Location and Number of Individuals of Indo-Pacific Bottlenose Dolphins {Tursiops aduncus) in Kagoshima Bay

The dolphins in Kagoshima Bay were studied to clarify their population size and distribution. In order to determine their distribution, 9 surveys were conducted in the whole bay from 1999 to 2000, and ll surveys in the innermost area from 2000 to 2001. To identify their species, 39 surveys were conducted from 1999 to 2001. Tursiops dolphins were observed 48 times, and in 47 observations they were identified as Indo-Pacific bottlenose dolphin (T. aduncus) from their external morphology. These dolphins were observed near the shore of the innermost area of the bay. The mean school size was 30.74 (ｱ13.90 SD) individuals. There were 50 individuals in 1999, 40 individuals in 2000, and 50 individuals in 2001. Twenty five individuals were identified by photography and 12 identified individuals of them were observed throughout 3 years. The slight change in the number of identified dolphins indicated the possibility of their residency inside the bay