Kemp's Ridley Sea Turtle
Status: Critically Endangered
The Kemp's ridley is the smallest of the eight species of sea turtles. Adults range from 75-100 pounds (34-45 kilograms). In 1880 a Florida fisherman and naturalist named Richard M. Kemp found the first documented specimen of this turtle. To honor his finding the species name became Lepidochelys kempii.
The hatchlings of this species are a solid grey black color. As they begin to grow into juveniles the coloration of the plastron (bottom shell) turns to white. The adults are broadly oval or heart shaped and their shells are olive to gray green. The skin color ranges from creamy color to white. The plastron is a creamy or yellow green in color.
The preferred habitat for the Kemp’s is shallow coastal areas, bays and lagoons. While in these areas they often seek their favorite food, crabs. One consequence of this habitat choice is that entanglement with fishing nets, hooks and other marine debris is quite common.
The nesting season for the Kemp’s is from April – August of each year. The nesting range is from Galveston, Texas to Tamaulipas, Mexico. The average clutch size is 100 eggs. This species lays the smallest eggs of the sea turtles. The eggs of all sea turtles are perfectly round in shape and have a leathery shell. The Kemp’s eggs are about the size of a ping pong ball. Nesting females will on average lay 2-3 clutches per season. The incubation period ranges from 48 to 62 days, depending on air temperature. The temperature within the nest will affect the sex ratio of the nest. Incubation temperatures below 29.5 degrees Celsius (85 degrees Fahrenheit) tend to produce male offspring. Therefore, lower spring incubation temperatures would tend to produce a large proportion of male babies.
The Kemp's is the only sea turtle which routinely nests in the daytime. Gale force winds usually precede nesting aggregations which are called "arribadas" in Spanish. The largest recorded nesting "arribada" was captured in a film from 1947 at Rancho Nuevo beach in Tamaulipas, Mexico. In this film it was approximated that 40,000 turtles came ashore to nest. Today such large aggregations do not occur due to the near extinction of this species. From the 1940’s-70’s poaching of the nesting turtles and their eggs decimated the population. The Kemp’s ridley received federal protection in 1977 under the CITES Act. Due to continued efforts by the Mexican and Texas goverments the Kemp’s is now on the road to recovery. _________________________________________________________________________________
In 2011, a large arribada occured at Rancho Nuevo, Tamaulipas, Mexico (The main nesting beach for this species). It was estimated that during a 2-day time period up to 7,000 Kemp's ridleys came ashore to lay their eggs. Below is a link to photos from this and other stunning "arribada". All photos were taken by the biological team of Rancho Nuevo.
Distribution of the Kemp's ridley
Nearly the entire nesting population comes ashore near the community of Rancho Nuevo, Tamaulipas, Mexico. Occasionally females nest on the Texas Coast and farther south in the Mexican state of Veracruz. Juveniles are encountered in bays and estuaries as far north as Louisiana and other Gulf states on both sides of the border. Rare specimens have been found as far north as Cape Cod, Massachusetts. However, the majority of the population feeds and nests in the Gulf of Mexico and adults are generally restricted to the Gulf of Mexico. There is not a clear consensus as to whether or not large nesting aggregations of Kemp's ridleys historically occurred on the Texas Coast.
Current Threats and Historic Reasons for Decline
Large scaled exploitation of eggs and meat at the main nesting beach occurred from the 1940's-1960's. In the early 1970's the Mexican and Texas goverments joined forces to protect the remaining stock. Current threats include incidental drowning from entanglement and poor fishing practices. Future threats could be the development of key nesting beaches for the Kemp's ridley.
Photos By: Adrienne McCracken