Settlement ponds are used to remove particulate and dissolved nutrients in Australian land-based aquaculture wastewater. At best, marine and brackish water settlement ponds reduce total suspended solids by 60%, but their efficiency is inconsistent. Functional improvements to nutrient removal systems are essential to provide uniform and predictable treatment of flow-through aquaculture wastewater. Furthermore, environmental regulation of discharge from intensive systems in Australia is increasing, providing the impetus to upgrade rudimentary single-step settlement pond systems.
Millions of people around the world depend on shrimp aquaculture for their livelihoods. Yet, the phenomenal growth of shrimp farming has often given rise to considerable environmental and social damage. This article examines the impacts of commercial, export-oriented shrimp aquaculture on local livelihood vulnerability by comparing the exposure, sensitivity, and adaptive capacity of shrimp farm employees with non-farm employees in rural Mozambique.
A preliminary mass-balance trophic model was constructed for the coastal fisheries ecosystem of the West Coast of Peninsular Malaysia (0 - 120 m depth). The ecosystem was partitioned into 15 trophic groups, and biomasses for selected groups were obtained from research (trawl) surveys conducted in the area in 1987 and 1991. Trophic interactions of the groups are presented. The network analysis indicates that fishing fleets for demersal fishes and prawns have a major direct or indirect impact on most high-trophic level groups in the ecosystem.
Research trawl surveys have been conducted in four areas of Malaysian waters (west and east coast of Peninsular Malaysia, and waters off the coast of Sarawak and off the west coast of Sabah) since 1970. Selected surveys (1972 - 98) were used to examine the status of demersal fishery resources in each area, focusing on catch rate and biomass trends, population parameters and the exploitation rates of dominant species.
Relative biomass per recruit of adult (i.e. sexually mature) fin to shellfish is shown to help in identifying levels of fishing mortality likely to lead to recruitment overfishing. This is illustrated with data from a Malaysian penaeid shrimp fishery.
Thailand is currently one of the ten largest fishing nations in the world. In 1996, fish production reached 3.7 million t with 90% of the production coming from the marine fisheries sector and 10% from inland fisheries. Thai fishing operates in four fishing grounds namely, the Gulf of Thailand, the Andaman Sea, the South China Sea and the Bay of Bengal. However with the establishment of the Exclusive Economic Zone (EEZ) in 1977, Thailand lost over 300 000 km2 of traditional fishing grounds.
Bangladesh has an exclusive economic zone (EEZ) of 164 000 km2 and a continental shelf area of 66 440 km2. Artisanal (small scale) fisheries extend from the coast to 40 m while industrial (commercial scale) fisheries operate beyond 40 m depth. The coastal fisheries of Bangladesh exploit a complex multi-species resource. There are 18 demersal and pelagic species, seven species of larger pelagic and 10 shrimp species that are commercially important among the fishes exploited.
Fish has been a staple food for over a billion people. Its demand is increasing due to growing population and awareness about health benefits of aquatic animal food. Disappointingly, wild catch worldwide is on the decline and aquaculture is emerging as the only solution. It grew at 9%/yr in the last 10 years becoming the fastest growing food production sector. At present, aquaculture produces only about 45 million t per year but it needs to be doubled by 2030 to meet its growing demand. Asia produces over 85% of the global farmed fish - mostly by small-scale farmers.
The shrimp industry in Bangladesh is the major fisheries foreign exchange earner. The various processing industries consist of freezing plants, smoking/drying factories and meal factories. Details are given of the freezing plants ofBangladesh, quality control laboratories and smoking factories, and also the various shrimp products produced. Suggestions are made for improved production.
An account is given of shrimp farming and its benefits to India, discussing effective land use, the use of naturalshrimp seed resources, foreign exchange and employment in rural areas.