The Loggerhead Turtle, Caretta-Caretta, in Queensland - Population Breeding Structure

Abstract

Population models proposed as a result of independent tagging programs of nesting Caretta caretta in Queensland are in disagreement about the size of discrete breeding units. An electrophoretic survey was conducted to assess the relevance of genetic variation as revealed by electrophoresis to the investigation of Caretta caretta population breeding structure. Low level electrophoretic variability (H*L(obs) = 0.016) was found. The geographical distribution of alleles, when compared with tag-recapture data and other aspects of life history, indicated that discrete breeding populations of C. caretta in Queensland are larger than previously thought. C. caretta nesting on the mainland beaches and on the cays of the Capricornia Section of the Great Barrier Reef Marine Park form a panmictic population. The data indicate that those nesting on the Swain Reefs cays do not interbreed with the mainland-Capricornia breeding population.