July 2, 2012
Global Warming Could Wipe Out Endangered Turtle Populations
redOrbit Staff & Wire Reports - Your Universe Online
The largest and most critically endangered species of sea turtle could be wiped out by the end of the century due to global climate change, claims a new study published Sunday in the journal Nature Climate Change.In the study, researchers from Drexel University, Princeton University, and other institutions and government agencies discovered that eastern Pacific populations of these turtles could be affected by warming trends resulting in hotter, drier beaches.
Leatherback turtles are already at risk due to a combination of current and past threats, including egg poaching, but such extreme conditions could place their eggs and hatchlings at risk. If actual climate patterns follow the modules used in the study, resulting in a possible 75% decline in their population by the year 2100.
"We used three models of this leatherback population to construct a climate-forced population dynamics model. Two parts were based on the population's observed sensitivity to the nesting beach climate and one part was based on its sensitivity to the ocean climate," lead author Dr. Vincent Saba, a research fishery biologist with the NOAA National Marine Fisheries Service Northeast Fisheries Science Center, said in a statement.
While the number of leatherback turtle births fluctuate annually based on variations in climate, with more hatchlings born in cooler, rainier years, the researchers said. Female turtles are more likely to return to Pacific nesting beaches when there are more jellyfish to eat, which happens during cooler seasons, and turtle eggs and hatchlings are less likely to survive during warmer, drier seasons.
"The researchers applied Saba's combined model of these population dynamics to seven climate model projections assessed by the Intergovernmental Panel on Climate Change (IPCC)," the university said. "The climate model projections were chosen based on their ability to model El NiÃ±o Southern Oscillation (ENSO) patterns on the temperature and precipitation in the region of Costa Rica where this team has conducted long-term leatherback studies."
"The resulting projections indicate that warmer, drier years will become increasingly frequent in Central America throughout this century. High egg and hatchling mortality associated with warmer, drier beach conditions was the most significant cause of the projected climate-related population decline: This nesting population of leatherbacks could decline by 7 percent per decade, or 75 percent overall by the year 2100," they added, noting that the population was already "critically low" at this time.