Graeme Hays Ph.D.

Deakin University


I am an ecologist with long-standing interests in the use of satellite tracking to examine marine animal movements and the impacts of climate change on marine systems.

Working closely with Dr. Nicole Esteban, my current work in the British Indian Ocean Territory (BIOT) includes equipping adult and juvenile hawksbill and green turtles with satellite tags. The long-term tracks show that some individuals may both breed and forage within the Marine Protected Area (MPA), while others may conduct very long distances migrations, sometimes with journeys to distant foraging sites in Africa, Madagascar the Seychelles and the Maldives.

Sea turtles have temperature dependent sex determination, with warmer incubation temperatures producing female hatchlings and cooler temperatures male hatchlings. Therefore, our long-term records of sand temperature on nesting beaches in BIOT are being used to assess likely hatchling sex ratios. Our results revealed that the shading of nests by vegetation behind beaches, helps to reduce incubation temperatures and ensures that fairly equal numbers of male and female hatchlings are being produced. The impacts of warming temperatures associated with climate change are also being examined.

Some of the turtles nesting in BIOT conduct migrations of many 1000s of km, the MPA provides a nesting sanctuary for turtles feeding across the western Indian Ocean.

Graeme Hays


2013 Present
Professor of Marine Science, Deakin University
2005 2015
Professor of Marine Biology, Swansea University

My Project

  • Sentinel Species Research
    The Ecology of Sea Turtles in the British Indian Ocean Territory

Other interests

I am collaborating with a large number of scientists around the world to compare the patterns of movement across multiple taxa including sea turtles, sharks, marine mammals and birds.

My Publications