Climate change implications in the suitable habitat of olive ridley turtle Lepidochelys olivacea in the Eastern Tropical Pacific

Abstract

The olive ridley turtle Lepidochelys olivacea is one of the most abundant marine turtle species, but its populations are threatened by various environmental changes, including climate change. Understanding how the marine environment influences it is crucial for conservation efforts. This study models the habitat suitability of L. olivacea in the Eastern Tropical Pacific, a region of significant ecological importance for its nesting and foraging activities. We used remote sensing data from 59 individuals tagged in Panama and Costa Rica between 2009 and 2018. The response was modeled with MaxEnt, using a presence-only approach and environmental variables including sea surface temperature, ocean mixed layer thickness, chlorophyll-a concentration, and current velocity. We categorized months into warm (El Niño) and cold (La Niña) conditions, providing insight into climate change effects. Results reveal that chlorophyll-a concentration and sea surface temperature best predicted the presence of L. olivacea. The intertropical convergence zone exhibited high habitat suitability, especially in the Central Pacific. During El Niño, suitable habitat declined, primarily along coastlines, while, during La Niña, it expanded, favoring oceanic waters and temperate temperatures in upwelling zones. These findings suggest climate change could significantly impact L. olivacea distribution, potentially shifting nesting and foraging areas.