It’s clear that sea turtles have arrived on Sanibel and Captiva, with the SCCF sea turtle team recently documenting the 100th sea turtle nest this season. As of today, 136 nests have been found on the islands.
“From lots of requests for pink flags for volunteers to mark off nests, to making sure the UTVs are stocked with nest screens, to our morning surveys encroaching upon the early afternoon, it’s clear that more turtles have arrived,” said Sea Turtle Biologist Jack Brzoza. “Each beach has had a substantial increase in activity, and our current nest count has tripled over the last week."
Most of the nests have been laid by loggerhead sea turtles (Caretta caretta), while three were laid by green sea turtles (Chelonia mydas). Typically, green sea turtles start nesting later than loggerheads, but they've started nesting a bit earlier in recent years, said Coastal Wildlife Director and Sea Turtle Program Coordinator Kelly Sloan. The first one of 2023 was found on May 12.
A green sea turtle heading back to sea. Photo by Alex Horn
Last year, 17 nests of a total 786 were laid by green sea turtles. They are more commonly found nesting along the south-central east coast of Florida.
"It won’t be too long before we begin to see hatchlings emerge," Sloan said.
In addition to morning nest monitoring, SCCF’s sea turtle team also conducts an annual nighttime tagging project, which includes nightly, sunset-to-sunrise beach patrols in search of nesting females.
During nighttime patrols, sea turtles are checked for tags. If none are present, staff apply a flipper tag — placed on a scale located on the turtle’s front flippers — and a Passive Integrated Transponder (PIT) tag on the turtle. These tags allow biologists to see an individual sea turtle’s nesting and movement patterns, which can help inform research and conservation.
A green sea turtle tagged with a satellite tag.
Many encountered turtles are repeat visitors to Sanibel and already have tags — but most haven’t been to the island in a couple years since loggerheads typically only nest every two to three years.
“On our very first night, we encountered five turtles who already had tags – two of them twice,” Sloan said. “Ligonberry had previously only been seen once in 2019, and we observed her during a false crawl and then a nest. Coconut has been seen in 2017 and 2019, and Banded Tulip is a frequent nester, observed in 2016, 2018, 2020, and now 2023!”
Since SCCF’s tagging project began in 2016, staff have encountered nearly 930 unique individual sea turtles.