Species composition of aquatic fauna harvested by small-scale fishing gears in Amphoe Sikao, Changwat Trang

Species composition of aquatic fauna captured by six types of small-scale fishing gear, in Amphoe Sikao, Changwat Trang were investigated during September 1994 to March 1995. Harvest rates were quantified according to the number of animals and the total length and weight of each species per catch. Twenty-one species were caught by trammel nets including shrimp 28.45 percent, fish 49.23 percent crab 3.78 percent, squid 9.8 percent and mantis shrimp 3.8 percent. Crab gill nets were able to catch 11 species including crab 75.58 percent, fish 18.59 percent, squid 1.63 percent and mantis shrimp 4.2 percent. While 7 species were harvested by the whiting gill nets, there were whiting fish 79.83 percent, other fish 13.87 percent and crab 6.3 percent. Mullet gill nets caught 7 species including 60.88 percent and 39.12 percent of mullets and other fish respectively. Squid traps were able to capture a total number of 7 species of squid, fish and crab at 77.8 percent, 14.82 percent and 7.38 percent respectively. The handlines harvested 10 species which were included sanpper 33.33 percent, grouper 10.11 percent, baracudas 14.9 percent and other fish 41.66 percent. All types of small-scale fishing gear except the trammel net were able to capture the target species. For some species and gear types, there were significant differences in total length and weight of catch between the dry and the wet seasons. These differences are as follow: total length (centimetre) [16.58, 15.19] and weight (gram) [33.4, 29.1] of shrimp, [13.7, 11.89] and [208.1, 198.75] of aquid, [13.72, 13.5] and [46.96, 46.54] of fish caught by trammel nets, total length [11.24, 12.03] and weight [38.9, 40.9] of fish and crab [12.71, 14.10] and [111.4, 121.0] caught by whiting gill nets, total length and weight of crab [18.25, 16.3 and 150.5, 138.7] and net weight (kilogram) of fish caught by squid traps. Though seasonal changes have an affect on size and weight of species caught, but they do not affect the species composition of animals captured by each small-scale fishing gear.