Kemp's Ridley Turtle
About The Species
Found primarily in the Gulf of Mexico, but also in the Atlantic Ocean as far north as Nova Scotia, Kemp’s ridley turtles are the smallest marine turtle in the world. The species is named after Richard M. Kemp, a fisherman from Key West, Florida, who first submitted the species for identification in 1906.
The Kemp's ridley is one of two species of sea turtles that engage in "arribada" nesting, where large groups of females gather offshore and come onto the beach to nest all at once. Nesting in large groups may be a defense against predators or a result of environmental factors influencing nesting. With many turtles coming ashore together and many nests subsequently hatching at the same time, it may help to reduce predation. The other species of sea turtle that nests en mass is the olive ridley.
Prior to the mid-20th century, the Kemp's ridley was abundant in the Gulf of Mexico. Historic information indicates that tens of thousands of ridleys nested near Rancho Nuevo, Mexico, during the late 1940s. An amateur video from 1947 documented an extraordinary Kemp's ridley nesting event near Rancho Nuevo. It has been estimated that approximately 42,000 Kemp's ridleys nested during that single day.
The Rancho Nuevo population experienced a devastating decline between the late 1940s and the mid-1980s. The number of nests was at a record low of 702 in 1985, representing fewer than 250 nesting females. Due to intensive conservation actions, the Kemp's ridley began to slowly rebound during the 1990s. The number of nests increased about 15 percent each year through 2009. However, in 2010 this rapid increase abruptly ended and nests remained below previous highs until 2017 when total documented nests reached near 25,000. At this time, it is unclear if future nesting will steadily and continuously increase, similar to what occurred from 1990-2009, or if nesting will continue to exhibit ups and downs as recorded in the past 5 years.
The 2015 5-year review of the Kemp's ridley sea turtle under the ESA provides additional information on abundance and population trends.
- Throughout Its Range
CITES Appendix I
- Throughout Its Range
The Kemp's ridley turtle has a triangular-shaped head with a slightly hooked beak. Hatchlings are darkly colored on both sides. Adults are generally a grayish-green color on top with a pale yellowish bottom shell. The top shell (carapace) is often as wide as it is long and contains five pairs of costal "scutes” that overlay the bony carapace. Each of the front flippers has one claw while the back flippers may have one or two.
Behavior and Diet
Sea turtles spend most of their lives in the ocean, but females leave the water to lay eggs. Air breathers, they must come to the surface regularly to breathe. Kemp’s ridleys are the only sea turtles that routinely nests during the day.
Kemp’s ridley turtles spend their first years of life primarily in deep oceanic waters of the Gulf of Mexico, where they feed on small animals and plants they find in the mats of floating algae. After recruiting to shallow coastal areas, crabs are their preferred food; however, they have been documented to also scavenge on dead fish and discarded bycatch.
Where They Live
Kemp's ridleys are distributed throughout the Gulf of Mexico and U.S. Atlantic seaboard, from Florida to New England. A few records exist for Kemp's ridleys near the Azores, waters off Morocco, and within the Mediterranean Sea and they are occasionally found in other areas around the Atlantic Basin. Adult Kemp's primarily occupy nearshore coastal (neritic) habitats which typically contain muddy or sandy bottoms where their preferred prey are found.
Depending on their breeding strategy, male Kemp's ridleys appear to occupy many different areas within the Gulf of Mexico. Some males migrate annually between feeding and breeding grounds, yet others may not migrate at all, mating with females encountered at their feeding grounds or near nesting beaches.
Female Kemp's ridleys have been tracked migrating to and from nesting beaches in Mexico and south Texas. Females leave breeding and nesting areas and migrate to foraging areas ranging from the Yucatán Peninsula to southern Florida. Some females take up residence in specific foraging grounds for months at a time and return to the same foraging grounds in subsequent years.
Ninety-five percent of worldwide Kemp’s ridley nesting occurs in in the state of Tamaulipas, Mexico. The three main nesting beaches in Tamaulipas are Rancho Nuevo, Tepehuajes, and Barra del Tordo. Nesting also occurs in Veracruz, Mexico, and in Texas, but on a much smaller scale. Occasional nesting has been documented in North Carolina, South Carolina, and Florida.
