Leatherback sea turtle (Dermochelys coriacea)

Leatherback sea turtles will be sensitive to climate change through a number of pathways. Turtles may respond directly to increases in temperature by shifts in sex ratios; warmer temperatures promote higher levels of female young. Increases in sea surface temperature could also lead to changes in migration patterns, northward species shift, and alterations in nesting and hatch timing, which could prompt mismatches between turtle abundance and prey availability. While possible, jellyfish populations have been on the increase, so a negative effect here is uncertain unless the species composition of the sea jellies involved is less favorable or unfavorable. Increases in sand temperature could lead to higher levels of hatchling mortality. Indirectly, increases in sea surface temperature and potential changes in upwelling and ocean circulation could affect the jellyfish that leatherbacks tend to prey upon and limit prey availability. Turtle nesting habitat may also be impacted by sea level rise, increased storms, and coastal inundation, which could lead to lower reproductive success. Susceptibility to storm-related threats may vary by species such that species with lower nest-site fidelity, like leatherbacks, would be less vulnerable than sea turtles with higher site fidelity. The broad migratory range of leatherbacks may allow them to search out different suitable nesting habitat; leatherbacks have low nest-site fidelity and thus may be able to switch nesting sites depending on conditions (although nesting occurs outside of Washington State). With an increase in mean air, and therefore beach sand temperatures, previously unsuitable habitat, for example beaches at higher latitudes than current nesting areas, may become suitable. Leatherback turtle nests are now being recorded at their most northerly in a decade of monitoring. However, data are lacking on how quickly leatherbacks will be able to take advantage of these changes.