Three species of endangered sea turtles nest on Cumberland:
- The leatherback turtle
- The green turtle
- The loggerhead turtle
On average, loggerheads construct 200-300 nests each year. Though nests on Cumberland Island represent 25-30% of total nests throughout the state, the number of nests has been steadily declining for several decades. However, 2010 was the best nesting year ever for loggerheads on Cumberland Island.
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, genetically distinct from the more numerous Florida loggerhead population and 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, with the raccoon presently being the principal predator.
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. However, elimination of feral hogs is acknowledged to be impossible at this time, so the NPS has an on-going reduction program for hogs, and controls raccoons where they become a problem.
In the past, loggerhead sea turtle eggs have suffered devastating losses. In 2000 feral hogs and raccoons depredated 117 nests or 65% of all eggs laid by loggerhead sea turtles on the island.
Only one of every 1,000 sea turtle hatchlings is likely to reach maturity. The depredation of nests—especially by feral hogs—can have significant long-term impacts on the survival of the loggerhead sea turtle so continual management of the hog population is imperative.
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 even greater threats from the shrimping industry. Trawl nets have resulted in the deaths of thousands of sea turtles that have washed ashore on Cumberland Island. Although shrimp nets are equipped with so-called turtle-excluder devices (TEDs), data from turtle strandings on Cumberland Island shows that TEDs have not reduced turtle deaths; in fact, turtle strandings on Cumberland Island steadily increased since the TEDs were mandated in the early 1990s. Turtle strandings have declined in recent years, likely due to the economic downturn affecting the shrimping industry.
A marine reserve adjacent to Cumberland Island would not only help safeguard sea turtle habitat, but it would also benefit the long-term health of shrimping and other fisheries in the area. Endangered right whales also give birth and raise their young in the waters near Cumberland and would greatly benefit from a marine protected area.