Migrations of the loggerhead sea turtle, Caretta caretta, into the Adriatic Sea

Data on migrations of sea turtles in the Adriatic Sea are extremely rare. In the first 10 years of the implementation of tagging programs in the Mediterranean basin (1981/82-1992), 13 tagged loggerheads were recaptured in the Adriatic Sea, only 4 being reported from Croatian waters. Our results are based upon recoveries of tagged loggerheads along the Croatian coast of the Adriatic Sea, in the period between 1993 and 1996. Eleven tagged loggerhead females were recovered, all being tagged in Greece by STPS. The longest migration of about 1, 200 km was recorded for specimens recovered in the Northern Adriatic. The shortest period between last record on the nesting beach and recovery in Croatia was 43 days. The specimen migrated at least 750 km, which indicates an average speed of about 17.5 km/day. The 11 in-transit recoveries of migrants in Croatia show that part of the Greek loggerhead nesting population migrates into the Adriatic Sea. Although migratory behavior is unknown, it is probable that the Adriatic represents their feeding and developmental area. It seems that the migratory pathway of loggerheads into the Adriatic leads along the eastern Adriatic coast, toward the north. This route overlaps with the current that enters the Adriatic along the eastern coast and surely have an influence on the direction of loggerhead migration.