From Feb. 13-21, SCCF documented one live and five dead stranded sea turtles on Sanibel.

All stranded turtles were identified as loggerheads (Caretta caretta) and consisted of three adult males, two adult females, and one subadult. The live turtle was an adult female found floating near the shore, making seemingly no effort to swim. Staff were able to rescue the turtle and transport it to MOTE Marine Laboratory & Aquarium in Sarasota to be evaluated and rehabilitated.

“The turtle had no obvious external injuries to determine the cause of stranding, but was extremely lethargic,” said SCCF Sea Turtle Biologist Amanda Manrique. “Two of the five dead turtles also lacked any external injuries to indicate cause of stranding. Two adult male turtles were found with blunt force trauma likely caused by vessel strikes, and a subadult was found with apparent predation injuries, possibly from a shark.”

The cause of stranding for turtles with no evidence of physical trauma is not definitive without further testing, but could potentially be related to the recent red tide blooms off the coast of Sanibel and Captiva, Manrique said.

“Sea turtles can be affected by brexetoxins (red tide toxins) through ingestion of contaminated prey items, such as crabs, sponges, and mollusks,” said SCCF Sea Turtle Biologist Savannah Weber. “There’s often a lag between initiation of a red tide bloom and sea turtles stranding due to the time it takes for toxins to accumulate in prey items.”

In 2024, SCCF documented 17 total sea turtle strandings.

Learn more about how red tide can affect wildlife, even when there’s not an active bloom.

Brevetoxins can affect a sea turtle’s nervous system, causing the turtle to become weak or lethargic and could eventually lead to death. This may result in the turtle floating at the surface of the water and becoming vulnerable to predators or vessel strikes. 

SCCF-led research indicates that even when red tides do not cause direct mortality of exposed wildlife, they can act as a physiological stressor with long-term impacts on sea turtle health. Toxins in nesting females are also transferred to their offspring. This possibly affects hatching rates and hatchling survival. Collaborators on this research include Loggerhead Marinelife Center, the Florida Wildlife Research Institute, University of Florida, Fishhead Labs, the University of Miami, and the Everglades Foundation.

Report any suspected sea turtle strandings to SCCF’s sea turtle hotline at 978-728-3663 (978-SAVE-ONE). Report other wildlife behaving erratically (unable to stand or fly, displaying tremors, apparent weakness or confusion) to Sanibel’s Clinic for the Rehabilitation of Wildlife (CROW), by calling the CROW Wildlife Hospital at 239-472-3644 ext. #222.