Girls Rule the Beaches

How Rising temperatures feminize sea turtles.

The sex of a marine turtle is determined by temperatures in the nest (incubation). Warming trends are causing a higher production of female hatchlings (Patino-Martinez, et. al., 2012). Eventually this imbalance may cause fitness levels of turtle populations to diminish.

Sex ratios for sea turtles are known to be biased toward females, already at 90%. If temperatures continue to rise, male production could be completely eliminated. “Populations of turtles in more southern parts of the United States are currently highly female biased and are likely to become ultra-biased with as little as 1°C of warming and experience extreme levels of mortality if warming exceeds 3°C” (Hawkes, et al., 2007. P.923).

In addition to feminization, sea turtles face many more problems arising from climate change (e.g. loss of nesting beaches from rising water; changes in reproductive periodicity, changes in ranges, predation by invasive species). Check this link for an article on sea turtles in Australia and how they are responding to climate change.

Here is a video on climate change in general.

You can research all of these topics from the library home page.

References: (citations are not in any particular format)

HAWKES, L. A., BRODERICK, A. C., GODFREY, M. H. and GODLEY, B. J. (2007), Investigating the potential impacts of climate change on a marine turtle population. Global Change Biology, 13: 923–932.

Patino-Martinez, J., Marco, A., Quiñones, L. and Hawkes, L. (2012), A potential tool to mitigate the impacts of climate change to the caribbean leatherback sea turtle. Global Change Biology, 18: 401–411. doi: 10.1111/j.1365-2486.2011.02532.x

M.M.P.B. Fuentes, M. Hamann, C.J. Limpus, Past, current and future thermal profiles of green turtle nesting grounds: Implications from climate change.  Journal of Experimental Marine Biology and Ecology, Volume 383, Issue 1, 31 January 2010, Pages 56-64, (http://www.sciencedirect.com/science/article/pii/S0022098109004663) 

image credit: Diane Arrieta. Green turtle. Jupiter, Island, FL , 2012.