Age at size and growth rates of early juvenile loggerhead sea turtles (Caretta caretta) in the Mediterranean based on length frequency analysis

Growth rate is a fundamental parameter in understanding sea turtle population dynamics and is also important for the conservation of these threatened species. It can be influenced by both environmental and genetic factors, and thus it can vary according to the area. Growth rates and age at size of loggerhead turtles (Caretta caretta) are estimated for the first time in the Mediterranean sea and in particular for the elusive first period of life, through length frequency data from 88 turtles ranging from 6.4 to 30 cm curved carapace length found in Italian waters. A visual examination of the length distribution of small turtles found in pelagic habitats suggests a preliminary growth curve for early juveniles in the Mediterranean. Results indicate that this size range includes turtles in the first four years of life. Growth rates ranged from 11.8 cm/yr in the first six months of life to 3.6 cm/yr at the age of 2.5-3.5 years and are similar to those estimated from the Atlantic. Results also suggest a secondary increase in growth rates in larger turtles recruiting to neritic habitats, supporting a polyphasic growth pattern proposed for other populations and other sea turtle species.