Kan suksa phon kan chap sat nam lae khanat ta uan thi mosom doi chai wela lak uan thi tang kan.
1989
Wannakiat Thubthimsang
Study on catch composition and optimum mesh size by different towing time were conducted from April 1986 to April 1988 in the eastern part of the Gulf of Thailand. Experimental mesh sizes of the cod end were 30, 40 and 60 mm. and cover net mesh size was 20 mm. Each net was towed for 1, 2 and 4 hours per haul. The proportion by weight of economic species of marketable size retained in the cod end became higher as the mesh size increased and became lower as the towing time increased. Both catch rate and percentage retained in the cod end decreased as the mesh size increased for most of marine animals except shrimps, crabs and shells. The optimum mesh size is estimated to range between 30 mm. and 79.7 mm. for the dominant fish species in this region. When mesh size is fixed at 40 mm., 71 % of the fish will be retained in the net for 4 hours of towing time. If the minimum mesh size of the cod end is changed from present, fishermen's income will decrease at first but will turn to increase to reach a level higher than the present level in the near future.
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