SANIBEL-CAPTIVA CONSERVATION FOUNDATION

On June 28, the Sanibel-Captiva Conservation Foundation’s sea turtle team documented the hatching of a rare, endangered leatherback nest on Sanibel’s west end. During the inventory of the nest, SCCF biologists and permitted volunteers documented 113 eggs, including 40 emerged hatchlings.

The SCCF reported that it has only recorded leatherback nesting in three previous years: 2009, 2015 and 2020. Leatherback nesting on the Gulf coast of Florida is rare and mostly sporadic — on average representing only a few of more than 1,000 nests laid per year in the state.

“Most leatherback nesting occurs on the east coast of Florida, primarily in Martin and Palm Beach Counties,” Coastal Wildlife Director Kelly Sloan said.

Like this season, the 2009 and 2015 seasons each only had one nest, but in 2020, six nests were laid across Sanibel and Captiva. Several others were documented along the central/southwest coast, as well.

Also in 2020, the first leatherback was satellite-tagged on the Gulf coast in partnership with Florida Leatherbacks Inc. It was given the name “Juniper.” By the time Juniper was tagged during night survey work, there were already three leatherback nests on the islands. After her tagging, the team was able to confirm that she nested several more times — on Sanibel, Captiva and Cayo Costa.

FLORIDA LEATHERBACKS INC Tracking by Florida Leatherbacks Inc. in 2020 after satellite tagging, in partnership with the Sanibel-Captiva Conservation Foundation, during night survey research.

In 2020, Captiva’s first leatherback nest was documented and inventoried, with 51 hatchlings successfully emerging out of 89 eggs total. It was the only one of the six nests that successfully hatched on the islands. The six nests had a combined total of 504 eggs, but no emerged hatchlings were documented from the other five nests.

The SCCF noted that compared to the other six sea turtle species, leatherbacks tend to have lower average hatch success, and the variables associated with it are a continued topic of research statewide.

After her last nest on June 17, 2020, Juniper was tracked wandering up and down the Gulf coast, traveling about 2,300 miles. Her tracker stopped sending a signal shortly after that.

THIRD LEATHERBACK NEST HATCHING

With an average of 700 loggerhead sea turtles nesting on Sanibel and Captiva from May to October, this year’s leatherback nest also marked only the third time that the SCCF team has documented leatherback hatchlings on the island’s beaches.

SANIBEL-CAPTIVA CONSERVATION FOUNDATION A leatherback hatchling on Captiva in 2020.

In 2009, the SCCF documented the hatching of a leatherback nest on Sanibel’s east end. It was the first known leatherback nest in all of Lee or Collier counties. Ninety hatchlings successfully emerged from a total of 106 eggs.

The leatherback nest laid on the west end of Sanibel in 2015 did not hatch after washing over nine times. The nest inventory found a total of 57 unhatched eggs and six spacer eggs.