Climate effects on hatching success and emergence rate of leatherback turtle nests at Playa Grande, Costa Rica

PILAR SANTIDRIÁN TOMILLO; VINCENT S. SABA; GABRIELA S. BLANCO; CHARLES A. STOCK; FRANK V. PALADINO; JAMES R. SPOTILA

San Diego, California, USA

Simposio; 31st Annual Symposium on sea turtle Biology and Conservation; 2011

International Sea Turte Siciety

The weather in the Northwest coast of Costa Rica is characterized by a rainy season (May-October, ~232mm/month) followed by a pronounced dry season (December-April ~8mm/month). The local conditions in the area are strongly affected by el Nino Southern Oscilation (ENSO). During El Nino years, the weather conditions are hot, dry, and frequently result in droughts. Sea turtle nests need stable conditions of humidity and temperature dor egg developmnet and hatchling emergence. We analyze the effect of local weather conditions (pp and ambient temperature) on egg development and hatchling emergence of leatherback turtle (Dermochelys coriacea) nests between seasons 2004-2005 and 2009-2010 at Playa Grande, Costa Rica. Hatchling success and emergence rate were negatively affected by El Nino conditions because of low levels of rain and high temperature. Additionally, we used the ensamble of global climate model simulations contributed to the fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC) to project annual hatchling success and emergence rate over the next 100 years. Our projections show that hatchling output will dramatically decline throughout the 21st century because of dryer and warmer conditions predicted for the area of Central America where the leatherbacks nest. Our results suggest that similar effects can be expected on other sea turtle nesting beaches around the world where climate is likely to change to dryer and warmer conditions as a result of climate change