Differences in size and reproductive output of loggerhead turtles Caretta caretta nesting in the eastern Mediterranean Sea are linked to foraging site

Marine Ecology Progress Series

Aliki Panagopoulou¹  Ioannis Karakassis¹  Stephen J. Morreale¹  Thomas Riggall¹  Dimitris Margaritoulis¹  James R. Spotila¹  Susan S. Kilham¹  Samir H. Patel¹ 

关键词: Gulf of Gabès;    Aegean Sea;    Crete;    Overfishing;    Eutrophication;   

DOI  :  10.3354/meps11433

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Foraging success affects reproductive output in sea turtles, and is therefore an important factor to measure in order to understand population dynamics. During 2010 and 2011, we used satellite telemetry to track the at-sea behavior of 20 post-nesting loggerhead turtles Caretta caretta from Rethymno, Crete, Greece. Nineteen transmitters provided location and dive data throughout the turtles’ migration towards their foraging grounds and the transition into foraging behavior. We identified 3 foraging regions: (1) 9 turtles migrated southwest towards the North African coast, with 8 concentrated in the region of the Gulf of Gabès, Tunisia; (2) 6 turtles migrated north towards the Aegean Sea; and (3) 4 turtles did not take long-distance migrations, instead remaining resident within the waters of Crete. Two fitness proxies were associated with differences in post-nesting strategies. Turtles foraging in northern waters had significantly larger curved and straight carapace lengths and clutch sizes than turtles foraging near Crete or Africa. Those differences reflect the disparity in benthic prey abundances among the 3 regions. The Aegean had a higher abundance of macrobenthic fauna than the other 2 regions, and the Gulf of Gabès had an increased level of eutrophication. Deterioration of the aquatic resources in the Gulf of Gabès region may be a contributing factor in the observed steady decline in clutch size and total nests per season in 2 critical nesting beaches for loggerheads in Greece.

【 授权许可】

Unknown