Overview
Brief Summary
Description
Trusted
Biology
Trusted
Comprehensive Description
Description
Trusted
Distribution
Kemp's Ridley Turtle is found mainly in the Gulf of Mexico. This species breeds in large nesting aggregations. At Rancho Nuevo, the primary nesting beach for this species in Tamaulipas, Mexico, 42,000 females came ashore to nest on a single day in 1947. By 1989, the number of females nesting on this beach had dropped to 545. Intensive conservation efforts in subsequent decades have been at least somewhat successful: the number of nesting females at Rancho Nuevo was well in excess of 2000 by 2003, with the population apparently continuing on a positive trajectory, and the total number of adult females present in the Gulf of Mexico was estimated to be around 5,000 in 2004. Adults are most often seen off southwestern Florida, much less commonly in the western Gulf. Juveniles range much more widely, to the eastern, western, and north Atlantic Ocean. Nearly all Kemp's Ridley nesting for the world population occurs at Rancho Nuevo, Tamaulipas, Mexico, but nesting has also been reported from beaches in Vera Cruz, Tabasco, and Campeche (Mexico); Colombia; Brevard, Lee, Palm Beach, Pinellas, Sarasota, and Volusia Counties in Florida (U.S.A.); Georgia (U.S.A.); and South Carolina (U.S.A.). Active efforts to establish nesting at several sites in south Texas (U.S.A.) have been successful. Hatchlings apparently spend the first two years of life drifting around the Gulf of Mexico in floating patches of Sargassum Weed (Ernst and Lovich 2009 and references therein).
Trusted
Geographic Range
Kemp’s Ridleys (Lepidochelys kempii) can be found from Nova Scotia and Newfoundland to Bermuda. Nesting Ridleys are found mainly in the Gulf of Mexico. In migration, they follow two major routes: one heads north to the Mississippi coastline and the second extends southward to the shores of the Yucatan Peninsula at the Campeche Bank.
Biogeographic Regions: nearctic (Native ); neotropical (Native ); atlantic ocean (Native )
- Wilkinson, T. 2003. The riddle of ridley's.. National Parks, 77: 26-29.
- Ernst, C., R. Barbour. 1972. Turtles of the United States. Lexington, Kentucky: The University Press of Kentucky.
- U.S. National Park Service, 2003. "Kemp's ridley nesting." (On-line). National Parks (Padre Island National Seashore). Accessed August 04, 2006 at http://www.nps.gov/pais/website/kemp's_ridley.htm.
Trusted
-
UNESCO-IOC Register of Marine Organisms
http://www.marinespecies.org/aphia.php?p=sourcedetails&id=1318
-
Müller, Y. (2004). Faune et flore du littoral du Nord, du Pas-de-Calais et de la Belgique: inventaire. [Coastal fauna and flora of the Nord, Pas-de-Calais and Belgium: inventory]. Commission Régionale de Biologie Région Nord Pas-de-Calais: France. 307 pp.
http://www.marinespecies.org/aphia.php?p=sourcedetails&id=9269
-
North-West Atlantic Ocean species (NWARMS)
http://www.marinespecies.org/aphia.php?p=sourcedetails&id=2901
-
Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Biodiversity. Texas A&M Press, College Station, Texas.
http://www.marinespecies.org/porifera/porifera.php?p=sourcedetails&id=145245
-
van der Land, J. (2001). Tetrapoda, in: Costello, M.J. et al. (Ed.) (2001). European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels, 50: pp. 375-376
http://www.marinespecies.org/aphia.php?p=sourcedetails&id=1406
-
MEDIN (2011). UK checklist of marine species derived from the applications Marine Recorder and UNICORN, version 1.0.
http://www.marinespecies.org/asteroidea/aphia.php?p=sourcedetails&id=149081
-
Borges, P.A.V., Costa, A., Cunha, R., Gabriel, R., Gonçalves, V., Martins, A.F., Melo, I., Parente, M., Raposeiro, P., Rodrigues, P., Santos, R.S., Silva, L., Vieira, P. & Vieira, V. (Eds.) (2010). A list of the terrestrial and marine biota from the Azores. Princípia, Oeiras, 432 pp.
