Sea turtle nest counts stable as hatchling disorientations are on the rise

Some shores of Manatee and Sarasota counties had record sea turtle nests, while others missed the mark, in an overall strong nesting season.

Anna Maria Island Turtle Watch counted a record 488 nests and estimated that more than 25,000 hatchlings emerged from Anna Maria Island and made it to the Gulf of Mexico. While this was only 53 more nests than in 2016, the number of false crawls — or when a sea turtle pulls itself onto the shore only to turn around without laying eggs — had been slashed nearly in half compared to the previous year.

Yet Mote Marine Laboratory’s patrol on a 35-mile stretch from Longboat Key to Venice fell shy of its record nest count. In the 2017 season, which runs from May through October, 4,503 nests of loggerhead and green sea turtles were counted. Loggerheads made up about 98 percent of its nest counts. But the record count remains at 4,588 in 2016, just 85 more nests than this year.

“It’s a different set of turtles, because (mature) turtles nest every two to three years,” Mote senior biologist Kristen Mazzarella said. “I think it’s great that the number is close to last year’s record-breaking year.”

Some areas in Sarasota had more false crawls than nests. A healthy beach, Mazzarella said, typically has a ratio of one nest to one false crawl. But she said there are a number of reasons why sea turtles would end up not laying eggs on a certain beach, whether it was physical limitations like an injury or escarpment from a beach renourishment project, or a swale that would give a turtle the impression that the beach was smaller than it was.

Even with Tropical Storm Emily and Hurricane Irma, there weren’t as many washed out nests as there had been last year.

“That means we probably produced more hatchlings than last year,” she said.

With more hatchlings, come more disorientations. On Anna Maria Island, Longboat Key, Lido Key and Venice, the number of baby turtles that had mistakenly trekked in the opposite direction of the water increased.

“The best thing we can do is to continue to educate people,” Mazzarella said.

As hatchlings emerge from their shells under the sand, they use light to direct them to the horizon and into the water. Even light pollution from a cell phone half a mile down the beach can cause a pack of baby turtles to follow, she said. Beachside residents are also asked to turn off their porch lights during turtle season.

Lights aren’t the only man-made interruption affecting sea turtles. Just over 100 sea turtles this season came into contact with beach furniture, with two of them dragging it with them back to the water. One of those pieces of furniture wasn’t tracked down, and Mote doesn’t know how long it could have stayed on the turtle.

Sea turtles caught in furniture could lead them to getting stuck underwater, she said. Not only could the turtle drown, but the furniture would contribute to marine debris that affects a number of species.

“We don’t want to just protect the turtles on the beach,” Mazzarella said. “We want to protect the oceans that they live in for the rest of their life.”

This story was originally published November 1, 2017 at 1:15 PM with the headline "Sea turtle nest counts stable as hatchling disorientations are on the rise."