Kemp's ridley sea turtle

Kemp's ridley sea turtle
U.S. Fish and Wildlife Service Southeast Region · CC BY 2.0 · source
Name	Kemp's ridley sea turtle
Status	CR
Status system	IUCN3.1
Genus	Lepidochelys
Species	kempii
Authority	(Garman, 1880)

Kemp's ridley sea turtle is a critically endangered species of sea turtle, renowned for its unique synchronized nesting behavior known as an *arribada*. It is the smallest and most endangered sea turtle, primarily inhabiting the Gulf of Mexico. The species faces severe threats from human activities, particularly bycatch in commercial fisheries, leading to intensive international conservation efforts.

Taxonomy and Evolution

The species was first described by the American zoologist Samuel Garman in 1880. It is one of two extant species in the genus *Lepidochelys*, its closest relative being the olive ridley sea turtle. Genetic studies suggest the two species diverged from a common ancestor relatively recently in the Miocene epoch. The genus name *Lepidochelys* is derived from Ancient Greek, while the specific epithet honors Richard M. Kemp, a Florida fisherman who submitted the type specimen to Harvard University. Its evolutionary history is closely tied to the warm coastal waters of the Atlantic Ocean.

Physical Characteristics

It is the smallest of all sea turtles, with adults typically measuring around 60 to 70 centimeters in carapace length and weighing between 35 and 45 kilograms. The carapace is nearly circular and olive-gray in color, while the plastron is a pale yellowish-white. Hatchlings are darkly colored, almost black, with flippers edged in white. Like other sea turtles, it possesses powerful, paddle-like flippers adapted for swimming in open ocean currents. The species exhibits slight sexual dimorphism, with mature males having longer, thicker tails and more curved claws than females.

Habitat and Distribution

This turtle has a remarkably restricted range compared to other marine turtles. Its major nesting beaches are concentrated primarily on the eastern coast of Mexico, especially at Rancho Nuevo in the state of Tamaulipas. Foraging grounds are found in shallow, coastal waters of the Gulf of Mexico and along the Atlantic coast of the United States, with juveniles commonly found in areas like the Chesapeake Bay and Long Island Sound. They prefer soft-bottomed habitats such as seagrass beds and estuaries, which provide abundant food resources.

Behavior and Diet

The species is best known for its unique mass nesting behavior, where thousands of females emerge simultaneously on a single beach in an *arribada*, a spectacle primarily observed at Rancho Nuevo. They are primarily diurnal feeders, with a diet consisting mostly of crustaceans, particularly crabs. They also consume jellyfish, mollusks, sea urchins, and fish. Juveniles in estuaries often forage along the bottom, using their strong jaws to crush prey. Their migratory patterns are influenced by water temperature and prey availability, often following currents like the Gulf Stream.

Conservation Status

Listed as Critically Endangered on the IUCN Red List, it is considered the world's most endangered sea turtle. The primary threat is incidental capture in shrimp trawling nets, a problem addressed by the mandatory use of Turtle Excluder Devices in U.S. and Mexican waters. Other significant threats include coastal development destroying nesting habitats, pollution (especially plastic debris), climate change affecting sand temperatures, and historical egg harvesting. Major conservation programs are led by agencies like the U.S. Fish and Wildlife Service and NOAA Fisheries, alongside international agreements like the Inter-American Convention for the Protection and Conservation of Sea Turtles.

Reproduction and Development

Females reach sexual maturity at approximately 10 to 15 years of age. They exhibit strong natal homing, returning to nest on or near the same beach where they hatched. Nesting occurs primarily from April to July, with females laying about 100 eggs per clutch and may nest up to three times in a season. The incubation period lasts roughly 45 to 60 days, with hatchling sex determined by incubation temperature—a process known as temperature-dependent sex determination. After emerging, hatchlings undertake a frenzied dash to the sea, orienting toward the brightest horizon, often threatened by artificial lighting from nearby developments like South Padre Island.

Category:Sea turtles Category:Fauna of the Gulf of Mexico Category:Critically endangered biota of North America