http://www.marinespecies.org/ascidiacea/aphia.php?p=sourcedetails&id=149079
-
Ramos, M. (ed.). 2010. IBERFAUNA. The Iberian Fauna Databank
http://www.marinespecies.org/aphia.php?p=sourcedetails&id=149024
Trusted
-
North-West Atlantic Ocean species (NWARMS)
http://www.marinespecies.org/aphia.php?p=sourcedetails&id=2901
Trusted
National Distribution
United States
Origin: Native
Regularity: Regularly occurring
Currently: Present
Confidence: Confident
Type of Residency: Non-breeding
Trusted
Global Range: Adults essentially are restricted to the Gulf of Mexico. Immatures inhabit the Gulf and also the U.S. Atlantic coast north to Long Island Sound (Morreale et al. 1992), New England, and Nova Scotia. Occasional individuals reach Bermuda, the Azores, and European waters (see USFWS 1992, 1998). Important foraging areas include Campeche Bay, Mexico, and Louisiana coastal waters (Ogren 1992). Cold-stunned juveniles frequently appear in late fall/early winter on beaches on northern Long Island, New York (e.g., see Burke et al. 1991, Morreale et al. 1992). Live ridleys occur in Chesapeake Bay mainly from May through November (Mitchell 1991).
There is a single major nesting beach, at Rancho Nuevo, Tamaulipas, Mexico; 60 percent of nesting occurs along a 40-kilometer stretch of beach there (NMFS and USFWS 2007). In 2006, eggs were deposited in several hundred nests near Tampico, Mexico, and in about 100 nests in Texas (NMFS and USFWS 2007). Sporadic nesting has occurred as far north as North Carolina and south to Colombia (Palmatier 1993).
Trusted
Distribution: Carribean Sea, Atlantic Ocean (EC/NE/NW/WC), occasionally on the coasts of France, Spain, England (incl. Channel islands: Jersey), Italy, Portugal Africa: Mauritania, Americas: SE Mexico (Yucatan) Colombia [Castro,F. (pers. comm.)], USA and Canada (chiefly gulf of Mexico: Texas, Louisiana, Mississippi, Alabama, Atlantic coast as far north as New England and Nova Scotia: Florida, Georgia, South Carolina, North Carolina, Virginia, Maryland, Delaware, New Jersey, Connecticut, Massachusetts, New Hampshire, Maine)
Type locality: restricted to Key West, Florida (by SMITH & TAYLOR 1950).
Trusted
Tropical and temperate seas in Atlantic Basin, incl. Gulf of Mexico
Trusted
Range
Trusted
Physical Description
Morphology
Physical Description
Lepidochelys kempii is the smallest species of sea turtle, measuring from 55 to 75 cm in length. Average length is 65 cm. Individuals weigh between 30 and 50 kg. The head and limbs (flippers) are non-retractile. The shell is streamlined, making this turtle extremely hyrdrodynamic. The carapace is a gray-olive color, whereas the plastron is an off-white to light yellow color.
Lepidochelys kempii has four limbs; two foreflippers and two hindflippers. The foreflippers power the turtle through the water while the hindflippers are used to steer and stabilize the turtle in the water. One to two claws are present on each foreflipper.
Ridleys have an upper eyelid for eye protection. As turtles, they lack teeth, and the jaw has a broad-beak shape. The external features of males and females do not differ until they reach maturity. Males are characterized by longer, thicker tails, and may have larger curved foreflippers.
Range mass: 30 to 50 kg.
Range length: 55 to 75 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes shaped differently
Trusted
Size
Diagnostic Description
This species differs from the loggerhead in smaller size, lack of a reddish-brown dorsum, presence of an interanal scute, and presence of pored scutes on the bridge. It differs from the hawksbill and green turtles in having the first costal in contact with the nuchal. It differs from the Pacific ridley in having usually five costals on each side of the carapace rather than usually six or more.
Trusted
Ecology
Habitat
Habitat and Ecology
Systems
- Terrestrial
- Marine
Trusted
Lepidochelys kempii mainly stays near shallow coastal regions characterized by bays and lagoons. These turtles prefer waters that have sandy or muddy bottoms, but also may take to the open seas. At sea, this species has the ability to dive to great depths.
This species is rarely seen on shore, but it is not uncommon to see L. kempii floating in the water just offshore. Females come on shore to nest.
