Baby sea turtles face a famous gauntlet. The little reptiles are vulnerable to predators, poachers, fishing gear and plastics. And now with climate change, there’s one more hurdle on that list: unusually hot sand.
Scorching sand heats up turtle nests, which are buried in pits on beaches. Those elevated temperatures can cook developing embryos. “In some places the nests are getting so hot that there’s no survival,” says marine biologist Kristin Mazzarella of Mote Marine Lab in Sarasota, Florida. “The eggs don’t hatch.”
In the short term, most turtle species can cope with a little extra warmth. But in the long game, overheating nests could be a serious burn for these ancient ocean reptiles.
Turtles in trouble
Lately beaches have been getting hotter, thanks to man-made climate change. Warming is projected to continue into the next century, heating up beaches around the world. Sea turtles will keep nesting along those hotter shores, but their eggs will do worse and worse as temperatures rise, scientists say.
“We’re seeing more dead eggs,” says sea turtle biologist Jeanette Wyneken of Florida Atlantic University in Boca Raton. “And when we do get turtles hatching,” she adds, “they’re often heat stressed: They may hatch and crawl to the water, but then die.”
Turtle nests once did well in Boca Raton. Somewhere between 78 and 81 percent of loggerhead, green, and leatherback sea turtle eggs hatched on average in the past, Wyneken says. But record heat ravaged the nests in the last two years. In 2015, only 58 percent of eggs hatched, she says. Last year, that number was down to just 38 percent.