New study on microplastic threat to loggerheads

Loggerhead hatchlings. Photo credit: US Fish and Wildlife Service

New evidence from a paper by researchers at Florida State University shows that loggerhead sea turtles may face yet another impact from plastic pollution: the incorporation of microplastics into the sand they use to construct their nests. In a survey of the 10 most important loggerhead nesting sites on the Gulf Coast of Florida, microplastics were found at every location. Sea turtles have what's called "temperature-dependent sex determination," which means the sex of hatchlings is determined by the temperature they are incubated at. Basically, at warmer temperatures, more (or all) of the hatchlings are female. Because tiny plastic particles retain heat better than grains of sand, shifts towards beaches with higher concentrations of microplastics are a potentially serious concern for the future health of loggerhead populations. Scientists have known for a long time (see this paper, or this one, or this one) that changes in beach temperature would impact sea turtle sex ratios, but we're just starting to reckon with the realization that the addition of plastics to sand may exacerbate these effects.

Yet another reason to get involved with the work of organizations working to remove trash from the marine environment, like our friends at Debris Free Oceans, and to avoid single-use plastics!