How fresh is too fresh?: the live reef food fish trade in eastern Indonesia

Although the live reef food fish trade has become an increasingly "hot" topic in the environmental press in recent months, many of the sources reporting on this practice have tended to focus on issues related to the rampant use of sodium cyanide in the trade, rather than the more pressing matter of the looming potential for overexploitation engendered by this practice. Presented in this article is a brief overview of the live reef food fish trade as it is practiced in eastern Indonesia covering the methods used and economics, geographic extent and numerous deleterious effects of the fishery.

A list of commercial fish species from Santarem, state of Para, Brazil

A list, comprising 129 species in 23 families, is presented of the fish commonly caught in 1992/93 in the commercial fisheries around Santarem, Para State, Brazil. The most important families were the Pimelodidae (22 spp.), Cichildae (20) and Serrasalmidae (15), and six species contribute over 50% of the catch in weight.

Tarpon atlanticus in Colombia: a big fish in trouble

The natural history of Tarpon atlanticus (Valenciennes 1846) is reconstructed based on published information. Tarpon is a remarkable fish because of its peculiar larvae, large adult size, migration patterns and its capability to breathe atmospheric air. Destructive fisheries - some using dynamite - have much reduced the population of tarpon along the Caribbean coast of Colombia, and some catch data are presented which document this.

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.

Fish farming through community partiicipation in Assam

The community tanks and ponds in India are seldom used for fish culture. Fish culture as a community based activity has been shown to be economically viable in some parts of the country. This paper describes the success story of fish farming in a community tank in Assam.

Challenges in sustaining and increasing fish production to combat hunger and poverty in Asia

Fish and fisheries make a major contribution to nutritional security and the fight against hunger and poverty in Asia. An additional 37 million t of food fish will be needed by 2020 to meet the needs of the growing population, changing dietary habits and increasing income levels. Production from capture fisheries has reached a plateau, with most fisheries having reached their maximum sustainable yields or being overexploited. A number of challenges need to be addressed if the present production from capture fisheries is to be sustained and aquaculture production increased to bridge the gap between the supply and the growing demand for fish. This needs the commitment of governments to implement policies that foster growth of fisheries and aquaculture and to allocate adequate human and financial resources to the development of the sector.

Genetic enhancement and conservation of aquatic biodiversity in Africa

There is a pressing need to enhance fish production in Africa through improved farm management and the use of improved fish breeds and/or alien species in aquaculture while at the same time conserve the aquatic genetic diversity. This paper presents the outcome of the Expert Consultation on Biosafety and Environmental Impact of Genetic Enhancement and Introduction of Improved Tilapia Strains/Alien Species in Africa held in Nairobi, Kenya on 20-23 February 2002. The main topics discussed were status of aquaculture in Africa and the role of genetic enhancement; potential benefits and risks involved in introduction of genetically improved strains and/or alien species with specific reference to tilapias; existing policies and legislation for the conservation of biodiversity, their strengths and weaknesses; capacity for undertaking genetic enhancement research and implementation of policies for the conservation of aquatic biodiversity.

Catching and rearing postlarval cleaner shrimp for the aquarium trade: results from a WorldFish Center project in Solomon Islands

Between 1999 and 2003, the WorldFish Center in Solomon Islands conducted research into the feasibility of a new fishery based on the capture and culture of postlarval coral reef fish for the live fish trade. The work was carried out in two phases: a research phase from late 1999 to the end of 2002; and a “finetuning” phase in 2003. Most of the species were of value to the marine aquarium trade, with very few live reef food fish recorded. The most valuable ornamentals were the banded cleaner shrimp, Stenopus species. Cleaner shrimp were harvested using crest nets, the method being modified with the addition of a solid, water-retaining cod-end designed to increase survival at capture. Grow-out techniques were improved by rearing the shrimp separately in jars to prevent aggression. The jars were painted black to protect the shrimp from sunlight. An economic model using experimental catch data and farm gate prices indicates that the fishery based on shrimp, supplemented with small numbers of lobster and fish is economically viable. The next step will be setting up a demonstration farm in a village in the Western Province of Solomon Islands.

A computer software package for assessing and managing risks posed by experiments with genetically modified fish and shellfish

Assessment and management of risk is needed for sustainable use of genetically modified aquatic organisms (aquatic GMOs). A computer software package for safely conducting research with genetically modified fish and shellfish is described. By answering a series of questions about the organism and the accessible aquatic ecosystem, a researcher or oversight authority can either identify specific risks or conclude that there is a specific reason for safety of the experiment. Risk assessment protocols with examples involving transgenic coho salmon, triploid grass carp and hybrid tilapia are described. In case a specific risk is identified, the user is led to consider risk management measures, involving culture methods, facilities design and operations management, to minimize the risk. Key features of the software are its user-friendly organization; easy access to explanatory text, literature citations and glossary; and automated completion of a worksheet. Documented completion of the Performance Standards can facilitate approval of a well designed experiment by oversight authorities.

Fish seed production and marketing in northeast Thailand

In northeast Thailand, fish seed production by private hatcheries is being encouranged by the Department of Fisheries. Dissemination of technical knowledge to hatcheries has considerably improved fish seed availability over the last decade, which has stimulated the adoption of fish culture.

Production-related risk in rice-fish culture: a target MOTAD analysis

The article is a summary of the preliminary results of an AFSSRN-funded study on Risk Programming of Rice-Fish Production Systems in the Philippines conducted early 1993 by the AFSSRN-CLSU team. The results show that rice-fish culture leads to a higher rice production compared to rice monoculture.

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.

A preliminary study on the feasibility of using fenced brushparks for fish production in Lake Chilwa, Malawi

A study to investigate the feasibility of using fenced brushparks for fish ranching in Lake Chilwa was conducted for five months at the Kachulu Harbor. In a water depth of 1.4 m enclosures constructed from bamboo sticks embedded in the sediment and surrounded by a 13 mm seine net, were filled with three different subrates (Typha, bamboo, and Sesbania branches) and a no substrate enclosure served as a control. Netting materials contributed 57 per cent towards the total cost (US$ 0.24-0.30/m2) of brushpark contruction. Fish productivity was highest in the Typha, bamboo and control treatments and lowest in the Sesbania treatments. The decomposition of substrates did not affect water quality. The results indicate that enclosed brushparks may be a feasible technology for enhancing fish yields and providing alternative income sources to fisherfolk in small lakes and water bodies.

Physico-chemical factors and bacteria in fish ponds

Analyses of pond water and mud samples show that nitrifying bacteria (including ammonifying bacteria, nitrite bacteria, nitrobacteria and denitrifying bacteria) are in general closely correlated with various physico-chemical factors, ammonifying bacteria are mainly correlated with dissolved oxygen; denitrifying bacteria are inversely correlated with phosphorus; nitrite bacteria are closely correlated with nitrites, nitrobacteria are inversely correlated with ammoniac nitrogen. The nitrifying bacteria are more closely correlated with heterotrophic bacteria. Nitrobacteria are inversely correlated with anaerobic heterotrophic bacteria. The correlation is quite weak between all the nitrite bacteria which indicates that the nitrite bacteria have a controlling and regulating function in water quality and there is no interdependence as each plays a role of its own. The paper also discusses how the superficial soil (pond mud down to 3.5 cm deep) and different layers of the mud affect the biomass of bacteria. The study shows that the top superficial layer (down to 1.5 cm deep) is the major area for decomposing and converting organic matter.