Sea Turtles on Cumberland Island
Cumberland Island’s undeveloped shoreline attracts the largest number of nesting sea turtles in the state of Georgia. Most travel hundreds or thousands of miles to return near the area where they were born (a trait known as natal homing).
Once they reach their home waters, pregnant females wait offshore for the perfect moment to come on shore and lay their eggs. During nesting season, one female will lay between 3-6 clutches; however, only one of every 1,000 sea turtle hatchlings is likely to survive to adulthood, and it will take up to 30 years for each one to actively reproduce (depending on species).
Four species of endangered sea turtles are known to nest on Cumberland Island:
- Leatherback turtle
- Green turtle
- Loggerhead turtle
- Kemp’s ridley
Did you know?
The loggerhead turtle (scientific name: Caretta caretta) is listed as a protected species under the Endangered Species Act. The Georgia population of loggerhead sea turtles, including that on Cumberland Island, is a separate sub-population and genetically distinct from the more numerous Florida loggerhead population -- one which is increasingly threatened by loss of nesting habitat and increased depredation of its nests and hatchlings.
Both raccoons and feral hogs prey on the incubating eggs and hatchlings of sea turtles. The National Park Service and Georgia Department of Natural Resources are mandated to protect Cumberland Island’s sea turtles from feral hogs, raccoons, and other predators.
In 2000, feral hogs and raccoons depredated 117 nests (or 65%) of all eggs laid by loggerhead sea turtles on the island. Elimination is acknowledged to be impossible, so the NPS operates an on-going reduction program and controls raccoons where they become a problem.
Volunteers work the Georgia coastline each summer to mark and protect new nests; this often involves placing a screen over newly-laid nests, or relocating nests that may be too close to the water or in erosion zones.
Beach driving is allowed along the entire 17-mile beach of Cumberland Island. The Georgia Department of Natural Resources has issued over 350 permits to island residents and family members to drive the beach, posing a potential danger to hatchlings.
In the waters offshore, sea turtles face severe threats from the shrimping industry. Shrimp trawl nets have resulted in the deaths of thousands of sea turtles that have washed ashore on Cumberland Island. Trawling nets are now equipped with what’s known as turtle-excluder devices (TEDs), which were designed to minimize the shrimping industry’s impact on these species. They do facilitate the release of smaller-sized passive turtles.
Many of the ocean areas where loggerheads migrate for food and nesting are, unfortunately, the same areas used to catch commercial seafood. Juvenile loggerheads are often caught in the longline fishery (an oceanic fishery outside Georgia waters) and sexually mature adults are still getting caught in shrimp trawling nets. Between these two fisheries, tens of thousands of loggerheads continue to die each year (Our Sea Turtles, by Blair and Dawn Witherington, 2015).
A marine reserve adjacent to Cumberland Island would benefit this critical sea turtle habitat and the long-term viability of shrimping and other fisheries.