Tracking and analysis of the spatial and thermal habitats of inter-nesting loggerheads (Caretta caretta) in Kyparissia Bay, Greece

Thomas F Backof, Purdue University

Abstract

Loggerhead sea turtles (Caretta caretta) are globally endangered cold blooded reptiles which return to the same beach to nest, making each distinct beach and population important for species survival. Time spent between nesting attempts is referred to as the inter-nesting period and is a short but vital part of a turtle's life. Determining where turtles spend the vulnerable inter-nesting period is of great importance for the conservation of individual rookeries. The second most important loggerhead rookery in the Mediterranean Sea is found at Kyparissia Bay, Greece, with increasing nest numbers and no national park protection. Kyparissia Bay is unique in its geography and bathymetry, as it is near the northern extreme of nesting beaches, is very deep, and is open to the Ionian Sea. These conditions result in homogenous water that is colder water than many comparable nesting beaches, but warms up as the season progresses. This study, in conjunction with ARCHELON, the Sea Turtle Protection Society of Greece, investigated the inter-nesting habitat of female loggerhead turtles nesting along Kyparissia Bay through the use of temperature-depth data loggers, radio transmitters, and satellite transmitters. Data loggers were deployed directly on the rear marginal scutes of the carapace, and transmitters were secured using a towed attachment method from the same area. Turtles remained at or near the surface for the entire inter-nesting period (95.1 percent of time was spent shallower than two meters). Inter-nesting turtles behaved differently from the beginning to the end of the season, in response to increased temperatures later in the year. Later season, warmer individuals were able to dive deeper, travel farther, and had shorter duration inter-nesting periods than earlier turtles in cooler conditions. Two post nesting migrations were also documented; one from Kyparissia Bay to the Aegean Sea and one to the center of the western Mediterranean Sea, north of Algeria.

Degree

M.S.

Advisors

Paladino, Purdue University.

Subject Area

Wildlife Conservation|Biology|Conservation

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