Habitat Regions: tropical ; saltwater or marine
Aquatic Biomes: coastal
Trusted
-
UNESCO-IOC Register of Marine Organisms
http://www.marinespecies.org/aphia.php?p=sourcedetails&id=1318
Trusted
Water temperature and chemistry ranges based on 332 samples.
Environmental ranges
Depth range (m): 0 - 2100
Temperature range (°C): 3.547 - 27.461
Nitrate (umol/L): 0.071 - 19.394
Salinity (PPS): 32.282 - 36.898
Oxygen (ml/l): 3.098 - 6.764
Phosphate (umol/l): 0.038 - 1.293
Silicate (umol/l): 0.756 - 18.598
Graphical representation
Depth range (m): 0 - 2100
Temperature range (°C): 3.547 - 27.461
Nitrate (umol/L): 0.071 - 19.394
Salinity (PPS): 32.282 - 36.898
Oxygen (ml/l): 3.098 - 6.764
Phosphate (umol/l): 0.038 - 1.293
Silicate (umol/l): 0.756 - 18.598
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
Trusted
Comments: Habitat of adults primarily includes shallow coastal and estuarine waters, often over sandy or muddy bottoms where crab are numerous. Most adults stay in the Gulf of Mexico, and they are rare along the Atlantic coast of the northeastern United States. Apparently most activity is benthic. Post-hatchlings spend 1-4 years as surface pelagic drifters in weedlines of offshore currents in the Gulf of Mexico and Atlantic Ocean, then shift to benthic coastal habitats of various types, especially where crabs and other invertebrates are numerous (CSTC 1990, NMFS and USFWS 2007).
Nesting occurs on well-defined elevated dune areas, especially on beaches backed up by large swamps or bodies of open water having seasonal, narrow ocean connections.
Trusted
Trusted
Trusted
Migration
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Most individuals move north or south from the major nesting beach at Rancho Nuevo and then settle in resident feeding areas for several months or more in various coastal locations in the Gulf of Mexico (see NMFS and USFWS 2007). An unknown percentage of the population migrates migrates up to thousands of kilometers between nesting beaches and Atlantic coastal feeding areas as far north as Long Island Sound, New York (Morreale et al. 1992; Morreale and Standora, no date), and beyond.
Trusted
Trophic Strategy
Food Habits
Lepidochelys kempii feeds on floating crabs, mollusks, shrimp, jellyfish and some vegetation. The jaws of these turtles are shaped for crushing and grinding.
Animal Foods: mollusks; aquatic crustaceans; cnidarians
Plant Foods: algae; macroalgae
Primary Diet: omnivore
Trusted
Comments: Adults evidently are primarily benthic feeders that specialize on crabs; juveniles feed on sargassum, mollusks often associated with sargassum, and fishes and shrimps probably discarded by anglers (Shaver 1991). Spider crabs and rock crabs were important prey at Long Island, New York, where ridleys also consumed lady crabs, blue mussels, bay scallops, mud snails, marine plants, and debris (Burke et al. 1994; Copeia 1993:1176-1180). Recorded stomach contents also include shrimp, sea urchins, sea stars, and fishes.
Trusted
Associations
Ecosystem Roles
Sea turtles have no significant economic role. Eggs and turtles were harvested in the past for reasons outlined under "Predation", but the harvesting of turtles or their eggs is now illegal.
Trusted
Predation
Lepidochelys kempii is most vulnerable as a hatchling crawling from the nest to the shore. The slow-moving hatchlings make easy targets for herons, dogs, raccoons, and a variety of seabirds. The primary predatory threat to adults comes from sharks, especially the tiger sharks. Killer whales have also been known to consume sea turtles.
Human interference with nesting behavior may facilitate predation, and act as a barrier to this species. Lights around nesting areas confuses hatchlings about which way to crawl, sometimes causing them to crawl away from the water. Trash and noise can cause females to turn around from the nesting beach and back into the water, preventing deposition of eggs. The turtles are also hunted illegally to harvest meat. The shells can be made into combs and eyeglass frames. Eggs are also illegally collected because it is believed they have an aphrodisiac effect.
