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 mass-balance steady-state trophic model of the coastal fisheries ecosystem off the West Coasts of Sabah and Sarawak, Malaysia (10 - 60 m depth) was constructed using the Ecopath software. The ecosystem models were partitioned into 29 ecological/trophic groups. The input values (e.g. biomasses) for selected groups were obtained from the research (trawl) surveys conducted in the area in 1972. The estimated mean trophic level of the fisheries catch for both models is about 3.3.
Due to inadequate technical knowledge and training in advanced methods of gradually growing shrimp culture, framers are not getting expected yield. From the very beginning of the CSISA-BD project, WoldFish Center has taken initiative to introduce advanced methods of shrimp culture in south-west of Bangladesh. To do this, the shortage of skilled trainers and training materials, has, particularly, been realized.
The present study examined the variation in survival, proportion of male morphotypes, female and male proportion, female reproductive status and tag losses in nine crosses from a complete (3 × 3) diallel mating of three populations of Macrobrachium rosenbergii in India. The populations originated from Gujarat (north-west), Kerala (south-west) and Odisha (east), representing different agro-ecological regions in India. Progeny from 60 families (4773 juveniles) were individually tagged and reared for 16–17 weeks in earthen ponds. Binary logistic regression was used to analyse the data.
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.
The fishing industry in the Philippines was tantamount to a marine capture fishery in the 1950s to 1960s. Aquaculture and inland fishery production were not significant. Only during the 1970s did aquaculture and inland capture fisheries contribute significantly to fish production. From 250 000 t fish production in 1951, this increased substantially to 1.6 million t in the 1990s. An average 4.3% was contributed by fisheries to the gross domestic product from 1988 - 98. Fisheries export earnings reached P12 billion in the 1990s.
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.
An account is given of the shrimp fisheries in Bangladesh during the period of 1972 to 1983.