Atlantic Green Sea Turtle

Adult Atlantic green sea turtles have a smooth, oval-shaped carapace, or upper shell, that lacks keels or raised ridges. Their carapace contains four pairs of lateral scutes, while the plastron, or lower shell, has four inframarginal scutes that join the upper and lower shells. These inframarginal scutes do not contain pores. Shell coloration can range from pale to dark brown, olive green, or bluish-black, often marked with brown patterns. Both the front and rear flippers have a single claw. Males and females are generally similar in size, although males can be identified by their longer, thicker tails.

Range

The green turtle is found along the North American coastline from Massachusetts southward to Mexico, as well as from British Columbia to California. Important nesting sites occur in Mexico, Costa Rica, Guyana, Suriname, and Ares Island off Dominica in the West Indies. Within the United States, smaller nesting groups are found along the eastern coast of Florida.

Reproduction

Male and female green turtles migrate toward nesting grounds together and mate in offshore waters. At night, females come ashore and dig nests on beaches with relatively steep slopes. A female can produce as many as seven clutches during a single nesting season. Each clutch generally contains between 75 and 200 eggs, while incubation lasts approximately 48 to 70 days depending on local beach and water conditions.

Green turtles generally become sexually mature between four and six years of age in tropical environments, while maturity may take five to thirteen years in temperate regions. Females do not necessarily nest every year and may return to nesting beaches at intervals of two, three, or four years.

Reasons for Decline

Green turtles have historically been heavily exploited while nesting because of demand for turtle products and meat. Their cartilage was also once processed for use in turtle soup. This exploitation caused many nesting populations to disappear completely. Where populations have already been reduced, heavy predation on eggs and young hatchlings has contributed to further declines.

The development and intensive use of coastal areas have also reduced the amount of quiet, undisturbed beach habitat available for nesting. Human activity along shorelines continues to limit suitable nesting locations.

Boat propellers are another serious threat because collisions can cause severe injuries and death. Commercial fishing and shrimping operations can cause turtles to drown, suffer severe injuries, or become trapped and tangled in fishing nets. Fortunately, federal regulations now require shrimp trawlers operating in the Gulf of Mexico and Atlantic Ocean to use turtle excluder devices, or TEDs, throughout the year.

Marine debris creates additional dangers. Plastic bags, food wrappers, helium balloons, and monofilament fishing line that enter the ocean can kill sea turtles as well as other marine animals. Floating balloons and plastic bags can look similar to jellyfish, which are sometimes consumed by Atlantic green turtles. When turtles accidentally swallow plastic or fishing line, these materials can block their digestive tracts and eventually result in death.

History in Connecticut

To date, no Atlantic green turtle has been documented along the Connecticut shoreline. However, the species may occasionally pass through Connecticut waters during the warmer months as part of its seasonal movements.

Interesting Facts

Green turtles are believed to be capable of navigating with remarkable precision, traveling as far as 1,400 miles between feeding grounds and nesting beaches. Their navigation appears to involve an orientation system based partly on the sun and a compass-like sense, somewhat comparable to the navigation abilities observed in bees.

Despite their name, green turtles are primarily herbivorous as adults. Their main food is turtlegrass, which grows in the shallow tropical waters where these turtles feed.

Protective Legislation

At the federal level, Atlantic green turtles are protected under the Endangered Species Act of 1973 and are listed in Appendix I of CITES, the Convention on International Trade in Endangered Species. In Connecticut, they are also protected under Connecticut General Statutes Section 26-311.

What You Can Do

People can help protect sea turtles by avoiding illegal turtle products, including turtle leather and tortoise-shell goods. Properly disposing of or recycling plastic bags, fishing line, and balloons can also reduce the amount of dangerous debris entering marine environments.

To address the problem of balloons entering Long Island Sound, Connecticut has enacted legislation restricting helium balloon releases to no more than nine balloons within a 24-hour period. Because wind can carry balloons considerable distances, balloons released even in inland areas of Connecticut can eventually reach the Sound.