Efficiency Comparison between Conventional and Vented Trap in Ghost Fishing Experiment, Si Racha Bay, Gulf of Thailand

raps are an effective and economically important multi-species fishing gear used widely for harvesting crustaceans and finfish around the world. The collapsible trap targeting blue swimming crab (Portunus pelagicus) has recently becomes a major type of fishing gear and operated over year in the Gulf of Thailand. Small scale fishers operate their traps inshore with the numbers of 200-300 traps/boat while commercial scale fishers operate further (offshore) with the numbers of 2,000-5,000 traps onboard. Both fishing types have possibilities become lost or derelict as a result of several processes. Lost traps are widely thought to result in mortality because of “ghost fishing” a term used to describe the process by which derelict fishing gear continues to trap organisms and induce mortality in an uncontrolled manner (Matsuoka et al. 2005). The phenomenon of ghost fishing is a concern to fisheries managers and the fishing community interested in long term sustainability of the trap fishery. The ghost fishing effects on the blue swimming crab and other animals from the trap fishing in Thailand have been very poor evaluated and reported. Accordingly, the objectives of this study were to examine the ghost fishing characteristics of the conventional trap used by small scale fishers compared to the vented trap. Specifically, the rates of entrance and mortality of the target species and the by–catch species were assessed and compared between both trap types