Kemp's Ridley Sea Turtles
(Lepidochelys kempii)
©Cynthia Rubio & NPS
Critically Endangered
Kemp’s Ridley turtles are one of the most seriously endangered of all sea turtles today. In 1947, a single Kemp’s Ridley arribada was calculated as having 42,000 nests. Today, the total population of females is estimated to be around 2,500. They are listed as Critically Endangered (facing an extremely high risk of extinction in the wild in the immediate future) by the International Union for Conservation of Nature and Natural Resources.
Nesting
Like its sister species the Olive Ridley, the Kemp’s Ridley utilizes the arribada (mass-nesting) as a nesting strategy. They nest more frequently than other species, every 1 ½ years and 2 to 3 times a season. They deposit around 110 eggs in their nest, which hatch in about 55 days. According to NOAA, “Kemp's ridleys are the only sea turtle species that nests predominantly during daylight hours.”
Description
The Kemp’s Ridley is the smallest of sea turtles. Adults grow to be about 2 feet long and can weigh about 100 pounds maximum. The carapace is oval and gray-green in color. The under part of the shell or plastron is yellowish-white. There are 5 costal scutes on the carapace and 4 inframarginal scutes, which join the carapace to the plastron. The head is medium sized and triangular in form. Hatchlings are black. Unlike other sea turtles whose name reflects their appearance, the Kemp’s Ridley is named after Richard M. Kemp, a fisherman in the Keys of Florida, who first submitted this species for classification.
Habitat, Range and Migration
Unlike most other turtles, the Kemp Ridley spends most if its time in shallow seas and rarely swims in waters more than 160 feet. According to NOAA, “Adult Kemp's primarily occupy neritic habitats. Neritic zones typically contain muddy or sandy bottoms where prey can be found. Their diet consists mainly of swimming crabs, but may also include fish, jellyfish, and an array of mollusks.”
The range of the Kemp’s Ridley is narrow compared to other sea turtles. Adults primarily inhabit the coastal waters off of Mexico. Their most important nesting ground is a 12-½ stretch of beach in the Mexican state of Tamaulipas. A few nest on Padre Island, off the coast of Texas and elsewhere along the Mexican gulf coast.
Hatchlings become caught up in the currents and eddies of the Gulf waters, and are re-distributed all along the Gulf and Atlantic as far north as Nova Scotia. Immature turtles can be found along the Atlantic coast as far north as Massachusetts and Canada.
Diet
Adult Kemp’s Ridleys are carnivorous bottom-feeders, eating a variety of animal foods from shallow waters. While they eat mollusks, fish, jellyfish, echinoderms etc, they have a marked preference for crabs and frequent the waters occupied by this favored delicacy.
Threats
The fact that the Kemp’s Ridley spends its sea going life in shallow coastal waters where much human sea harvesting takes place has likely contributed to its rapid historical decline. Shrimp trawls troll these shallow waters and many Kemp’s Ridley’s become the victims of incidental capture in their nets. Near shore fishing also exacts a toll.
Harvesting of eggs and slaughtering of nesting females during arribadas has also also played a significant role in bringing this animal to its current critically endangered status.
As with other sea turtles, habitat development and degradation hastens the decline of the species.
The enforced use of turtle exclusion devices by trawlers as well as the protection of nesting habitat during arribadas is required if this species is to recover from the edge of extinction.
We gratefully acknowledge the following resources:
Cynthia Rubio & NPS, photographer who gave us permission to use her Kemp’s Ridley photo from
http://www.seaturtle.org/cgi-bin/imagelib/index.pl?photo=1984
Caribbean Conservation Corporation
IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 16 December 2007
US Fish and Wildlife
World Wildlife Fund
NOAA Fisheries
WWF: Information and map of distribution:
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