SATELLITE TRACKING OF COASTAL BRYDE’S WHALES BALAENOPTERA EDENI ALONG THE SOUTHWEST COAST OF JAPAN

Abstract

To examine the movements of Bryde's whales, Balaenoptera edeni, in coastal waters off Japan, satellite tagging was conducted off Kochi, the southwest coast of Tosa Bay from 2004 to 2008, and off Nomaike, on the southwest coast of the Satsuma Peninsula in 2005. Using an air gun, an Argos satellite tag was attached on the animal from a whale watching boat. A total of 20 shots were taken at 17 individuals, and tags were successfully attached to 11. Geographical locations from the Argos Satellite were obtained from seven animals. The maximum tracking period was 30 days in Tosa Bay, and 40 days off Nomaike. Most individuals stayed in the same waters for at least several weeks in the summer season (July to August). However, one individual moved from Tosa Bay to the Kii Peninsula, and one from Nomaike to the Goto Islands in the East China Sea. No animals moved to the offshore waters across the Kuroshio Current. This result supports the current classification of the stock of coastal Bryde's whales (the East China Sea Stock). Further technical improvements are necessary to increase the tagging success rates and extend the tracking period to investigate movements and distributional ranges of Bryde's whales in the coastal waters off Japan.