GREEN SEA TURTLE

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Guy LaBranche, La. Dept. of Wildlife &
Fisheries

Chelonia mydas

Federal Status: Threatened (July 28, 1978)
State Status: Threatened (December 20, 1989)

Description: The common name of this species refers to the color of the body fat not the general coloration of the shell, which is brownish, sometimes shaded with olive. Carapace often marked with radiating, mottled pattern. Field marks to look for are 4 costal scutes, the first one not touching the nuchal, and 1 pair of prefrontal scales. The length of the shell in adults is usually 0.9-1.2 m (2.9-3.9 ft) but may be greater than 1.4 m (4.5 ft). Adults weigh between 113 kg and 204 kg (249-450 lb) with 1 recorded over 295 kg (650 lb). Preferred habitats include shallow water bays, estuaries, and shoals containing an abundance of submerged aquatic vegetation. Females nest every 2 to 4 years and may lay several hundred eggs during a given breeding season. This species is unique among sea turtles in that it is mostly herbivorous, i. e., its diet consists mostly of plant material. However, hatchlings and yearlings are primarily carnivorous and adults occasionally eat marine animals, especially jellyfish.

Habitat: Warm bays and oceans, seagrass beds, estuaries; mainland beaches and islands (nesting). Nest throughout tropical and subtropical regions as far north as Florida; there are no nesting records for Louisiana. May have once numbered in excess of 50 million individuals; now estimated at 100,000-400,000 adults.

Distribution: Found throughout the warmer waters of the world. In Louisiana, this species is relatively rare, with most sightings from the eastern coast.

Reasons for decline: Green turtles were once one of the most abundant sea turtles, but they are also considered the most palatable and have been heavily exploited for food. Harvest of eggs and females on nests, and adults and subadults from foraging areas has been primarily responsible for the decline. This species was once harvested commercially from sea grass beds around the Chandeleur Islands of southeastern Louisiana. Erosion of barrier islands and other factors which decrease available seagrass beds, as well as incidental capture have also contributed to the decline. While commercial harvesting has been eliminated in the United States, it continues to be a serious threat in some areas. Development of beachfront property, which threatens nesting areas, contributes also to the decline in the population.

March 2004

Conservation efforts: Many nesting beaches are given full protection from development and other human disturbances. Shrimpers are now required to use turtle exclusion devices (TEDs) to reduce unintentional drownings in trawls.