Green Sea Turtle (Chelonia mydas)
- Texas Status
- U.S. Status
- Threatened, Listed 7/28/1970
- Protection Status Notes
- The Green sea turtle is currently designated as Endangered in the breeding colony populations in Florida and on the Pacific coast of Mexico. It is designated Threatened throughout the remainder of its range.
- Green sea turtles have a yellowish green body with dark spots on their head and flippers. Their shell is dark brown or olive colored and up to 55 inches long. Green sea turtles can grow to weigh 850 pounds.
- Life History
- Green sea turtles range throughout the Atlantic, Pacific, and Indian Oceans primarily in the tropical regions. During the day, green sea turtles feed in the seagrass beds that grow in shallow waters. At night, they sleep on the shallow bottom and sometimes out of the water on rocky ledges. Although sea turtles are subject to predation throughout their life cycle, predation is particularly high during the first two years of life. The eggs are eaten by raccoons, skunks, opossums, mongooses, coatis, and dogs. Hatchlings are preyed upon by mammals, sea birds, crabs, and carnivorous fishes. Predation continues to be high until the turtles are big enough to avoid being swallowed. Sharks are a formidable predator throughout the life cycle of the green sea turtle.
Their diet consists of mostly seagrasses and algae, with small amounts of animal foods such as sponges, crustaceans, sea urchins, and molluscs. The turtles migrate from nesting areas to feeding grounds, which are sometimes several thousand miles away. Most turtles migrate along the coasts, but some populations are known to migrate across the ocean from nesting area to feeding grounds. As a species that migrates long distances, these turtles face special problems associated with differing attitudes toward conservation in different countries.
Green sea turtles can live from 30 - 50 years. Adults reach sexual maturity between 8 and 13 years of age. Adults mate every 2 to 3 years during the nesting season just off the nesting beaches. Nesting occurs in numerous places in the tropics, including the beaches of the Gulf of Mexico, the Caribbean and Florida, Bermuda and the Cayman Islands. The turtles nest from March to October, with greatest activity along Gulf of Mexico beaches between June and August.
The females may nest several times during a season, laying as many as 145 soft, round white eggs per nest. The eggs incubate in the sand for 48 to 70 days. The incubation period is longer when the weather is cool. Hatchlings emerge from the nest mostly at night, race quickly to the surf and swim hurriedly toward the open ocean. The color of the hatchlings, black above and white below, is probably an adaptation to life near the surface in the open ocean, making them less conspicuous to fish and bird predators.
- Green sea turtles feed in shallow water areas with abundant seagrasses or algae. The major nesting beaches are always found in places where the seawater temperature is greater than 77 degrees Fahrenheit.
- In Texas, green sea turtles are found in the Gulf of Mexico. They occasionally visit the Texas coast.
- The meat and eggs of the green sea turtle have long been a source of food for people. Although international trade of wild green sea turtles is against the law, capturing turtles for local consumption still persists in many central Pacific Islands, Southeast Asia and Indonesia, Indian Ocean islands, east coasts of Africa and Arabian peninsula, in Central and South America, and in Mexico. Exploitation of the nesting grounds either by human interference or pollution poses the greatest threat to these turtles. In the past, green sea turtles were often killed in large shrimp trawl nets. Today, turtle excluder devices (TED's) pulled by shrimp boats help reduce mortality from net entanglement.