Known Predators:
- tiger sharks ( Galeocerdo cuvier)
- herons
- seabirds
- killer whales (Orcinus orca)
- humans (Homo sapiens)
- raccoons (Procyon lotor)
Trusted
Population Biology
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 1 - 5
Comments: Despite occurrence of this species throughout the Gulf of Mexico and in much of the northern Atlantic, there remains only a single important nesting area.
Trusted
Global Abundance
10,000 - 100,000 individuals
Comments: Total number of nests for all beaches in Mexico in 2006 was estimated at 12,143, with another 100 in the United States (mainly Texas) (NMFS and USFWS 2007). This equates to more than 4,000 females. Given a nesting interval of about 2 years or a little less, the total number of adult females in 2006 was approximately 7,000-8,000.
In 2007, more than 4,000 females nested during a 3-day period at Rancho Nuevo.
Trusted
General Ecology
Predation on eggs (especially by coyote), hatchlings, and nesting adults sometimes has resulted in high mortality rates. Human predation on eggs and nesting adults formerly was an important mortality source; presently, drowning of adults in commercial fishing gear is more important. Egg survivorship (to hatching) was 0.59 in one study (see Iverson 1991).
Trusted
Life History and Behavior
Behavior
Communication and Perception
It is not known to what extent sea turtles communicate with one another. They make grunting noises which can be heard by other turtles, and apparently use these vocalizations to locate each other. Visual cues are probably important in identifying other members of their species, and some tactile communication undoubtedly occurs during mating. However, the bulk of communication in this species remains undescribed.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; magnetic
- Scholastic, Inc., 2001. "Meet Dr. Frank Paladino" (On-line). Ocean Life. Accessed November 13, 2005 at http://teacher.scholastic.com/activities/explorer/oceanlife/main.asp?template=meet_explorer&article=interview_frank.
- Scholastic, Inc., 1998. "Meet Dr. Richard Reina" (On-line). Ocean Life. Accessed November 13, 2005 at http://teacher.scholastic.com/activities/explorer/oceanlife/main.asp?template=meet_explorer&article=interview_reina.
Trusted
Cyclicity
Comments: In northern estuaries, diving activity peaked at dusk and dawn (see Morreale and Standora, no date).
Trusted
Life Cycle
Development
Eggs are deposited on shore and incubate for an average of 55 days. Embryo development is temperature dependent. Lower nest temperatures tend to produce more males, whereas higher temperatures tend to produce more females.
Hatchlings uses a caruncle (temporary tooth) to break open the egg. After a hatchling escapes from the egg, it may take 3 to 7 days to crawl to the surface of the beach. Hatchlings emerge from the sand at night and immediately crawl towards the water. To locate the sea, hatchlings apparently orient themselves toward the greater light intensity reflected off the water. There may also be an internal magnetic compass that directs them to the water. After an individual hatchling enters the water, it goes into a “swim frenzy” for 24 to 48 hours. The hatchling swims into deeper water that protects it from predators.
The first year of life is spent away from shore. This year is dubbed the “lost year” because individuals in this age class are rarely seen near costal regions.
Lepidochelys kempii takes 11 to 35 years to reach maturity.
Development - Life Cycle: temperature sex determination
Trusted
Life Expectancy
Lifespan/Longevity
Mortality for L. kempii is very high around the time of hatching. For individuals reaching adulthood, lifespan generally ranges from 30 to 50 years.
Typical lifespan
Status: wild: 30 to 50 years.
Trusted
Lifespan, longevity, and ageing
Trusted
Reproduction
Individuals of this species spend most of their lives in isolation, generally coming into contact with conspecifics only to mate and to nest.
Mating takes place in the water. Males use their long curved flippers and claws to grip a female during mating.
Females swim to shore in a congregation called a “arribada,” then nest on beaches near the Texas-Mexico border (Tamaulipas Mexico, Padre Island National Seashore). A female uses her foreflippers to dig a body pit which is deep enough for her carapace to be level with the surrounding sand. She then uses her hindflippers to dig the cavity into which the eggs will be deposited. After the eggs are deposited, the female fills in the egg cavity and body pit with her hindflippers and uses her plastron to erase markings of the nest.
The eggs are leathery and covered in mucus which protects them from breaking as they are laid. Females may spend two or more hours nesting.
