May 10, 2021 — Because of global warming, most newborn sea turtles are female, which could put their long-term survival at risk. New research reveals that in addition to more widely used techniques such as shading and irrigation, the splitting of the turtle nests, which has not been tried before, could even out the sex ratio of turtle hatchlings.
Scientists also argue that to increase the resilience of sea turtles, turtle conservation must address threats beyond climate change, including ocean pollution, unsustainable fishing and illegal wildlife trade.
Understanding turtle reproduction
While the sex of mammal offspring is determined genetically, certain reptile groups such as crocodilians, lizards and turtles rely on temperature-dependent sex determination, or TSD, meaning that the gender of the hatchling would depend on the egg’s incubation temperature.
According to the National Oceanic and Atmospheric Administration (NOAA), sea turtle eggs which incubate below 81.86 Fahrenheit – around 28 Celsius degrees – will typically hatch into a male baby, while incubation temperatures above 87.8 Fahrenheit – 31 Celsius degrees – would tend to produce female hatchlings.
Temperatures that fluctuate between the two would result in a mix of female and male baby turtles, while extreme temperatures beyond this range could lead to embryo malformation and higher mortality rates. The exact range might also vary slightly based on the type of sea turtle or the location of the nesting beach.