Newly emerged hatchlings inhabit a much different environment than adult turtles. After emerging from the nest, hatchlings enter the water and swim rapidly offshore. Some sea turtle species remploy an open ocean developmental stage because healthy, neonate sea turtles are rarely found in near shore waters. Some hatchlings remain in currents within the Gulf of Mexico while others may be swept out of the Gulf, around Florida, and into the Atlantic Ocean by the Gulf Stream.
Juvenile Kemp’s ridleys associate with floating Sargassum algae, using the Sargassum as an area of refuge, rest, and a place to feed. This developmental drifting period is hypothesized to last about 1-2 years or until the turtle reaches a length of about 8 inches. After this oceanic phase, Kemp’s ridleys migrate to nearshore areas of the Gulf of Mexico or northwestern Atlantic Ocean where they mature.
Lifespan & Reproduction
No one knows exactly how long Kemp’s ridleys live, but like other sea turtles, they are likely long-lived, estimates of lifespan are on the order of 30 years minimally. Scientists have estimated that Kemp’s ridleys reach sexual maturity at about 13 years of age.
Similar to olive ridleys, Kemp's ridleys display one of the most unique synchronized nesting habits in the natural world. Large groups of Kemp's ridleys gather off nesting beaches in northeastern Mexico and come ashore in large groups, called arribadas, which means "arrival" in Spanish.
There are many theories on what triggers an arribada, including offshore winds, lunar cycles, and the release of pheromones by females. However, scientists have yet to conclusively determine what triggers an arribada. Arribada nesting is a behavior found only in the genus Lepidochelys which includes the olive ridley sea turtle as well as Kemp’s ridley.
Females nest from May to July during daylight hours. They lay an average of two to three clutches per season and return to the beach to nest every 1 to 3 years. The females dig an egg chamber in the sand where they lay approximately 100 eggs, which incubate for 50 to 60 days.
Bycatch in Fishing Gear
The primary ongoing threat to Kemp's ridley sea turtles is bycatch in fishing gear. Kemp’s ridleys are primarily caught in shrimp trawls, but also in recreational fishing gear, gill nets, traps and pots, and dredges in the Gulf of Mexico and northwest Atlantic.
Harvest of Eggs
Almost the entire Kemp’s ridley sea turtle population nests along the coast of the state of Tamaulipas, on the Gulf coast of Mexico, just south of the United States-Mexico border. Historically, egg collection was an extreme threat in this area, but since nesting beaches were afforded protection in both Mexico and the United States, this threat no longer poses a major concern.
Ocean Pollution/Marine Debris
Marine turtles may die after ingesting fishing line, balloons, or plastic bags, plastic pieces, or other plastic debris which they can mistake for food. They may also become entangled in marine debris, including discarded or lost fishing gear, and can be killed or seriously injured.
In the Spotlight
In the United States, NOAA Fisheries and the U.S. Fish and Wildlife Service (U.S. FWS) have joint jurisdiction for sea turtles, with NOAA having the lead in the marine environment and U.S. FWS having the lead on the nesting beaches. Both federal agencies, along with many state agencies and international partners, have issued regulations to eliminate or reduce threats to sea turtles, while working together to recover them.
Recovery Planning and Implementation
To help identify and guide the protection, conservation, and recovery of sea turtles, the ESA requires NOAA Fisheries and U.S. FWS to develop and implement recovery plans, in close coordination with stakeholders, for each listed sea turtle species. Recovery plans provide a blueprint for conservation of the species and measurable criteria to gauge progress toward recovery.
The major recovery actions for Kemp’s ridley sea sea turtles include:
Protecting turtles on nesting beaches.
Protecting nesting and foraging habitats.
Reducing bycatch in commercial and recreational fisheries.
Reducing the effects of entanglement and ingestion of marine debris.
Working with partners internationally to protect turtles in all life-stages in foreign waters.
Supporting research and conservation projects consistent with Recovery Plan priorities.
In 1991, a recovery plan was developed to recover and protect Kemp’s ridley turtle populations in the U.S. Caribbean, Atlantic Ocean, and Gulf of Mexico. A bi-national recovery plan for Kemp’s ridleys was later developed in conjunction with the the Secretary of Environment and Natural Resources, Mexico (SEMARNAT). The final bi-national plan was published in 2011. The recovery team has since made additional recommendations have been.
