Kemp’s Ridley sea Turtle

(Lepidochelys kempii)

General Characteristics

The Kemp’s ridley was named after Richard Kemp, who helped discover and carry out numerous studies on this species. Their head is moderately sized (up to 13 cm wide) with two pairs of prefrontal scales and triangular in shape. The carapace is relatively short and wide, almost circular (wider in adults than that of L. olivacea); with large, non-overlapping scutes and 5 costal scutes. Adults have a light olive-green carapace with a yellowish plastron, with distinct, small pores near the rear margins of each of the four inframarginal scutes.

Size

Kemp’s ridleys are one of the smallest sea turtles. Adults measure around 2 ft. (65 cm) in average carapace length and weigh between 70 and 100 lbs. (35-50 kg). They usually have two claws on each flipper.

Habitat

This species prefers shallow areas with sandy or muddy bottoms. Adults are largely confined to the costal areas of the Gulf of Mexico and the northwestern Atlantic Ocean, although individuals have been found as far north as Maine, U.S.A and Nova Scotia, Canada.

Diet

The Kemp’s ridley has powerful jaws that help them crush and grind their diet of crabs, clams, mussels, and shrimp. They also eat fish, sea urchins, squid and jellyfish.

Nesting

The age at which they reach sexual maturity is unknown. However, it is believed to be between 10 and 15 years, although some estimate it as high as 35 years. Unlike other sea turtles, Kemp's ridleys nest annually, usually two clutches per season, about 25 days apart. They lay an average of 110 eggs in each nest, where the eggs incubate for about 55 days. Similar to the olive ridley, they also nest in mass synchronized nestings often called “arribadas”. Their primary nesting site is located on a small beach on the northeastern coast of Mexico, near the village of Rancho Nuevo, Tamaulipas. Scattered nesting occurs on the southern and central coastline of Texas.  Many decades of intensive conservation efforts have allowed the Kemp´s ridley to establish small nesting populations in Texas.

Hatchlings

Hatchlings are small, typically measuring 43 mm (1.7 in.) in length, and are dark black in color.

Migrations

Adult female ridleys mainly migrate along the coast of the Gulf of Mexico in shallow water of less than 150 feet deep, whereas juveniles have been spotted feeding off the northeast coast of the United States, such as in Chesapeake Bay, Virginia.

Current Status

The World Conservation Union (IUCN) classifies the species as Critically Endangered - facing an extremely high risk of extinction in the wild in the immediate future. The Kemp’s ridley is often considered the most critically endangered of all sea turtle species due to the fact that it is the rarest and that over 90% of all nestings occur on only one beach, Rancho Nuevo.

Threats

The original decline was said to be brought about by egg harvesting and intentional capture of adults for meat and other products. Today, the most immediate threat is considered to be the high numbers of incidental captures by shrimp trawlers.

Population Trends

In 1947, a Mexican architect filmed an estimated 42,000 females nesting at Rancho Nuevo in one day. After that event, their numbers declined drastically.  For example, in the 1980´s they only numbered in the hundreds. It was not until recently that the ridley population began to slowly recover. This may be due primarily to strict protection efforts for nesting females and their nests and implementation of regulations requiring the use of turtle excluder devices (TED) on shrimp trawlers in the Gulf of Mexico.

Inter-American Sea Turtle Convention

Cooperative efforts from a variety of governmental as well as non-governmental organizations to conserve distinct sea turtle populations inhabiting the American Continent have existed for many years.  The Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC), which entered into force in May of 2001, provides an opportunity for dialogue and action favoring sea turtle management.  The IAC is the only international body establishing legal instruments and guidelines that commit the Parties to, among others, protect and conserve populations of sea turtles and their habitat, reduce incidental capture and foster international cooperation for research and management of sea turtles. Currently, eleven countries- Belize, Brazil, Costa Rica, Ecuador, United States, Guatemala, Netherlands Antilles, Honduras, México, Peru and Venezuela – are Signatory countries, meanwhile two more, Nicaragua and Uruguay, have sent in the necessary instruments for accession to the Government of Venezuela, the official depository nation.

Sources:

Caribbean Conservation Corporation & Sea Turtle Survival League (www.cccturtle.org)

NOAA Fisheries Office of Protected Resources (www.nmfs.noaa.gov/pr/species/turtles)

Pritchard, P.C.H. and J.A. Mortimer. 1999. Taxonomy, External Morphology, and Species Identification, p. 21-38. In: K.L. Eckert,

K.A. Bjorndal, F.A. Abreu G. and M.A. Donnelly (Editors), Research and Management Techniques for the Conservation of Sea

Turtles. IUCN/SSC Marine Turtle Specialist Group Publ. No. 4. Washington, D.C.

Wider Caribbean Sea Turtle Conservation Network (www.widecast.org)

Published by:

Pro Tempore Secretariat of the Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC), San Jose, Costa Rica, April 2005

Edited by:

Belinda Dick

English Translation:

Belinda Dick

Photo Credits:

Juvenile Kemp’s ridley - Erin E. Seney, August 2004

Kemp’s ridley with satellite transmitter - Erin E. Seney, September 2004

Illustrations:

Tom McFarland