Sea Turtles & Reptiles
Kemp’s Ridley Sea Turtle
Lepidochelys kempii
ALSO KNOWN AS
Kemp’s ridley, Atlantic ridley
DISTRIBUTION
Gulf of Mexico, coastal U.S. and Nova Scotia, and parts of the Mediterranean
ECOSYSTEM/HABITAT
Coastal to open ocean
FEEDING HABITS
Foraging predator
TAXONOMY
Order Testudines (turtles, tortoises and terrapins); Family Cheloniidae (hard shelled sea turtles)
SHARE
Kemp’s ridley sea turtles are the most endangered sea turtle in the world, despite the fact that females of this species nest more often than other sea turtles. They are also the smallest species of sea turtle in the world. Their common name comes from Richard M. Kemp, a Floridian fisherman and naturalist who first submitted a Kemp’s ridley specimen to Harvard for identification in 1880. They are easily distinguishable from other sea turtles by their wide, almost circular shell or carapace and their hooked, parrot-like upper jaw.
Kemp’s ridley sea turtles are the most endangered sea turtle in the world, despite the fact that females of this species nest more often than other sea turtles. They are also the smallest species of sea turtle in the world. Their common name comes from Richard M. Kemp, a Floridian fisherman and naturalist who first submitted a Kemp’s ridley specimen to Harvard for identification in 1880. They are easily distinguishable from other sea turtles by their wide, almost circular shell or carapace and their hooked, parrot-like upper jaw.
Kemp’s ridley sea turtles are the smallest sea turtle in the world, with a maximum shell, or carapace, length of 75 centimetres. Their carapace is almost circular in shape but is slightly wider than it is long – a feature that makes them easily distinguishable from other species. They also have a hooked, parrot-like “beak” or upper jaw that differentiates them from other sea turtles found in Canada. Juveniles also have pronounced knobs running down the centre of their carapace, but these fade as the turtles age. Their carapace and body are grey-ish green on top and paler yellow on the underside.
Like all sea turtles, female Kemp’s ridleys migrate to nesting beaches every year to lay their eggs on land. Some individuals may even migrate over 1,000 kilometres between their nesting and feeding grounds. Kemp’s ridleys, like their relatives olive ridley sea turtles, are well-known for their unique nesting behaviour in which thousands of female sea turtles come together all at once to lay their eggs – a phenomenon that is called an “arribada.” Nearly 95 per cent of Kemp’s ridley nesting occurs on a single beach, Rancho Nuevo, in the state of Tamaulipas, Mexico. Nesting is usually between May and July, and females will lay up to three clutches of 90 to 110 eggs that must incubate for 50 to 60 days. Like other reptiles, the sex ratios of Kemp’s ridley offspring are determined by the incubation temperature of the nest, with cooler temperatures producing more male offspring and warmer temperatures producing more female offspring. Unfortunately, the unique nesting habits of Kemp’s ridley turtles also invite threats to the population, like natural predation and, although illegal, egg collection by humans.
After hatching from their nest and making a mad dash to the ocean, Kemp’s ridley hatchlings will spend up to 10 years perusing the open ocean before returning inshore to continue developing. Adult Kemp’s ridley turtles are typically found in nearshore waters with muddy or sandy bottoms where their preferred prey – crabs, as well as fish, jellyfish and small mollusks – are plentiful. They reach sexual maturity in their teenage years and females will often return to nest on the same beach as they were hatched.
Although there are no direct fisheries for Kemp’s ridley sea turtles, they are often caught as bycatch in fisheries – most notably trawl fisheries. In fact, in the 1990’s, up to 55,000 loggerheads and Kemp’s ridleys were killed each year in shrimp trawls. Since then, better enforcement of Turtle Excluder Devices (TEDs) in trawl nets has allowed for a slight comeback of the population, but TEDs need to be a requirement in all trawl fisheries to have a larger positive impact.
Kemp’s ridley sea turtles are the most endangered sea turtle in the world and are listed globally as Critically Endangered by the ICUN Red List of Threatened Species. In Canada, however, they have not been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) or listed under the Species at Risk Act (SARA). This is likely because they are not common in Canadian waters and are considered vagrants, only passing through from time to time.
Like other sea turtles, Kemp’s ridleys face many threats both on shore and in the ocean. The greatest threats to this species include incidental capture in fishing gear, or bycatch, egg collection (although now illegal in much of their range), plastic pollution, climate change and habitat destruction due to coastal development.