Hamann et al., 2007:

There is a high probability that exposure to changes to increased air and sea surface temperatures will affect marine turtles in two broad areas, reproduction and foraging ecology.

[The] "major vulnerability for marine reptiles to climate related events is related to increased air and sea temperatures. Each of the marine reptile groups comprise tropical or subtropical species that are adapted for life in warmer climates and they have historically experienced time periods of warmer temperatures and vastly different coastal geomorphology. However, the contemporary question is how these species will cope with increased temperature in conjunction with numerous other threatening processes. Essentially if average seasonal sand temperatures at marine turtle nesting beaches consistently rise above 30°C they are likely to impact embryo development through alterations to sex ratios (in favour of females), phenotype or through direct mortality. If they consistently rise above 33°C alterations to the success of embryo development and changes to the phenotype of emerging hatchlings are likely. Increased temperatures are likely to have a similar impact on the incubation of estuarine crocodile eggs, but the thresholds are more difficult to quantify. Likely responses to these impacts include shifts in the timing of the nesting season and shifts in nesting locations (this could also arise from sea level rise)."

Figure 15.3: Operating temperature parameters for marine turtles. MBTF represents minimum body temperature for feeding (except leatherback turtles); MSTR represents mean selected temperature range.