A green sea turtle was spotted south of La Jolla Shores, Tuesday, May 24, feeding in the reef between The Shores and The Cove. They love to swim in warm and swallow waters, which makes La Jolla Shores a perfect place for them.
Curious to learn more about them, La Jolla Light contacted Ryan Schaeffer, lead naturalist for the only sea turtle in residence at Birch Aquarium at Scripps. He explained that green sea turtles swim the coasts of La Jolla from June to September.
“You will normally find them basking kind of higher up in the water where they can get some good sunshine. There is an eelgrass bed out there where they congregate and munch on the eelgrass,” he said.
Green sea turtles are mostly herbivores, although juveniles sometimes eat invertebrates like crabs, jellyfish or sponges. They are also, Schaeffer said, “opportunistic eaters.”
“If a green sea turtle happens to swim by a dead fish, it will take advantage of that and get a little extra nutrients out of that one,” he said.
Weighing up to 700 pounds, green turtles are among the largest sea turtles in the world. They can grow as long as 5 feet. The one spotted last week was 2-3 feet long. Schaeffer said it was probably a juvenile, about 15 years old. These turtles can live to age 100.
“If you see one, stay about 5 feet away from it,” Schaeffer explained, “because the turtle doesn’t know if you are a predator or not. The best thing to do is observe and not startle the animal. They are really fun to watch; they are really friendly as long as you’re not harassing them or getting on their nerves.”
The length of time in La Jolla waters varies with each turtle. “They will stay here for a few days — especially if they find something good to munch on. However, longer stays up to weeks have been reported to the Birch Aquarium staff,” Schaeffer said.
You can tell green sea turtles from other species because of their brown or olive shell, which is very smooth around the edges, and for their greenish skin color. Unlike their land relative, the tortoise, sea turtles are fast swimmers that can travel thousands of miles in their migrations. They use currents in their journeys, but scientists have yet to learn how sea turtles navigate the oceans.
Some of the local green sea turtles are travelers passing by, and others could be part of a larger population (around 60 individuals) that live in the San Diego South Bay, said Schaeffer. The presence of a power plant in the area heats up the water and maintains the population year-round, making it the only place on the West Coast where they are known to aggregate.
Green turtles are listed as an endangered species. Although they thrive in the South Bay, several have been killed in boat strikes, one of the many threats humans pose to this animal. Accidental catches in commercial fisheries, destruction of their habitat or entanglement in marine debris, also pose serious dangers. Green turtles are commonly hunted for their meat and their eggs.
This species has not been known to breed in La Jolla or anywhere else in San Diego. Their mating is one of the most appreciated worldwide. They lay eggs on the beach and go back to the ocean. Two months later, the eggs hatch and the newborn turtles struggle to make their way to the ocean through predators like crabs and gulls.
— Have you seen any unusual marine life in La Jolla? If so, e-mail your pictures to firstname.lastname@example.org