Of the seven living species of marine turtles, five ply the waters off the Atlantic and Gulf coasts of the United States.
Distribution: Bahamas, Cuba, The Dominican Republic and the east coast of the U.S. as far north as NJ and south through the Florida Keys and the Gulf of Mexico
Attributes: Average length of 38 inches and can weigh from 200 to 400 pounds
Diet: Crabs, mollusks, shrimp and jellyfish as well as encrusting animals that attach themselves to rocks and reefs
The Loggerhead turtle, so named because of its unusually large head, plies the temperate and tropical waters of the Bahamas, Cuba, The Dominican Republic and the east coast of the U.S. as far north as NJ and south through the Florida Keys and the Gulf of Mexico. It is truly diverse in its choice of habitat, abiding in coastal waters and streams as well as the open ocean. Caretta caretta, as it is called in scientific circles, has an average length of 38 inches and can weigh from 200 to 400 pounds. It attains these large proportions on a diet of crabs, mollusks, shrimp and jellyfish as well as encrusting animals that attach themselves to rocks and reefs. In order to feed on these hard to crack critters, the Loggerhead has a powerful jaw. It is further distinguished by its reddish brown shell comprised of five pairs of costal and vertebral scutes as well as three pairs of inframarginal scutes. Additionally, this species has claws on its fore-flippers: two each.
The Loggerhead is classified as a threatened, rather than endangered, species. In the eastern Gulf of Mexico, it numbers over 3000 strong with other populations in other areas of the world. However, the future of this, like all other sea turtles, is still in question. Continuing efforts to protect this delicate species have yielded positive results. Unfortunately, many Loggerheads are still lost to shrimp trawls and habitat loss.
As the most common of the sea turtles along Florida’s coast, the Loggerhead receives special attention in this state, particularly during nesting season. In the months of early Spring, the ocean wanderers gather off the coast in large numbers to mate. From May to August, under cover of night, the females labor to shore to deposit their precious cargoes.
Distribution: Atlantic and Indo-Pacific Oceans, The Gulf of Mexico and the Mediterranean Sea
Attributes: About 3 and-a-half feet long and 300 pounds
Diet: As juveniles: shellfish, jellyfish and other marine creatures. As adults: sea grasses and algae
Chelonia mydas, the green turtle, derives its common name from the color of its green fat. It can be further distinguished from other species by its size and weight: about 3 and-a-half feet long and 300 pounds. It bears a pair of scales at the front of its head and its gray-green carapace has four costal scutes, none of which overlap. A close look at the fore-flippers will reveal one claw on each.
The green turtle makes its home in the waters of the Atlantic and Indo-Pacific Oceans, the Gulf of Mexico and the Mediterranean Sea. Its preferred habitat is the shallow, well-vegetated waters near coasts and islands. This is so because the green turtle, and its close relative the black turtle, are the only herbivorous sea turtles. As juveniles, they subsist on a diet of shellfish, jellyfish and other marine creatures. However, upon reaching adulthood, they dine on the variety of sea grasses and algae that their marine home offers. They prefer the choicest leaves: those that are young and higher in protein content. This habitat also affords these marine reptiles shelter. They can be found resting under rock ledges and coral overhangs.
Like the other sea turtle species, the green turtle nests during the summer months. From June through September, the females use their superior navigational abilities to make their way to high energy beaches in the Caribbean, although some nest in Florida.
This turtle, like so many of its marine relatives, is listed as endangered. Its numbers have decreased because of egg-poaching and, in particular, due to the harvesting of adults. The fat of the green turtle and its calipee, a gelatin-like cartilage, are used to make turtle soup, a much-sought-after delicacy in some countries.
Another burden the green turtle shoulders is the tumor-like growths called fibropapillomas. This affliction, believed to be viral in nature, strikes near body openings such as the eyes and mouth. The growths can kill by obstructing the vision of the turtle or by closing off its mouth, eventually causing starvation.
The population size of the green turtle is unknown and scientists are unsure if the population continues to dwindle or if its numbers have grown in recent years.
Distribution: All the major oceans in both tropical and subtropical waters
Attributes: Between 31 and 36 inches long and 100 to 120 pounds
Diet: Sponges, tunicates, mollusks and sea urchins
The Hawksbill is arguably the most beautiful of all the marine turtles however, relatively little is known about it. Belonging to the genus species Eretmochelys imbricata, the hawksbill is distinguished by the overlapping, sharp scutes on the edges of its shell. It has four pairs of these intercostal scutes and a particularly narrow jaw, from which it gets its name. The shell of the adult is a dark, greenish-brown color while the juveniles have the famed “tortoiseshell” pattern, an amber color with wavering streaks of yellow, red or brown. If you look closely at its front flippers, you will see two claws on each.
The hawksbill is one of the smaller species of turtle. The average adult is between 31 and 36 inches long and weighs 100 to 120 pounds. It’s habitat, however, is anything but small. It can be found in all the major oceans in both tropical and subtropical waters. They are often spotted by divers in the Florida keys, though more infrequently now than in past years. The hawksbill favors rocks and coral ledges in relatively shallow water. Here, it finds its favorite repast, sponges. This unusual dietary choice is a puzzle to biologists since the sponges the Hawksbill feeds on are primarily composed of glass-like, silicate needles. There seems to be no nutritional value in these sponges, and yet the Hawksbills thrive on them. They have also been seen consuming tunicates, mollusks and sea urchins.
Unlike some other species of turtle, the Hawksbill does not nest in large groups. Rather, the females come to shore singly and use a variety of beaches to deposit their clutches. As one of the more agile of the sea turtles, the Hawksbill can climb over land obstructions that would prove impassable to other species, giving it a larger choice in selecting a nesting site.
