Juvenile green sea turtle feeding on seagrass bed (Credit: Oceana)
The presence of sea turtles is vital to our marine ecosystem. For more than 100 million years, they have helped maintain the health of the ocean and even benefit animal and plant life on our beaches. As ocean health declines due to pollution from plastics and other debris, sea turtles continue to support these interconnected ecosystems.
For example, green sea turtles—vegetarians—graze on seagrass beds on the ocean floor, preventing them from becoming overgrown. In South Carolina, sea turtle researchers have found that juvenile green turtles are feeding on a non-native Pacific seaweed, Gracillaria vermiculophylla. This may be why the young turtles are thriving here. Ten of the 15 stranded turtles observed this year have been juvenile greens. Without green turtles eating seagrass and this invasive seaweed, currents could become obstructed, and slime mold, algae and fungus could overtake areas, harming fish that people eat.
Hawksbill sea turtles, which are not found in South Carolina, use their long, pointy beaks to eat sponges from coral reef crevices. This helps maintain reef health by creating open space for corals to colonize.
Leatherback sea turtles—large, black turtles that grow up to seven feet long—pass by our shores each spring after nesting farther south in the Atlantic. They consume hundreds of pounds of jellyfish daily. Without them, jellyfish populations could spiral out of control.
Our state reptile, the loggerhead turtle, is named for its massive jaws supported by powerful muscles that crush the shells of blue crabs, lobsters, horseshoe crabs and other crustaceans. As loggerheads move along the ocean floor, they create paths that aerate and compact the seafloor, benefiting many other species by providing feeding opportunities. Loggerheads also feed on jellyfish.
What about sea turtle eggs? While turtle lovers may not like to think about it, these eggs provide food for other animals. As of mid-July, more than 151,000 eggs have been laid in South Carolina, with more still to come. Most of these eggs will not produce adult turtles, but they will help sustain other land-dwelling species. Leatherbacks feed on jellyfish as far north as the Arctic Circle and then lay eggs in the Caribbean, nourishing other creatures there as well.
The contributions sea turtles make to both ocean and beach ecosystems are essential to maintaining the natural balance of our environment.
Nesting Update (as of July 16):
Isle of Palms: 27 nests and 14 false crawls (Includes green sea turtle tracks in Wild Dunes on July 9)
Sullivan’s Island: 8 nests and 8 false crawls