The longer period of fishermen work hour defined the available period that dolphin were found in the study area (Figure 50). The results show that dolphin were found frequently in the early morning during 8.00-9.00 with the limition of weather condition that the wind and wave were strong in the afternoon while the fishermen found the dolphin on 18.00-21.00 in the evening also (Figure 50). It is possible that 18.00-21.00 period might be the appropriate