The highly migratory behavior of sea turtles makes them shared resources among many nations, so conservation efforts for sea turtle populations in one country may be jeopardized by activities in another. This means that protecting sea turtles on U.S. nesting beaches and in U.S. waters alone is not enough to ensure the continued existence of the species. Learn more about international conservation efforts below.
NOAA Fisheries is working to minimize effects from human activities that are detrimental to the recovery of Kemp’s ridley turtle populations in the U.S. and internationally. Together with our partners, we undertake numerous activities to support the goals of the Kemp’s ridley turtle recovery plans, with the ultimate goal to delist the species.
Efforts to conserve Kemp’s ridley turtles include:
Rescue, disentanglement, and rehabilitation.
Eliminating the collection of turtles and their eggs.
Eliminating the harassment of turtles on nesting beaches through education and enforcement.
When NOAA Fisheries lists a species under the ESA, we must determine whether there are areas of habitat that are essential, or contain features that are essential, for the conservation of the species. Those areas may be designated as "critical habitat." A critical habitat designation does not set up a marine preserve or refuge. Critical habitat protections only apply when federal funding, permits, or projects are involved.
In 2010, NOAA Fisheries and the U.S. FWS were jointly petitioned to designate critical habitat pursuant to the discretion that exists for the agency to determine whether to designate critical habitat for species listed prior to 1978.
To reduce the incidental capture of sea turtles in commercial fisheries, we have enacted regulations to reduce bycatch in certain U.S. commercial fishing gears (gillnets, longlines, pound nets, and trawls) that have known, significant bycatch of sea turtles. Measures include:
Changes to fishing practices.
In the Gulf of Mexico, NOAA Fisheries has worked closely with the shrimp trawl fishing industry to develop turtle excluder devices (TEDs) to reduce the mortality of sea turtles incidentally captured in shrimp trawl gear.
Since 1989, the U.S. has prohibited the importation of shrimp harvested in a manner that adversely affects sea turtles. The import ban does not apply to nations that have adopted sea turtle protection programs comparable to that of the U.S. (i.e., require and enforce the use of TEDs) or to nations where bycatch in shrimp fisheries does not present a threat to sea turtles (for example, nations that fish for shrimp in areas where sea turtles do not occur). The U.S. Department of State is the principal agency of this law, while we serve as technical advisor. We provide extensive TED training throughout the world.
We are also involved in cooperative gear research projects designed to reduce sea turtle bycatch in the Gulf of Mexico and Atlantic pelagic longline fisheries, the Hawaii-based deep set longline fishery, the Atlantic sea scallop dredge fishery, the Chesapeake Bay pound net fishery, and non-shrimp trawl fisheries in the Atlantic and Gulf.
Bycatch in fishing gear is the primary anthropogenic source of sea turtle injury and mortality in U.S. waters. The most effective way to learn about sea turtle-fishery interactions is to place observers aboard fishing vessels. Under the ESA, NOAA Fisheries identifies commercial and/or recreational fisheries in the Atlantic Ocean, Gulf of Mexico, and Pacific Ocean that are required to have observers to record sea turtle interactions. The purpose of observing these fisheries is to:
Learn more about sea turtle interactions.
Evaluate measures to reduce fisheries impacts/bycatch of protected sea turtles.
Determine whether additional measures may be necessary to prevent sea turtle bycatch.
NOAA Fisheries determines which fisheries are required to carry observers to monitor potential interactions with sea turtles through an annual determination. Observers may also be placed on fisheries through our authorities under the Magnuson-Stevens Act.
Sea Turtle Stranding and Response
A stranded sea turtle is one that is found on land or in the water dead, injured, sick, or exhibiting usual behavior. One of the most well-known examples of mass strandings is when cold-stunned sea turtles strand during winter months on the Atlantic and Gulf coasts. During these events, thousands of turtles may require care.
The Sea Turtle Stranding and Salvage Network was established in response to the need to better understand the threats sea turtles face in the marine environment, to provide aid to stranded sea turtles, and to salvage dead sea turtles that may be useful for scientific and educational purposes. The network collects information on and documents strandings of marine turtles along the U.S. Gulf of Mexico and Atlantic coasts and includes federal, state, and private partners. This information is compiled into a centralized database.
