SEA TURTLE AND CLIMATE  CHANGE

Sea turtles are creatures that use marine and terrestrial habitats. Therefore, climate change have much broader effects on sea turtles than many other species.

One dominant effect of climate change is losing habitats. As the global temperature increases, icebergs melt and sea levels rise. The projected sea level rise in the end of the 21st century ranges from 0.18 to 0.59 meters. However, even subtle rise in sea levels could lead to a large number of loss of beaches, which are used as habitats for sea turtles. More severe storms caused by climate change also increase beach erosion rates.

Not only are beaches constantly disappearing, but the temperature of sands in beaches is also increasing due to climate change. Sea turtles are reptiles, which means that the gender of the hatchling is determined by the temperature of sands in which the egg incubates. Generally, the gender of hatchling is male if the egg incubates in the cooler part of the nest, and the gender of hatchling is female if the egg incubates in the hotter part of the nest. Therefore, hotter sands directly influence the proportion of hatchling genders. In fact, sea turtles nesting on the beaches at Playa Grande on Costa Rica’s Pacific coast are already hatching 70 to 90 percent of females, varying depending on the year.  

Climate change also plays a role in changing ocean currents, which are used for sea turtle to migrate and find preys. By changing the direction of ocean currents, climate change influences the distribution and abundance of preys, which makes sea turtles much harder to find preys. Changes in currents also force sea turtles to change their movements and possibly change their nesting timing.