Post-nesting migration of Japanese loggerhead turtle, Caretta caretta

Abstract

From 1991 through 1995, 2219 nesting loggerhead turtle (Caretta caretta) were marked with plastic and metal tags and were released on 16 nesting beaches between the Ryukyu Archipelago and Shizuoka of Japan. Of them, 55 turtles were recovered until August of 1995, except for the individuals that remigrated to the released beaches. Thirty-four turtles (62%) were found from the coastal waters of Japan and 18 turtles (33%) were obtained from the East China Sea. The remaining two and one turtles were found from the Philippine and the Vietnamese coastal waters, respectively. They are the first records for the loggerhead turtle to be distributed in these areas. Seasons that turtles were recaptured were different between the coastal waters of Japan and the East and South China Sea. In the coastal waters of Japan, a few cases of recapture were reported during the winter. However, in the East and South China Sea, turtles were found almost throughout the year. Therefore, females that nested on the Japanese coast from the late May to the early August are considered to migrate to a wide area of the eastern Pacific, mostly to the East China Sea, after staying in the coastal waters of Japan until about October of the same year. Many of the recapture records were obtained by trawling vessels in the East China Sea and by set nets operating in the Japanese coastal waters. We discussed on their conservation.