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.

Small-scale fishery of Pichavaram mangrove swamp, Southeast India

A description of the small-scale fishery of Pichavaram mangrove, southeast India is given, with emphasis on catch composition, catch per effort and deployment of various gear types.

Community management of coastal resources, southern Thailand

The involvement of communities with the assistance and support of government and non government organizations on the management of the coastal resources in Southern Thailand are discussed. The 3 most important resources, mangrove, seagrass and coral, create a complex coastal ecology. Several man-made activities causing the deterioration of this resources are also presented.

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.

Problems for the conservation of freshwater fish genetic resources in India and some possible solutions

Many interconnected problems involved for the conservation of freshwater fish genetic resources of India are enumerated. Some possible solutions to the problems are also discussed.

A comparison of monofilament gillnet and small hook longline selectivity in a multispecies artisanal fishery in the Algarve, southern Portugal

As part of the ongoing studies concerned with the small-scale fisheries of the South of Portugal, experimental fishing was carried out with monofilament gillnets and small hook longlines within the same area. Sixty-two species were caught, of which 20 were common to both gears. Pronounced differences in terms of the relative importance of different species in the catches were observed. Size selection patterns also differed, with highly overlapped hook catch distributions and few species showing evidence for size selectivity. In contrast, strong selectivity was characteristic of species which tend to be wedged in gillnets. Whereas smaller stretched mesh sizes (particularly 40 and 50 mm) caught significant numbers of illegal sized fish, this was mininmal in the longlines. Some implications for management are discussed.

Conservation of the Nilgiri rainbow trout in India

Rainbow trout is one of the important exotic species that is well established in the upland waters of India. This paper presents the historical background of its introduction and the present status of the fish in the streams of he Nilgiri peninsula of India. The rainbow trout inhabits natural reservoirs and streams of the region as a self-recruiting population. The growth rate is reported to be relatively low and conflicting views about its taxonomic status have been reported. Successful crossbreeding of the Nilgiri rainbow trout with trout stocks from the Indian State of Himachal Pradesh has indicated the scope for utilizing cryopreserved milt as a mode of introducing new genetic material into the Nilgiri rainbow trout population. This paper outlines the requirement of ecological and genetic data to develop a strategy for management and reintroduction fresh stocks.

Length-weight relationship of marine fishes from southern Brazil

The relationship between length (L) and weight (W) was estimated for 80 species belonging to 50 families of marine fishes from the shelf and upper slope of southern Brazil (lat. 28°S - 34°S). Sample sizes (n) for different species ranged from 11 to 14 741 specimens collected from commercial landings and research surveys. The fit of the equations (W=aLb) with a and b parameters estimated from regular and functional regression (of log-transformed weight and length data) as well as from a non-linear iterative process using the quasi-Newton algorithm were compared. The non-linear method gave the most accurate estimates in terms of residual sum of squares. Differences were less than 2.3% for n>500 compared with predictive regressions and 1.5% compared with functional regressions. No difference was observed between both predictive and functional regressions. Determination coefficients (r2) increased with sample size, and the highest r2 were obtained for 50

Hatchery and culture technology for the sea cucumber Holothuria scabra Jaeger, in India

The seed of the sea cucumber Holothuria scabra jaeger is being produced at the Central Marine Fisheries Research Institute in India. This article describes the techniques being used in the production of seed and the experiments being carried out for the rearing of juveniles. Trials to grow juveniles in hatcheries on prawn farms have shown spectabular results that are both cost efficient and environmentally friendly.

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.

Freshwater pearl culture in India

Freshwater pearl culture is growing as a source of employment and income in many Southeast Asian countries. Bangladesh, Thailand, the Philippines and Vietnam have initiated freshwater pearl culture projects in recent years. In India, the Central Institute of Freshwater Aquaculture is carrying out research on identification of suitable local pearl mussel species (Genera Lamellidens)defining appropriate surgical implantation procedures, developing post-operative care procedures and captive pond culture of mussels.

Economic incentives for water resource management in the Pak Phanang river basin of southern Thailand

The study examines the existing water allocation methods and other policies that provide constraints or incentives for the most efficient use of water resources. Given the production condition of the local people, and the technical and physical attributes of water resources, the principal hypothesis of this study is that the benefits obtained from fresh water resources in the study area can be improved through better resource management.

Population parameters of Pennahia anea and Nibea maculata in the Palk Bay/Gulf of Mannar area, India

The population parameters of the two most abundant sciaenids comprising the trawl catch in the Palk Bay/Gulf of Mannar area are presented. The following parameters were estimated: 233 mm (L sub( infinity )), 1.26 yr super(1) (K), -0.08 yr (t sub(0)), 4.24 yr super(1) (Z) and 2.24 yr super(1)(M) for Pennahia anear, 284 mm (L sub( infinity )), 1.08 yr super(1) (K), -0.05 yr (t sub(0)), 4.41 yr super(1) (Z) and 1.92 yr super(1) for Nibea maculata. Length at first capture was 97 mm for P. anea and 124 mm for N. maculata. These lengths were noted to be less than the corresponding length at first maturity for both species. The exploitation rates (E) derived indicate that the two species are heavily fished, which may account for the decline in sciaenid catches from 1988 to 1992.

Analysis of RAPD polymorphisms in Rastrelliger kanagurta off India

Analysis of RAPD loci in Indian mackerel (Rastrelliger kanagurta), as generated by the arbitrary primer OPA 07 (GAAACGGGTG), revealed a maximum within-region genetic variability for samples from the east coast of India. Dendograms did not show clear centre-specific clusters. Restricted intermixing among the individuals between the east and west coasts in suggested.

Seaweed industry in India

The seaweed industry in India is mainly a cottage industry and is based only on the natural stock of agar yielding red seaweeds, such as Gelidiella acerosa and Gracilaria eduli and algin yielding brown seaweed species such as Sargassum and Turbinaria. India produces 110-132 t of dry agar annually utilizing about 880-1100 t of dry agarophytes, and 360-540 t of algin from 3600-5400 t of dry alginophytes.