Unfortunately for the Hawksbill, its beauty has been its bane. The striking shells have long been sought after for the jewelry and other ornaments that can be produced from them and the meat of the turtle is considered a delicacy in some countries. Consequently, the Hawksbill has been grossly overhunted and has earned the unfortunate title of “endangered species.”
Distribution: Open waters of the Gulf of Mexico and along the Gulf Coast of Mexico, Texas, Louisiana and Florida
Attributes: Average shell length of 26 to 27 inches and weighs in at between 80 and 100 pounds
Diet: Primarily blue crabs as well as mollusks, shrimp and jellyfish
The Kemps Ridley or Lepidochelys kempi is the smallest of the ocean-going turtles. Its circular shell measures only 26 to 27 inches in length and the animal itself weighs in at between 80 and 100 pounds. The Kemps Ridley can be recognized by the color of its shell: grayish-brown on the juveniles and olive green on the adults. The shell is further distinguished by five pairs of costal plates and 3 or 4 inframarginal scutes. Each of these inframarginal scutes has one pore near the back edge.
The Kemps Ridley can be found in the open waters of the Gulf of Mexico and along the Gulf Coasts of Mexico, Texas, Louisiana and Florida. Younger turtles are distributed in U.S. coastal waters from Texas to Maine. During the colder winter months, those turtles in the north head for the warmer waters of Florida and the Gulf of Mexico.
During its watery travels, the Kemps Ridley dines on its favorite food: blue crabs. When this delicacy is unavailable it makes do with mollusks, shrimp and even jellyfish.
The Kemps Ridley bears the unfortunate distinction of being the most endangered of all the sea turtles. A film shot in 1947 by Andres Herrera showed approximately 40,000 nesting females. These mass nestings called arribadas, Spanish for “arrivals,” occur during daylight hours between April and June of every year. The female Ridleys, heavy with their burden of eggs, wait in the coastal waters just off this stretch of beach in the western Gulf of Mexico until strong onshore winds and a high surf make possible their journey to shore. Because of intense poaching of nests and the taking of gravid females as well as continuing loss of life due to drowning in shrimp trawls, pollution and the alteration of the turtles’ habitat, the numbers of this delicate species have been severely reduced. It is estimated that the number of nesting females in current arribadas is between 400 and 500, just 1 percent of the total 50 years ago. The estimated total population of Kemps Ridleys is between 1300 and 1500 individuals. These low numbers have changed the nature of the arribadas. The turtles now approach in several, small groups rather than en masse. The reduced sized of the nesting groups makes the clutches more susceptible to scavenging, further reducing the number of surviving individuals.
The precarious state of the Kemps Ridley has led to massive conservation efforts. Thanks to the steadfast leadership of Archie Carr and other biologists and conservationists, this species is being given another chance. However, like so many endangered species, their future is far from secure.
Distribution: Most widely distributed of the sea turtles, occurring in both pelagic and coastal ocean waters around the globe
Attributes: Average length of eight-and-a-half feet and a weight in excess of 2000 pounds
Diet: Primarily jellyfish as well as squid and marine fauna
Shaped for speed and built for strength, the Leatherback turtle, Dermochelys coriacea, is a swift behemoth. It is a species of superlatives. Attaining an average length of eight-and-a-half feet and a weight in excess of 2000 pounds, the Leatherback is by far the largest of the ocean-going turtles and indeed is the largest of all living reptiles. It is the deepest diver, reaching depths of 3000 feet. Only the elephant seal and sperm whale can boast an equal claim. In order to withstand the intense pressure at these depths, it is likely that the Leatherback’s chest collapses, a feat made possible by its lack of a rigid breastbone. Additionally, this gentle giant swims the furthest North and South, traveling as much as 3000 miles from its nesting sites and withstanding low temperatures that would stun and kill other reptilian species. It can do so since it has the ability to regulate its body temperature, a skill unique to this marine reptile. Perhaps not surprisingly, the Leatherback is the most widely distributed of the sea turtles, occurring in both pelagic and coastal ocean waters around the globe.
Besides its daunting size, the Leatherback is easily identified from its carapace. Unlike its close relatives, the Leatherback lacks a rigid, outer shell and instead has a smooth, leather-like skin in which are embedded thousands of tiny bones in an intricate mosaic. This leathery suit has seven raised ridges, adding to the streamlined design of the Leatherback’s body. This characteristic, combined with powerful, clawless limbs, makes it a formidable and swift swimmer. The mostly white plastron, which has five ridges similar to the seven on the carapace, breaks an otherwise even color pattern. The remainder of the Leatherback is a dark black-brown with a scattering of white and yellow markings.
Ironically, the largest of all reptiles feeds on jellyfish, animals that are composed primarily of water. Understandably, the Leatherback eat a lot of jellyfish. Juveniles may eat twice their weight in the watery creatures every day. These turtles have also been observed to eat squid and other marine fauna, as well, but these are secondary to its favorite diet. In order to assist the consumption of jellyfish, the Leatherback has a specialized mouth, full of backward pointing spines that prevent their meals from flowing back into the sea.
From March through August, the females gather along steeply sloping beaches leading into deep water. Common sites are along the coasts of Indonesia, new Guinea, Central America, the Guianas and the southern Pacific Coast of Mexico. Very rare is the Leatherback that nests along Florida’s shores. These conditions minimize the turtles’ actual time on land, a necessity considering the massive bulk of the streamlined creatures. Both singly and in large groups, the 70,000 to 115,000 remaining mother turtles drag their ponderous bulks to shore.
Although less a commodity to turtle harvesters than other species, the Leatherback population has declined due to egg poaching and pollution. Too often, plastic bags are mistaken for jellyfish, and the result is usually death. Like most other species of marine turtles, the Leatherback is endangered.