SANIBEL-CAPTIVA CONSERVATION FOUNDATION

The Sanibel-Captiva Conservation Foundation reported that from Aug. 3-5, Tropical Storm Debby brought around 4-6 inches of rain, high winds and storm surge to Sanibel and Captiva.

As of Aug. 7, SCCF biologists were still assessing impacts to sea turtle nests, using GPS coordinates with less than 3-centimeter accuracy to search for nests where stakes had washed away.

“Data from our moisture and temperature loggers indicate that some nests experienced a significant drop in temperature and increased moisture as the tide influenced the clutch,” Coastal Wildlife Director Kelly Sloan said. “The temperature in the nest displayed below dropped about 10 degrees during the storm.”

She reported that the timing of the storm was earlier than Hurricanes Idalia and Ian in recent years, which means there were still more than 500 nests incubating on the beaches, and there will likely be more washed out nests from Debby.

Late last August, Idalia led to over 100 sea turtle nest losses on Sanibel and Captiva. Ian in September of 2022 occurred when sea turtle season was already beginning to wind down, so the vast majority of nests had already hatched and been inventoried. There were 17 remaining nests when Ian hit, only one of which — a green sea turtle nest — survived but did not hatch.

SANIBEL-CAPTIVA CONSERVATION FOUNDATION Left, graphs show a spike in moisture content and drop in temperature at a loggerhead nest on Sanibel during Tropical Storm Debby on Aug. 4. Right, another loggerhead nest that experienced significant inundation for 12 hours and 15 minutes during Debby. This nest is still on the beach and Sanibel-Captiva Conservation Foundation biologists will monitor it daily for signs of hatch.

“It’s important to remember that storm season directly overlaps with sea turtle nesting season and is a natural part of their life cycle,” Sloan said. “Females have a nesting strategy that accommodates for storms — they lay multiple nests per season every 10-14 days so that even if one nest washes away, there’s a high likelihood that another one of her nests will produce hatchlings.”

The SCCF noted that while prolonged inundation can drown developing embryos or wash out eggs, brief wash overs can sometimes have a beneficial cooling effect.

As of Aug. 7, Sanibel and Captiva had 832 loggerhead nests, three green turtle nests and one leatherback nest for the year. A total of 12,856 hatchlings had emerged, including 12,816 loggerheads and 40 leatherbacks.

SANIBEL-CAPTIVA CONSERVATION FOUNDATION

SANIBEL-CAPTIVA CONSERVATION FOUNDATION