ESR 2:81-88 (2006)  -  doi:10.3354/esr002081

Demographic and health parameters of green sea turtles Chelonia mydas foraging in the Gulf of Carpentaria, Australia

Mark Hamann1,2,*, Chloe S. Schäuble1,2, Tom Simon3, Sammy Evans3

1Key Centre for Tropical Wildlife Management, Northern Territory University, Darwin, Northern Territory 0815, Australia
2School of Tropical Environment Studies and Geography, James Cook University, Townsville, Queensland 4811, Australia
3C/- Mabunji Aboriginal Resource Centre, Borroloola, Northern Territory 0854, Australia

ABSTRACT: It is becoming increasingly apparent that the development of management initiatives for sea turtles depends on the collection of biological data at all life stages. Substantial gaps include a lack of data on both the population’s demographic structure and reference values for biochemical parameters that can be used to assess the health and condition of sea turtle populations. Here we present comparative data on population demographics and biochemical blood parameters for green sea turtles Chelonia mydas in their foraging grounds of the Sir Edward Pellew (SEP) Islands in the Gulf of Carpentaria, Australia. Turtles within the adult size range for Australian green turtles comprised 54% of turtles caught. Of the turtles with curved carapace lengths (CCL) greater than 85 cm, 41 were adult males, one was an adult female, and 15 could not be confidently sexed. Continued surveys are needed to distinguish between the potential causes underlying this male-biased sex ratio and the difference between the sex ratio we found and those previously published for the population. Based on biochemical analysis of blood, green turtles in the SEP foraging grounds appeared to be healthy. However, mean levels of glucose and magnesium were generally lower than the ranges observed in other studies of clinically healthy green turtles. Additionally, glucose levels were lower in turtles with CCLs of over 85 cm.


KEY WORDS: Green turtles · Chelonia mydas · Health · Demography · Gulf of Carpentaria


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