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.

Pig-duck-fish-azolla integration in La Union, Philippines

Three studies on pig-duck-fish-azolla integration were conducted simultaneously in La Union, Philippines. Growth performance of pigs and ducks as affected by different levels of azolla meal in their feed, and that of tilapia (Oreochromis niloticus) under varying stocking rates are presented and discussed.

Integration of freshwater prawn culture with rice farming in Kuttanad, India

The integration of paddy cultivation with prawn/fish culture can become a viable alternative to effectively utilize the vast area of derelict polders (embanked coastal flood plains) in Kuttanad, India. Nearly 55 000 ha of wetlands in Kuttanad are available for paddy cultivation year-round. Around 5 000 ha of the polders are utilized for Macrobrachium rosenbergii culture as a follow-up crop. Of the total area, about 250 ha of fallow polders are utilized for monoculture of M. rosenbergii from March to October, while in 4 750 ha polyculture with Indian and exotic carps is practiced from November to June. Stocking density is 15 000 to 60 000/ha for monoculture of M. rosenbergii, while in polyculture with carps, it is 5 000 to 20 000/ha of prawn and 5 000 to 10 000/ha of fish. Production from monoculture varies from 95 to 1 297 kg/ha whereas production from polyculture systems it is 70 to 500 kg/ha of prawn and 200 - 1 200 kg/ha of fish. Profits range from Rs. 5 000 to 20 000/ha. An evaluation is made of how the present polders of Kuttanad are best utilized for culture of M. rosenbergii following different systems of integrated farming and how the integration is useful in the aquaculture sustainability of Kuttanad, a tropical wetland ecosystem.

Integration of crustacean aquaculture with coastal rice farming in Vietnam

Some examples are given of integration of crustacean aquaculture into coastal rice farming in Vietnam. Freshwater prawn (Macrobrachium rosenbergii ) and marine shrimp culture integrated with coastal rice farming and crab (Scylla serrata ) culture in backyard ponds and ricefields are described.

Integration of aquaculture and agriculture: a route to sustainable farming systems

The integration of agriculture and aquaculture as a means of intensifying resource use and improving the productivity of many current farming practices in Southeast Asian and African countries is discussed. A brief account is given of work undertaken by ICLARM in Malawi and India regarding the improved use of marginal lands to integrate crops, vegetables, trees, livestock and fish, outlining also the various problems involved in the extension of such integrated fish farming systems.

Length-weight relationship of some deep-sea fish inhabiting the continental slope beyond 250m depth along the west coast of India

The length–weight relationships of 22 species of deep-sea fishes inhabiting the continental slopes beyond 250 m depth along the West Coast of India are presented. The parameters a and b of the equation W=a Lb were estimated. The fish samples were collected from trawl surveys during 1999 to 2001 on board the FORV Sagar Sampada at a depth range of 250 to 600 m in the area between 7°N and 20°N latitude. The value of b ranged from 1.94 to 3.36.

Fishery-independent Bottom Trawl Surveys for Deep-water Fishes and Invertebrates of the U.S. Gulf of Mexico, 2002–08

From 2002 through 2008, the Mississippi Laboratories of the NMFS Southeast Fisheries Science Center, NOAA, conducted fishery-independent bottom trawl surveys for continental shelf and outer-continental shelf deep-water fishes and invertebrates of the U.S. Gulf of Mexico (50–500 m bottom depths). Five-hundred and ninety species were captured at 797 bottom trawl locations. Standardized survey gear and randomly selected survey sites have facilitated development of a fishery-independent time series that characterizes species diversity, distributions, and catch per unit effort. The fishery-independent surveys provide synoptic descriptions of deep-water fauna potentially impacted by various anthropogenic factors.

Agassiz, Garman, Albatross, and the Collection of Deep-sea Fishes

The first of Alexander Agassiz’ voyages on the U.S. Fish Commission steamer Albatross in 1891 yielded significant scientific results. This paper reviews the background of the voyage, including the career path that led Agassiz to the back deck of the Albatross. We also give a brief account of the life and work of Samuel Garman. Garman wrote up the ichthyological material from this Albatross voyage in a magnificent book on deep-sea fishes published in 1899. This book was exceptional in its coverage, anatomical detail, and recognition of phylogenetically important morphology.

Remote Camera and Trapping Survey of the Deep-water Shrimps Heterocarpus laevigatus and H. ensifer and the Geryonid Crab Chaceon granulatus in Palau

Time-lapse remote photo-sequences at 73-700 m depth off Palau, Western Caroline Islands, show that the caridean shrimp Heterocarpus laevigatus tends to be a solitary animal, occurring below ~350 m, that gradually accumulates around bait sites over a prolonged period. A smaller speies, H. ensifer, tends to move erratically in swarms, appearing in large numbers in the upper part of its range (<250 m) during the evening crepuscular period and disappearing at dawn. Trapping and photsequence data indicate the depth range of H. ensifer (during daylight) is ~250-550 M, while H. laevigatus ranges from 350 m to at least 800 m, along with the geryonid crab Chaceon granulatus. Combined trapping for Heterocarpus laevigatus and Chaceon granulatus, using a three-chamber box-trap and extended soak times (48-72 hr), may be an appropriate technique for small-scale deep-water fisheries along forereef slopes of Indo-Pacific archipelagoes.