Kemp's Ridley

Kemp's Ridley
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Lepidochelys kempii
Conservation status
File:Status iucn2.3 CR.svg Critically Endangered (IUCN 2.3)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Family:	Cheloniidae
Genus:	Lepidochelys
Species:	L. kempii
Binomial name
Lepidochelys kempii (Garman, 1880)

File:Lieux pontes tortue de kemp.png

Lepidochelys kempii distribution.

Also see: Olive Ridley turtle.

Kemp's Ridley (Lepidochelys kempii) is a critically endangered species of sea turtle. It is one of two living species in the genus Lepidochelys, the other one being L. olivacea, the Olive Ridley. It is also the rarest sea turtle.

Anatomy

Kemp's Ridley is the smallest living sea turtle species, reaching maturity at 2–3 feet (61–91 cm) long and averaging only 45 kilograms (99 lb).

It is typical of a sea turtle, having a dorsoventrally depressed body with specially adapted flipper-like front limbs. Like other sea turtles, it possesses a horny beak.

Distribution

Kemp's Ridley sea turtles generally prefer warm waters but inhabit waters as far north as New Jersey, They migrate to the Gulf of Mexico, and Florida where they often inhabit the waters off Louisiana.^{[citation needed]} Their range includes the Atlantic Ocean and the Gulf of Mexico. Almost all females return each year to a single beach—Rancho Nuevo in the Mexican state of Tamaulipas—to lay eggs. Some travel as far away as the coast of Ireland.

Ecology and life history

Feeding

The Kemp's Ridley turtle feeds on molluscs, crustaceans, jellyfish, algae or seaweed, and sea urchins.

Life history

Juvenile turtles tend to live in floating sargassum seaweed beds for their first years. Then they range between Northwest Atlantic waters and the Gulf of Mexico while growing into maturity.

These turtles change color as they mature. As hatchlings they are almost entirely a dark gray-black, but mature adults have a yellow-green or white plastron and a grey-green carapace. Some say they reach sexual maturity at the age of 7-15 but others claim that maturity doesn't occur until the age of 35.^{[citation needed]}

The nesting season for these turtles is April to August. They nest mostly in the Mexican state of Tamaulipas, but sometimes on Padre Island in the U.S. state of Texas. They mate offshore. Pregnant females land in groups on beaches in what is commonly called an arribada or mass nesting. They prefer areas with dunes or, secondarily, swamps. The estimated number of nesting females in 1947 was 89,000 but shrank to an estimated 7702 by the 1985.

Females nest three times during a season, keeping 10 to 28 days between nestings. Incubation takes anywhere from 45 to 70 days. There are, on average, around 110 eggs in a clutch. The hatchlings' sex is decided by the temperature in the area during incubation. If the temperature is below 29.5 degrees Celsius the offspring will be mainly male.

Etymology and taxonomic history

These turtles are called Kemp's Ridley because Richard Kemp (of Key West) was the first to send a specimen to Samuel Garman at Harvard. However, the etymology of the name "Ridley" itself is unknown. Prior to the term being popularly used (for both species in the genus), L. kempii at least was known as the "bastard turtle".

At least one source also refers to the Kemp's Ridley as a "heartbreak turtle". In her book "The Great Ridley Rescue", Pamela Philips claimed that the name was coined by fishermen who witnessed the turtles dying after being turned turtle (on their backs). The fishermen said the turtles "died of a broken heart".

Conservation

Hunting first depleted their numbers, but today major threats include habitat loss, pollution, and entanglement in shrimping nets.

Mexico first protected Kemp's in the 1960s. In the United States, the Kemp's ridley turtle was first listed under the Endangered Species Conservation Act of 1970 on December 2, 1970, and subsequently under the Endangered Species Act (ESA) of 1973. A binational recovery plan was developed in 1984, and revised in 1992. A draft public review draft of revision number two was published by NOAA Fisheries in March 2010. This revision includes an updated threat assessment.

One mechanism that protects turtles from fishing nets is the Turtle Excluder Device (TED). Due to the fact that the biggest hit to the population of Kemp’s Ridley sea turtles is shrimp trawls, the device is attached to the shrimp trawl. It is a grid of bars with an opening at the top or bottom, fitted into the neck of the shrimp trawl. It allows small animals to slip through the bars and be caught while larger animals such as sea turtles strike the bars and are ejected thus avoiding possible drowning.

In September 2007, Corpus Christi, Texas, wildlife officials found a record of 128 Kemp's Ridley sea turtle nests on Texas beaches, including 81 on North Padre Island (Padre Island National Seashore) and 4 on Mustang Island. Wildlife officials released 10,594 Kemp's Ridley hatchlings along the Texas coast this year. The turtles are popular in Mexico, as boot material and food.

Oil spills

Some Kemp's Ridley were airlifted from Mexico after the 1979 blowout of the Ixtoc 1 rig, which spilled millions of gallons of oil into the Gulf of Mexico.

The Deepwater Horizon oil spill menaces a wide variety of marine life, from dolphins to blue crabs. Since April 30, 2010, 10 days after the accident on the Deepwater Horizon, they have recorded 156 sea turtle deaths; most of the turtles were Kemp’s ridleys. The National Oceanic and Atmospheric Administration expanded a fishing ban in the Gulf of Mexico because of the spreading oil. Louisiana Department of Wildlife and Fisheries biologists and enforcement agents have rescued Kemp's in Grand Isle .

Of the endangered marine species that frequent gulf waters, only the Kemp’s ridley relies on the region as its sole breeding ground.

BP has been accused of burning Kemps Ridley turtles alive while deliberately setting parts of the oil spill on fire. Harming or killing even one of the turtles could cause the company to receive stiff civil and criminal penalties and fines of up to $50,000.

See also

• Chelonioidea. The sea turtle superfamily.
• Caretta caretta. The loggerhead turtle.
• Chelonia mydas. The green turtle.
• Dermochelys coriacea. The leatherback turtle.
• Eretmochelys imbricata. The hawksbill turtle.
• Lepidochelys olivacea. The olive ridley turtle.
• Natator depressus. The flatback turtle.

Bibliography

• Marine Turtle Specialist Group (1996). Lepidochelys kempii. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 9 May 2006. Database entry includes a brief justification of why this species is critically endangered and the criteria used
• Sizemore, Evelyn (2002). The Turtle Lady: Ila Fox Loetscher of South Padre. Plano, Texas: Republic of Texas Press. p. 220. ISBN 1556228961. 

External links

Wikimedia Commons has media related to:

Lepidochelys kempii

• Gulf Oil Again Imperils Sea Turtle (New York Times).
• http://www.seaturtles.org
• http://www.ridleyturtles.org
• http://seamap.env.duke.edu/species/tsn/551770
• http://www.turtles.org/ridleyd.htm
• http://www.cresli.org/cresli/turtles/kemprid.html
• IUCN Red List of Threatened Species: Lepiochelys kempi
• Florida Sea Turtle information Florida Fish and Wildlife Conservation Commission Fish and Wildlife Research Institute
• http://www.tpwd.state.tx.us/publications/pwdpubs/media/pwd_bk_w7000_0013_kemps_ridley_sea_turtle.pdf