict the growth and consumption of prey fish in stocked lakes.