The study was carried out on a weekly basis between June-August 2011. The sampling sites
were at Ban Tah-songkhon (S1), Ban Din-dum (S2) and Ban Bung-kla (S3) (Figure 1). Fish
specimens were taken by local fishermen from each site with gillnets of mesh sizes 35, 45 and 55
mm, which are often used in this area. The fishermen were explained about the purpose of the study
and were free to decide when to fish on each appointed night. The fishing gear was set during 3-6
p.m. and the fishermen came back the next day at 5-7 a.m. to their fishing gear to take the fish
sample from each set of gillnets. Fish samples were taxonomically classified and identified [5-6] into
species. The total length was measured to the nearest centimetre and body weight taken to the
nearest gramme.