Science Daily - Oz Sea Turtle Nesting Grounds "Already Producing More Females"

[hatrack]

ScienceDaily (Oct. 8, 2010) — The "turtle and dugong capital of the world," the northern Great Barrier Reef (GBR) and Torres Strait region, faces increased pressure under climate change from human actions such as fishing, hunting, onshore development and pollution. "Depletion of turtle and dugong numbers increases their vulnerability to other threats and lowers their ability to cope with climate change," Dr Mariana Fuentes of the ARC Centre of Excellence for Coral Reef Studies and James Cook University will tell the Coral Reef Symposium in Canberra October 8.

Dr Fuentes says that turtles in particular are vulnerable to the effects of climate change, which include decreases in hatching success, loss of nesting areas and overheated beaches, which will decrease the turtles' reproductive output and may significantly alter the sex ratio of their offspring. Dr. Fuentes' research into the green, hawksbill and flatback turtles and well as dugongs in the northern GBR and Torres Strait is seeking to establish priorities for the management of marine megafauna to increase their resilience to climate change.

"Managers face the challenge of addressing the direct effects of climate change, as well as ongoing threats that dugongs and sea turtles face throughout their geographic range," she explains. "For logistical, financial and political reasons, managers cannot address all threats simultaneously, and so need to prioritize their actions.

Of particular concern is the effect of climate change on the gender balance of turtle population, Dr Fuentes says: "The temperature of the beach sand determines the gender of the hatchlings -- warmer sand produces more females while cooler sand produces more males. Under current conditions the nesting grounds are already producing more females. With an increasing temperature, these turtles are at risk of stretching out the ratio, though we can't yet predict exactly when it will cause an unbalanced population."

EDIT

http://www.sciencedaily.com/releases/2010/10/101008082926.htm