Tropical Storm Elsa’s strong southern winds caused 125 sea turtle nests on Sanibel and Captiva to lose their marking stakes and protective screens. Sea turtle staff members have been working diligently over the last week to confirm whether the eggs washed away, too, or if they are still buried in the sand.
Using highly accurate coordinates collected with a Trimble device, SCCF staff were able to confirm that 40 of the 85 nests that lost their stakes on Sanibel survived the extreme tidal action. However, 45 nests were completely washed-out on Sanibel, reports SCCF Coastal Wildlife Director Kelly Sloan. The assessment on Captiva is still underway.
Please remember that sea turtles have a nesting strategy that accommodates natural storm events. Female sea turtles deposit several nests throughout the nesting season, essentially hedging their bets to make sure that even if a hurricane or tropical storm hits during nesting season, there is a high probability at least a few of the nests will incubate successfully.
For instance, in early June 2020, TS Cristobal washed away 29 nests and, in September, TS Sally washed away 17 nests on Sanibel and Captiva. Yet, there were still a record-breaking 924 nests last year.
What happens to a nest during a storm?
SCCF data loggers captured the water level, temperature, and moisture changes inside 38 nest chambers during the tropical storm. It is evident that the storm surge and heavy rain caused the bottom of this particular nest to become inundated for about three hours. Nests can withstand some degree of wash-over during incubation but standing water can negatively impact hatching success.