COSM

Life History: Georgia Sea Turtles

Seven species of sea turtles, all threated or endangered, currently inhabit the World’s oceans; only four species (listed in bold) are commonly found in the coastal waters of the Georgia Bight:

Common Name Scientific Name
Loggerhead sea turtle Caretta caretta (Linnaeus, 1758)
Leatherback sea turtle Dermochelys coriacea (Vandelli, 1761)
Kemp’s Ridley sea turtle Lepidochelys kempi (Garman, 1880)
Green sea turtle Chelonia mydas (Linnaeus, 1758)
Hawksbill sea turtle Eretmochelys imbricata (Linnaeus, 1766)
Olive Ridley sea turtle Lepidochelys olivacea (Eschscholtz, 1829)
Flatback sea turtle Natator depressus (Garman, 1880)

 

Of the four species commonly seen in Georgia marine waters, only loggerheads commonly nest on Georgia’s barrier islands. Green sea turtles occasionally nest in Georgia. Leatherback sea turtles seldom nest in Georgia and Kemp’s Ridley sea turtles seem only to be migrants through Georgia’s coastal waters.

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Nesting Loggerhead sea turtle, North Beach, involved in covering behavior, Nest [98-086].

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Nesting Leatherback sea turtle, North Beach, involved in covering behavior, [05-070]

In addition to fully marine sea turtles, the marshes and lagoons of the eastern seaboard, including Georgia, also contain another species of marine turtle, the Diamondback Terrapin, Malaclemys terrapin (Schoepff, 1793), adapted to life in brackish salt water. Diamondback Terrapins have been seen attempting to nest on road beds and behind the beaches of St. Catherines. They are small turtles, approximately eight inches across, with legs and clawed toes only slightly adapted from a terrestrial mode of life. Their nests are usually well above the storm high tide line.

The presence of Diamondback Terrapins is often deduced from their characteristic crawlway morphology. During the earlier part of this century, a Diamondback Terrapin fishery existed to provide meat for “Terrapin Soup,” a gourmet food item early in the 1900s. Diamondback Terrapins are now in a state of rapid decline, largely due to being run over during nesting or trapped in crab traps set in the marsh streams. Diamondback Terrapins are not federally listed as an endangered species, but they are listed in Rhode Island, considered a threatened species in Massachusetts, and are a “species of concern” in Georgia, Delaware, Louisiana, North Carolina, and Virginia.

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Diamondback Terrapin eggs and hatchling from dune at McQueens Inlet. Of four eggs, two hatched.

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Diamondback Terrapin female with damaged carapace after nesting on Sapelo Sound. Note crawlway to left of turtle and carapace damage.

IDENTIFICATION VIA TAXONOMIC KEY

The species of sea turtles which are encountered on the Georgia Coast include the Loggerhead Turtle (Caretta caretta), the Green Turtle (Chelonia mydas ), the Leatherback Turtle (Dermochelys coriacea), Kemps Ridley Turtle (Lepidochelys kempi), and the Hawksbill Turtle (Eretmochelys imbricata). These turtles are similar in gross morphology but can be differentiated by use of a taxonomic key (“Leave Only Bubbles“)

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Key to identification of Georgia’s sea turtles (from Stranding Form modified after Georgia DNR).

Sea Turtle Dichotomous Key

Turtle has no scutes on the carapace but has longitudinal ridges on the carapace. Leatherback Turtle

Or

Turtle has scutes arranged in a distinct patterns forming medial, lateral, and marginal positions on the carapace. Go to Step 2

 

Turtle has more than 5 medial scutes. Olive Ridley Turtle

or

Turtle has 5 medial scutes. Go to Step 3

 

The turtle has four lateral scutes. Go to Step 4

   or

The turtle has more than four lateral scutes. Go to Step 5

 

The medial scutes are imbricated and the beak is “hooked”. Hawksbill Turtle

         or

The medial scutes are not imbricated and the beak is not noticeably hooked. Go to Step 6

Along the posterior margin of the plastron there is a small terminal scute at the centerline. Kemp’s Ridley Turtle

         or

There is no terminal scute at the centerline along the posterior margin of the plastron.  Loggerhead

The posterior margin of the carapace is pointed, not rounded.  Black Turtle

         or

The posterior margin of the carapace is rounded. Go to Step 7

The lateral scutes of the carapace are noticeably larger than the medial scutes. FlatBack Turtle

         or

The lateral scutes of the carapace are nearly the same size as the medial scutes. Green Turtle

Last updated: 11/30/2015

Sea Turtle Program at St. Catherines Island • (912) 478-1744 • jgaskin@georgiasouthern.edu