Sea turtle nesting season is officially underway. This year, researchers are beginning a new tagging study to learn more about the nesting habits of turtles coming ashore on Sanibel and Captiva Islands.
The Sanibel Captiva Conservation Foundation has two new staffers this season patrolling the beaches at night and applying flipper tags to female sea turtles coming ashore to nest. “When we encounter a female we’ll watch her and wait for her to completely finish the nesting process so we don’t interrupt,” said SCCF Sea Turtle Program Coordinator Kelly Sloan.
“Then we’ll apply a metal flipper tags on each one of her front flippers and we also insert a pit tag which is just like a microchip you’d put in your cat or dog.”
Data collected through the tagging effort will be compared with that of ongoing tracking studies by Mote Marine Laboratory in Sarasota and by the Conservancy of Southwest Florida on Keewaydin Island in Collier County.
“We’re positioned kind of right in the middle of those two projects,” said Sloan, “So we’ll be able to kind of collaboratively look at tag returns to see how much movement there is by sea turtles in those three beaches.”
Genetics data indicates San Carlos Bay in Lee County is the separation line between two genetically distinct subpopulations of Loggerhead sea turtles. This research could help refine exactly where that boundary exists.
“Our results will be a really good way to double check the preliminary genetics data,” said Sloan. “Based on the data we’d expect to see more turtles from Mote on Sanibel even though Keewaydin’s a lot closer, but we’ll just have to wait and see.”
The tagging study could also help explain a recent surge in nesting on the east end of Sanibel. That includes a roughly five mile stretch of beach between the Sanibel Lighthouse and Tarpon Bay Road which historically has not been a popular spot for sea turtle nesting.
“The average number of nests laid on that beach has been only been about 38 nests over the past 20 years or so,” said Sloan. “But in recent years there’s been a huge spike in nesting numbers on the east end and last year we actually had 120 documented nests on that beach which is more than triple the 20 year average.”
Sloan said the east end of the island could be becoming a more preferable spot, prompting turtles to switch there from other beaches. Sloan said it could also be an indicator of the success of decades of conservation efforts and that the surge in nesting activity could be females who’ve recently reached reproduction age choosing the east end of Sanibel to nest.
After nearly a decade of low numbers of nests, female turtles have been coming ashore in Southwest Florida in increasing numbers since 2012. Biologists are cautiously optimistic about the increased nesting activity, but say it hasn’t been going on long enough to constitute a new pattern.
Nesting season began May 1 and runs through October 31. Due to early nesting activity in recent years, the Florida Fish and Wildlife Conservation Commission recommended that beach monitoring efforts begin April 15 this year. A nest laid on Sanibel April 22 was the first documented sea turtle nest this season on Florida’s west coast.
“We actually did have three nests laid before the May 1st start date. So, it was a good thing we got out on the beaches early,” said Sloan. Local sea turtle protection ordinances didn’t go into effect until May 1, but Sloan says that could be moved up in future years.
During nesting season residents and visitors are reminded to shield or turn off lights visible from the beach, remove furniture from the beach at night and to fill in holes dug in the sand. Sloan says to avoid approaching or disturbing any nesting turtles and to make sure the flash is off before taking photos.
Breeding sea turtles are close to the shore this time of year making them more vulnerable to injuries from boat strikes. Boaters are advised to be vigilant about possible sea turtles near the surface.