Mating System: polygynandrous (promiscuous)
Females nest every two to three years, and may lay between one and nine clutches per nesting season. Females lay between 50 and 200 eggs per clutch. The nesting season extends from April to July.
Both males and females are reported to reach sexual maturity between the ages of 11 and 35 years.
Breeding interval: Females breed every two or three years, but can lay multiple clutches within a single breeding season.
Breeding season: The breeding season is from April to July.
Range number of offspring: 50 to 200.
Average gestation period: 55 days.
Range age at sexual or reproductive maturity (female): 11 to 35 years.
Range age at sexual or reproductive maturity (male): 11 to 35 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
Average gestation period: 60 days.
Average number of offspring: 110.
Females invest energy in the production of eggs and the digging of the nest. However, after providing their eggs with some protection by burying them, females expend no further energy or effort in caring for their young. Young are independent from the time of hatching.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female)
- Wilkinson, T. 2003. The riddle of ridley's.. National Parks, 77: 26-29.
- U.S. National Park Service, 2003. "Kemp's ridley nesting." (On-line). National Parks (Padre Island National Seashore). Accessed August 04, 2006 at http://www.nps.gov/pais/website/kemp's_ridley.htm.
Trusted
Individual adult females lay usually 3 clutches averaging about 95-100 eggs at intervals of 10-28 days, during daylight from April to July. Individual females nest at intervals of 1-4 years (most often 2 years). Large numbers of females may nest simultaneously on one beach. Eggs hatch in 45-58 days (see NMFS and USFWS 2007). Available information indicates that females begin nesting at an estimated age of 10-17 years (see NMFS and USFWS 2007). As is true of all sea turtles, this species has temperature-dependent sex determination.
Trusted
Molecular Biology and Genetics
Molecular Biology
Barcode data: Lepidochelys kempii
There is 1 barcode sequence available from BOLD and GenBank. Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen. Other sequences that do not yet meet barcode criteria may also be available.
-- end --
Download FASTA File
Trusted
Statistics of barcoding coverage: Lepidochelys kempii
Public Records: 1
Specimens with Barcodes: 6
Species With Barcodes: 1
Trusted
Conservation
Conservation Status
IUCN Red List Assessment
Red List Category
Red List Criteria
Version
Year Assessed
- Needs updating
Assessor/s
Reviewer/s
Contributor/s
Justification
History
- 1994Endangered(Groombridge 1994)
- 1990Endangered(IUCN 1990)
- 1988Endangered(IUCN Conservation Monitoring Centre 1988)
- 1986Endangered(IUCN Conservation Monitoring Centre 1986)
- 1982Endangered
Trusted
Lepidochelys kempii is currently listed as endangered by the United States Fish and Wildlife Service and IUCN.
US Federal List: endangered
CITES: no special status
IUCN Red List of Threatened Species: critically endangered
Trusted
National NatureServe Conservation Status
United States
Rounded National Status Rank: N1N - Critically Imperiled
Trusted
NatureServe Conservation Status
Rounded Global Status Rank: G1 - Critically Imperiled
Reasons: Range centered in Gulf of Mexico; only one major nesting area, along Gulf Coast of Tamaulipas, Mexico; population includes 7,000-8,000 adult females and is increasing; major threats include degradation of beach and coastal marine/estuarine habitats and mortality in commercial fisheries; vulnerable to oil spills.
Intrinsic Vulnerability: Highly vulnerable
Environmental Specificity: Very narrow to narrow.
Trusted
Status: Endangered
Date Listed: 12/02/1970
Lead Region: Southwest Region (Region 2)
Where Listed:
Population detail:
Population location: entire
Listing status: E
For most current information and documents related to the conservation status and management of Lepidochelys kempii , see its USFWS Species Profile
Trusted
Status
Trusted
Trends
Global Short Term Trend: Decline of 50-70%
Comments: Annual number of nests at Rancho Nuevo increased significantly after the 1980s, from fewer than 1,000 to more than 4,000 by 2002 and 7,866 in 2006 (see NMFS and USFWS 2007).
Despite the recent increase, the trend over the past three generations (75 years, assuming average age of nesting female is 25 years) is a major decline (probably declined more than 90 percent).
