Assessments made of shrimp catches in Kuwait and available stocks indicate that finfish eat a large majority of theshrimp available. Management measures to be taken in order to reduce this predation problem are considered.
The production characteristics of shrimp farming in Bangladesh are reported based on a panel of farms for the period 1998 to 2002. The data allow for a profit decomposition based on the Törnqvist index, where differences in relative profits can be explained by differences in productivity, prices, and pond size. The indices indicate that pond size is the most important factor in determining profitability and that the largest farms are the most profitable. However, productivity measured as profit per hectare is only weakly positively correlated with pond size.
Seafarming to produce human food has recently intensified, particularly in the Asia-Pacific region. Disastrous impacts of harmful phytoplankton blooms, however, have been experenced during the past 20 years. In extreme cases, these render shellfish and finfish toxic or cause massive fish and shrimp kills. Problems from marine algae in the region include paralytic shellfish poisoning, diarrhetic shellfish poisoning, ciguatera, tetrodotoxin poisoning, fish kills and tainting of fish and shellfish.
Mortality rates of reef fishes are typically very high in the first few weeks after settlement. Capture and release of reef fish before or shortly after settlement may provide an opportunity to increase survival. Increasing survival at this stage could be a sustainable way of increasing fisheries resources. visual censuses of juvenile grunts (Haemulidae) during settlement pulses from January to March 2001 and July to September 2001 in Tortola, British Virgin Ilands were used to estimate local post-settlement mortality rates on a back-reef, seagrass/sand halo area.
Length frequency data of six sciaenids (Johnius macrorhynus, J. vogleri, Otolithes cuvieri, J. sina, Pennahia macrophthalamus, J. dussumieri) were collected from shrimp trawlers at New Ferry Wharf and Sasson Docks landing centers off Greater Mumbai (India). Growth parameters of these species were analyzed via modal progression analysis using Bhattacharya's method. Natural mortality (m) was estimated using Cushing's formula. Comparison of growth parameters was done using the 0' index.
Spawning success in relation to the size of spawner, clumping of eggs, percentage of spawning and frequency of spawning was studied in Penaeus monodon collected off Tamil Nadu, India. The results indicated positive correlation between the size of spawner and the fecundity and hatching percentage, but not the start of hatching. Hatching characteristics were influenced by clumping of eggs or abortive spawning; the greater the clumping, the longer the time taken for hatching, resulting in a lower hatching percentage.
Marine crabs belonging to the family Portunidae form bycatch of shrimp trawlers in India. They are sold at low prices and consumers discard eggs and consume the meat. The paper details the nutritional value of eggs of Portunus pelagicus.
At least 60 species of crustaceans are farmed experimentally or commercially, mostly in the tropics and subtropics where species maturation times are shorter than in temperate climates. Over 50 species are kept by aquarists, and several, especially Artemia spp., are widely used as live foods for rearing fish and aquatic invertebrates. However, there has been far less application of genetics in crustacean farming than in finfish and mollusc farming, and very few crustaceans can be regarded as domesticated.
The effect of aquaculture, especially shrimp farming, on agriculture has caused heated debate among aquaculturists, agriculturists, and non-governmental organizations. As data on the negative impact of shrimp farming on adjacent rice fields are not available, a study was undertaken in rice fields skirting three shrimp farms: a semi-intensive farm; an extensive farm; and a semi-intensive farm with a buffer zone.
This paper introduces the characteristics of the Delta and outlines the pressures that are impinging on the sustainability of the Delta's wetlands. Although these pressures are non-linear and interacting, three are considered prominent. These pressures stem largely from rice production and the associated large scale water control infrastructures, shrimp aquaculture, and the inadequacy of the current institutional arrangements. Responses to these pressures are discussed noting the diverse interventions made in the past and the present.