Farming experiments and transfer of technology of bivalve culture along the southwest coast of India

The Central Marine Fisheries Research Institute (CMFRI) in India developed bivalve farming technologies in the 1970s, but these were not widely adopted at the time. In 1993, CMFRI undertook an action research program to encourage farming of edible oysters (Crassostrea madrasensis), mussels (Perna viridis and Perna indica), clams (Paphia malabarica) and pearls (Pinctada fucata) along the southwest coast of India. Successful demonstration of the viability of bivalve farming led to the initiation of commercial farming of mussels and generated interest among farmers and entrepreneurs in developing production of pearls and farming of edible oysters. Given the high potential for the mollusc aquaculture, both for the local and export market, issues such as demarcation and issuance of lease right on aquaculture zones in public waterbodies by the government, organization of marketing systems and provisions for technical and financial support to farmers need to be addressed.

Community management of Mekong River resources in Laos

The Mekong River is one of Asia's greatest rivers. It is the lifeblood of millions of small-scale farmers and fishers in China, Burma, Thailand, Laos, Cambodia and Vietnam. In the Lao People's Democratic Republic (Lao PDR), the river is particularly important because for the landlocked country, the Mekong is the Sea of Laos. In southern Lao PDR, fisheries for native fish species constitute an extremely important source of subsistence protein and income for local people. It has been estimated that wild-caught fish constitute at least 90% of the protein for lowland Laotians living next to the Mekong. Despite the extreme importance of fish to the diets and economics of communities along the Mekong, the resource, and the people who depend upon it, are in danger.

Inland community fisheries in southern Laos

Since 1993, a series of aquatic resource co-management workshops have been on-going, established by the Lao government and fisheries agencies for village farmers in the Khong District in southern Laos, aiming for a sustainable use of inland capture fisheries resources. This article describes the mechanics involved and the participants' perspective, as well as reporting the outcomes and progress of the workshops so far.

Integrating fish into seasonally flooded rice fields: on-farm trials in Assam, India

In the State of Assam, floodplains cover 2.6 million ha of area that is traditionally rice growing. The ecosystem in the rice-growing areas has undergone major changes as a result of various developmental activities and adoption of modern farming technology. Rice fields were once the major source of fish for the rural farmers. There has been a sharp decline in fish population in rice field leading to a chronic shortage of fish in the State and a deterioration of the rice ecosystem. This paper describes two on-farm experiments for integrating rice cultivation and fish production with the intent of contributing to the understanding of how raising fish can improve rice yields, riceecosystems and farm incomes.

Integrated resources management, integrated agriculture-aquaculture and the African farmer

Despite the expenditure of huge amounts of money and human effort, the Green Revolution has largely failed to benefit the vast majority of the rural poor in Africa: those smallholding farmers who sell little, if any, of what they grow and rely almost entirely upon natural soil fertility, rainfall and traditional broodstock and seed varieties. New approaches on food production and income generation in the rural areas must be found if this sector of agricultural community is to be assisted. Integrated resources management (IRM) in general, and integrated agriculture-aquaculture (IAA) in particular, may offer some solutions in cases where the classical methods of improving farm output have failed and/or been unsustainable.

Seasonality, labor and integration of aquaculture into southern African smallhold farming systems

Fish production on Malawian smallholdings is generally limited by the quantity and quality of inputs to the pond (Brummett and Noble 1995). The timing of labor availability and other farm activities limit the amount farmers put into their ponds resulting in lower growth rates and yields. There is potential for improving production and yields through modifications of production schedules to accommodate other farming activities. Limited material and labor inputs among farming system enterprises can be better allocated by considering seasonal availability of inputs and adapting the pond and fish farming technology to the farming system. This case from Malawi demonstrates that aquaculture technology that neglects the annual cycle of events and constraints on the farm will not be easily integrated into the farming system. Focusing on technology that maximizes fish production rather than facilitation of adoption and integration has been a feature of the majority of African smallholder agriculture/aquaculture projects. Farming Systems Research (FSR) must identify niches and opportunities for system improvement for it to be worth supporting as a development intervention.

River-based artificial propagation of the African catfish Clarias gariepinus: an option for the small fish farmer

A cheap method of propagating the African catfish, Clarias gariepinus, by incubating the fertilized eggs in a cage placed directly in a flowing river is described. Hatching ranged between 39 and 70%. This is not significantly different from the commonly used water recirculating flow through system. The economic advantages of the river hatching method are discussed with special emphasis on the rural fish farmers.

Small scale rural aquaculture in Assam, India: a case study

The state of Assam in northeastern India has an excellent sub-tropical climate for the development of fresh water fish culture in a variety of aquatic bodies. Aquaculture not only plays an important role in nutrition but also in the rural economy of the State. A pilot project conducted with a group of resource poor tribal farmers revealed that a production of about 1 800 kg/ha/yr could be achieved from small seasonal homestead ponds through integrated use of locally available biological resources. This implies an excellent opportunity for improving the rural economy through the development of small-scale fish culture enterprises. In this project, a greater emphasis was placed on improving the knowledge and skills of the farmers and their farming practices so that in the future they would be in a position to expand their activities with financial assistance made available locally. Aquaculture being a new activity in the area, this pilot project was only a start in acquainting the farmers with the practice and potential of aquaculture.

