A Review of Biological Studies on Sea Turtles in Japan

Abstract

To clarify the research history of sea turtle biology in Japan, a total of 256 scientific publications are reviewed in relation to the following six categories: taxonomy, distribution, development, genetics, ecology and ethology, and local research activities. The oldest scientific study project was started in 1880 on Chichijima Island of the Ogasawara Islands to conserve the stock of green turtles as a food resource. This study is still continuing and allows us to grasp the fluctuation in numbers of turtles captured. On the other hand, taxonomic study of Japanese sea turtles, which was initiated in 1907 by L. Stejneger, achieved little progress until the 1960-70's when Nishimura clarified the correct species names of Japanese members and their distributions. In the 1980's, many volunteers started research on the loggerhead turtle in its nesting sites at various localities in Japan. With the advance of research activities, ecological information has been accumulated for several nesting beaches and reported mainly in local publications. These publications, mostly written in Japanese and not circulated widely, are difficult to obtain for researchers abroad and usually neglected or unnoticed by them, or in the worst case, even by Japanese researchers. However, some of these studies include important information, as examplified by the data accumulated nearly 50 years for nesting fluctuation on the Ohama and Kamouda Beaches. Therefore, they are actually of great value in considering biology and conservation of sea turtles.