Endangered Spotlight: Green Turtle

(Chelonia mydas)

Green Turtle. Photo: NOAA

Although they spend most of their lives in tropical and sub-tropical waters, green turtles are found all across the world.  In the Pacific, they travel as far north as Alaska and as far south as Chile and New Zealand.

Unlike most sea turtles, which spend most of their adult lives in the ocean, Pacific green turtles are known to crawl onto secluded beaches during the day to sunbathe.

Physical Description

On average, green turtles weigh between 300 and 400 pounds and reach 3 to 4 feet in length. They are the largest of all the hard-shelled sea turtles, but have a comparatively small head.  They have a short snout and paddle-like arms well adapted for swimming. 

Their shells come in various color patterns that change over time. As hatchlings, their carapace is black; then, as juveniles, it becomes more olive and brown.  As adults, the shells may be spotted or marbled with shades of black, gray, green, orange, brown and yellow.

The green turtle’s name comes from the greenish color of the turtle's fat, which is found in a layer between its inner organs and its shell.  It is greenish in color because of the turtle’s diet, which consists mainly of sea grass and algae.  Adult turtles are herbivores, but hatchlings start their lives out as omnivores, eating many jellies.

Nesting

Green turtles migrate great distances between their feeding grounds and the warm beaches from where they hatched.  Some swim distances of more than 1,500 miles (2,600 kilometers) to reach their nesting grounds.  Mature turtles will often return to the same exact beach from which they hatched.

Females will lay a clutch of a hundred-twenty or more eggs at a time, and after two months, the eggs hatch at night, and the baby turtles scuttle their way across the beach to get to the ocean. Twenty to fifty years later, they’ll be sexually mature adults, and return to their hatching grounds every two to four years to mate and lay eggs of their own.

Pacific nesting sites include secluded beaches in Mexico, Hawaii, Australia and Eastern Asia.  Florida is the largest breeding location in United States (Atlantic population).

Endangered Status

Humans have had devastating impact on green turtle populations.  Years of hunting, egg poaching, and destroying their natural beach habitat has caused a 48-65% decline in the number of mature females nesting annually over the past 100-150 years.  In addition, turtles are often caught in gillnets, trawls and traps.  Hence, they have become an endangered and protected species.

Although illegal poaching continues, green turtles are making a comeback.  Turtle-Excluding Devices, or TEDs, are one of the developments in the fishing industry to increase turtle-safe fishing methods. An increase of line fishing is another. 

Since 1989 the United States has placed an embargo on non-turtle-safe shrimp.  Mexico has an advertising campaign to dissuade the idea of turtle eggs as an aphrodisiac, with a sexy woman posing and stating her man doesn’t need turtle eggs.  And Borneo embraced and protects its hatching grounds, to help preserve its tourist trade as well as its rare reptiles.

As we continue to protect these beautiful, ancient creatures, hopefully their numbers will keep growing, and we will see more visiting our Sanctuary.