ENVIRONMENTAL IMPACTS OF JUVENILE CRAB FISHING

Impact of the seed fishery on wild stocks

Removal of mud crab seed-stock from the wild can result in recruitment failure for the stock as a whole if fishing pressure is high enough. This appears to have happened in a range of localities in the Philippines. The impact of the seed fishery on the wild stocks will depend on the size of the population, the take of the fishery, food availability and maintenance of the habitat supporting the fishery. In Viet Nam, Lindner (2005) considered “there may be limited scope for further expansion of crab fattening due to its reliance on wild crab stocks that are claimed to be fully exploited”.

It has been shown that mud crab recruitment can be continuous throughout the year in some fisheries which may explain why such fisheries can be quite resistant to heavy fishing pressure (Le Vay, Ngoc Ut and Jones, 2001). However, unlike the fishery examined by Le Vay, Ngoc Ut and Jones (2001), few mud crab fisheries have been well researched, so that changes in baseline variation in crab abundance can be monitored to assess the effectiveness of either management provisions, habitat change or fishing pressure.

 

Impact of seed collection on the ecosystem

Apart from over collection of mud crab seed-stock resulting in decreased crab populations in some areas, little appears to have been researched regarding the impact on ecosystems of this practise.