Integrated farming: a new approach in the Basse Casamance, Senegal

Environmental changes due to 2 decades of drought have modified the ecosystem of the Basse Casamance, Senegal thus forcing farmers to change their practices. They have built fish ponds and diversified into crops such as peanut, millet, sorghum, cassava and vegetables. The ponds have 2 purposes - to protect ricefields against inflow of brackishwater and to raise fish. The fish complements rice, which is the main diet, adding animal protein and serving as a source of income. Although this integrated farming system is little developed at present, it has good potential to rationalize use of the resources available to farmers and to promote interactions between farm enterprises.

Pawpaw seed as fertility control agent on male Nile tilapia

To find out if pawpaw (Carica papaya) seeds can induce sterility in male Nile tilapia (Oreochromis niloticus) and to determine if sterility so induced is reversible or otherwise, mature male tilapia of mean weight 40 g were treated for 30 days with a low dose (4.9 g/kg/day) and a high dose (9.8 g/kg/day) of ground pawpaw seeds incorporated into their feed. Fish of similar sizes in the control experiment were fed with feed that did not contain pawpaw seed. The pawpaw seeds induced permanent sterility in the fish that received the high dose, while sterility in the low dose treatment was reversible. Fish in the control experiment spawned two weeks into the experiment and again in the fifth week. Fish in the low dose treatment spawned three weeks after the treatment had been discontinued. Histological sections of the testes showed that pawpaw seeds produced swollen nuclei in the low dose treatment and disintegrated cells in the high dose treatment. The study showed that pawpaw seeds, which are easy to obtain, can be incorporated into fish feeds and used by farmers to control prolific breeding of Nile tilapia.

Management of mangrove areas in Calauag Bay, Quezon Province, Philippines

The findings are presented of a study conducted in Calauag Bay, Quezon Province, Philippines in order to estimate resource rent of mangrove areas converted to fishpond production. The rents were calculated based on the technology practised by the farmers and the prices of inputs and outputs that prevailed during the study period. The major causes of mangrove depletion are cutting of mangroves for fuelwood and charcoal and clearing for fishpond development. It was concluded that there is justification for the government to increase the feed which could be used to rehabilitate the inland-coastal fisheries to improve productivity and ensure sustainability of the ecosystem for future generations.

Aquaculture genetics research and issues in INGA member countries/institutions

The information presented here is extracted from the presentations and discussions at the Sixth Steering Committee Meeting of the International Network on Genetics in Aquaculture (INGA) held in Hanoi, Vietnam on 8-10 May 2001. The main topics discussed were: review of genetics research progress and planned activities in member countries and Associate Member institutions; genetics improvement technologies; strategies and action plans for distribution of improved fish breeds to small-scale farmers; ecological risk assessment for genetically improved fish breeds; methods for monitoring the uptake of improved strains and impact assessment; and network activities and collaborations.

Markets, marketing and production issues for aquaculture in East Africa: the case of Uganda

Aquaculture is currently responsible for an insignificant proportion of total fish production in Uganda. However, given the increasing demand for fresh fish in urban and peri-urban araes, and threats to the supply of fish from natural catch fisheries, the potential exists for a strong market in aquaculture. Small-scale fish farmers located relatively close to markets or all-season roads, and who can supply consistent and high quality produce, will have the widest range of marketing opportunities, and will likely be within the area of operation of potential traders and intermediaries that deliver fish to markets. Fish farmers that are not close to roads, or produce unreliable quantities and variable quality products may face high transaction costs of marketing their product, and decreasing net returns to production. The authors found that significant on-farm labor, and access to input markets are important factors leading to positive net returns to fish production. Areas with high population density and relatively low wages will be well suited to labor intensive aquaculture. The authors concluded that aquaculture development has good potential in certain areas of Uganda and should therefore be pursued as a potential development pathway. However, policy makers should consider the importance of the price of fresh fish relative to the cost of labor, as well as other factors including the importance of smallholder credit and access to extension services, when directing investments in aquaculture technology.

Twenty sea cucumbers from seas around India

Twenty species of sea cucumbers from India are described briefly, with photographs which will enable research workers and farmers to identify them.

Genetic diversity and selective breeding of red common carps in China

China has a very rich genetic diversity in common carp (Cyprinus carpio) and the red common carp plays an important role in Chinese aquaculture and genetic studies. Selective breeding, particularly crossbreeding has been applied successfully to red common carps in China, and the products of these efforts have been in commercial use since the 1970s. However, knowledge of the quantitative and molecular genetics of these carps is limited. Studies were therefore undertaken to: (1) understand the genetic diversity and genetic relationship of red common carps in China; (2) understand the inheritance of color phenotype of Oujiang color carp; (3) select stable Oujiang color carp with fast growth rate and ornamental Oujiang color carp comparable with the Koi common carp from Japan; (4) study the culture performance and culture systems suitable for the Oujiang color carp in cages and paddies; (5) extend better quality fish and appropriate culture systems for small scale fish farmers in poor areas.