Environmental change can affect the SEX ratios that are produced in species that have temperature dependent SEX determination such as sea turtles, but the severity of the direct impacts of these…

The National Oceanic and Atmospheric Administration (NOAA) awarded the University of Massachusetts a cooperative agreement valued at $710,664 under the Cooperative Research Program (CFDA 11.472) to conduct research on sea turtle population viability in response to environmental change. Effective from March 1, 2025 through February 29, 2028, this award supports applied research utilizing novel epigenetic DNA methylation markers to determine the sex of Hawaiian green turtle hatchlings through minimally invasive sampling techniques. The project leverages existing biological samples and in situ nest temperature data previously collected from Hawaiian green turtle populations to quantify primary sex ratios and assess population resilience under projected environmental conditions.

The research products generated under this award will provide critical data on how temperature-dependent sex determination affects sex ratio outcomes in economically important sea turtle populations. By applying the newly developed epigenetic sexing methodology to Hawaiian green turtles and comparing findings with other regional populations, the study will establish relative risk assessments and resilience projections for these protected marine resources. The resulting datasets and analyses will directly inform optimal management strategies for marine protected species and contribute to the biological science research objectives established under NOAA's Cooperative Research Program.

Environmental change can affect the SEX ratios that are produced in species that have temperature dependent SEX determination such as sea turtles, but the severity of the direct impacts of these environmental changes and how they will impact population viability are currently unclear. We recently developed novel epigenetic (DNA methylation) markers to SEX hatchlings using minimally invasive skin and blood sampling in sea turtles; here we apply these markers to hawaiian green turtles (chelonia mydas), using existing samples that have been collected in conjunction with in situ nest temperature data. This work will be informative for quantifying the recent primary SEX ratios of hawaiian green turtles specifically, and the data generated can be compared to other populations to understand relative risk and resilience of these economically important populations under projected environmental change.