NOAA’s Pacific Islands Fisheries Science Center’s Marine Turtle Biology and Assessment Program rehabilitates and studies stranded sea turtles throughout the Hawaiian Islands. Other state and local organizations respond to sea turtle strandings on the U.S. West Coast.
The actions taken by stranding network participants improve the survivability of sick, injured, and entangled turtles while also helping scientists and managers to expand their knowledge about diseases and other threats that affect sea turtles in the marine environment and on land.
The conservation and recovery of sea turtles requires international cooperation and agreements to ensure the survival of these highly migratory animals. We have a broad national and international program and work closely with partners under two international environmental agreements that deal exclusively with sea turtle conservation:
Additional international treaties and agreements include:
Convention on International Trade in Endangered Species (CITES): Listed in Appendix I, which prohibits international trade of wild flora and fauna.
Cartagena Convention: Protected under Annex II of the Specially Protected Areas and Wildlife (SPAW) Protocol.
The Mexican government has played a vital role in the conservation of the Kemp's ridley sea turtle. The Kemp's ridley has benefited from legal protection by Mexico since the 1960s. In 1977, a refuge was established at the only known nesting beach and included the Rancho Nuevo nesting beach as part of a system of reserves for sea turtles. In 1990, a complete ban on taking any species of sea turtle was implemented by the Mexican government. In 2002, the beach at Rancho Nuevo was designated as a Natural Protected Area under the category of Sanctuary.
Key Actions and Documents
- Receipt of revised application and request for comments (84 FR 51116)
- Receipt of application (82 FR 43224)
- Revised permit application (pdf, 66 pages)
- Draft Environmental Assessment (pdf, 22 pages)
- Permit application (pdf, 99 pages)
- Issuance of permit
- Notice of availability (environmental assessment)
- Receipt of application
- Receipt of application
- Permit (PDF, 17 pages)
- Environmental assessment (PDF, 108 pages)
- Permit application (PDF, 154 pages)
NOAA Fisheries conducts various research activities on the biology, behavior, and ecology of the Kemp’s ridley sea turtle. The results of this research are used to inform management decisions and enhance recovery efforts for the endangered Kemp’s ridley.
Turtle population assessments include information on abundance and distribution, life history and human impacts. This information allows us to evaluate and determine the effectiveness of conservation and recovery measures, and to adjust management plans as needed. Sea turtle assessments are done through a number of ways. To obtain population counts, researchers conduct systematic aerial surveys of selected areas and use data from nesting sites as well as stranding and fisheries bycatch data (number of dead sea turtles) to ultimately estimate the population size. Surveys are supplemented with studies on population structure (genetic analysis), foraging and reproductive behavior, movement and distribution by age class (hatchling, juveniles, sub-adults, adults) and habitat through tagging and tracking work.
Tagging and Tracking Studies
Satellite telemetry allows researchers to track sea turtles as they swim from place to place. These satellite tags do not harm the turtles in any way and are designed to eventually fall off. The data will tell us where important feeding areas are, help us understand migration patterns, and anticipate where turtles may come in contact with fisheries and their gear.
Fishing Gear Research
We engage in the development, evaluation, and modifications of fishing gear to promote sea turtle conservation while at the same time retaining a sustainable fisheries catch. This work includes TED development, use of circle hooks in longline fisheries, time and area closures for gillnets, and modifications to pound net leaders.
Learn more about our fishing gear research. [link to Fishing Gear Research subpage]
Sea Turtle Genetics
NOAA Fisheries’ National Sea Turtle Molecular Genetics Center serves as a worldwide central depository for sea turtle tissue and DNA samples and constitutes a major area of research supporting sea turtle conservation. For example, a turtle’s unique genetic “fingerprint” can be used to determine its nesting population and home nesting beach.
Programmatic biological opinion on the Gulf of Mexico oil and Gas Program in Federal waters.
Integrated Bayesian models to estimate bycatch of sea turtles in the Gulf of Mexico and southeastern U.S. Atlantic coast shrimp otter trawl fishery
Elizabeth A. Babcock, Michael Barnette, James Bohnsack, John Jeffery Isely, Clay Porch, Paul M…
Data & Maps
Tracks the implementation of recovery actions from Endangered Species Act (ESA) recovery plans.