Species Diversity and Distribution of Gammarid Amphipod in Pristine and Aquacultural Areas of Outer Songkhla Lake

Abstract

Outer Songkhla Lake is an important fishing ground of Songkhla Province. The area is of importance both for fisheries and aquaculture (especially fish cage farming); the latter helps relieve the pressure on fisheries but nevertheless causes nutrient pollution. Since gammarid amphipod is a major
benthos in Songkhla Lake and is commonly used as a bioindicator for detecting marine pollution, the amphipod diversity and distribution in both pristine and aquacutural areas of the Outer Songkhla Lake were investigated during November-December, 2014. A total of 12 species from 8 families was found. The dominant species, occurring in both areas and both months were Grandidierella gilesi Chilton, 1921, Eriopisella sp.1, Victoriopisa chilkensis (Chilton, 1921) and Melita latiflagella Ren & Andress, 2012. The amphipod densities ranged between 0-1,200 individuals/m2. Amphipod species diversity and density in pristine areas were higher than those in the aquacultural area. However, the amphipods distribution and other environmental factors of both areas were not significantly different (p>0.05).