Global Long Term Trend: Decline of >90%
Comments: Number of nesting females declined from possibly more than 42,000 in a single arribada in the 1940s to only around 234 (740 nests) by the mid-1980s to 7,000-8,000 in 2006 (NMFS and USFWS 2007). However, the 1940s population may have been an order of magnitude smaller (see NMFS and USFWS 2007).
Trusted
Trusted
Threats
Degree of Threat: A : Very threatened throughout its range communities directly exploited or their composition and structure irreversibly threatened by man-made forces, including exotic species
Comments: A major decline occurred with heavy harvest of eggs (and adults) prior to the mid-1960s, but now all main nesting areas have good protection. Present significant threats: beach and coastal development in areas away from the main nesting beach; various forms of coastal marine habitat degradation (e.g., bottom trawling and dredging of inshore and nearshore areas); mortality in shrimp nets and other fishing gear (this threat has been reduced to some degree through improved regulations); boat collisions; oil spills and exposure to other contaminants; and entanglement in and ingestion of marine debris (especially plastics) (Thompson 1990; CSTC 1990; USFWS 1992, 1998; NMFS and USFWS 2007). Threats to the main nesting beach in Mexico are presently few, but other areas in Mexico where nesting occurs are experiencing continued human population growth and increasing development pressure (USFWS 1992, 1998). Concentration of nesting in one area makes the species vulnerable to detrimental impacts of severe storms. The species' tendency to congregate in large numbers at breeding times increases vulnerability to disturbance. Climate change is a potential threats (could alter sex ratios; sea level rise and increased storm frequency could reduce nesting habitat).
Trusted
Trusted
Management
Management Requirements: The recovery plan (USFWS 1992) summarizes management needs. Frazer (1992) emphasized the primary need for clean and productive marine and coastal environments; installation of turtle excluder devices in shrimp trawl nets and use of low pressure sodium lighting on beaches were suggested as appropriate sea turtle conservation technologies, whereas headstarting, captive breeding, and hatcheries were regarded as ineffective at best. Captive breeding was not regarded as a preferred management tool by CSTC (1990). See also Bjorndal (1982).
Reduction in trawl-related mortality, through the use of turtle excluder devices and seasonal fisheries closures and/or reduced tow times by shrimp trawlers, is regarded as a primary management need (Mitchell 1991, NMFS 1993, Lewison et al. 2003).
All nesting areas should be protected throughout the reproductive season (through hatchling emergence).
Trusted
Global Protection: None to few (0-3) occurrences appropriately protected and managed
Comments: Most important nesting areas are adequately protected. Coastal feeding areas and migration corridors have some degree of protection through improved fishing regulations.
Needs: This species is in need of continued protective fishing regulations (e.g., use of Turtle Excluder Devices, restriction of tow times, fishing closures) in the Gulf of Mexico and southeastern U.S. Atlantic coast. Increased protection of Rancho Nuevo beach should be funded. Strict standards and limitations on any potentially polluting activity, including disposal of plastics at sea, should be insituted. Lagoonal/estuarine feeding habitats need protection. Sronger limitations on outer continental shelf drilling and oil tanker design and traffic should be imposed. Designated critical habitat should be expanded.
See recovery plan (USFWS 1992, 1998).
Trusted
Conservation
Trusted
Relevance to Humans and Ecosystems
Benefits
Economic Importance for Humans: Negative
There is no known direct economic importance for humans.
Trusted
Economic Importance for Humans: Positive
As a result of illegal harvesting, sea turtle meat may be eaten, and shells be made into combs or eyeglass frames. The eggs of L. kempii are believed to have an aphrodisiac effect.
Positive Impacts: food ; body parts are source of valuable material; source of medicine or drug
Trusted
Economic Uses
Comments: Eggs formerly were heavily exploited.
Trusted
Wikipedia
Kemp's ridley sea turtle
Kemp's ridley sea turtle[1] (Lepidochelys kempii), or Atlantic ridley sea turtle is the rarest sea turtle and is critically endangered. It is one of two living species in the genus Lepidochelys (the other one being L. olivacea, the olive ridley sea turtle).
Contents |
Anatomy [edit]
Kemp's ridley is a small sea turtle species, reaching maturity at 60–90 cm (24–35 in) long and averaging only 45 kg (99 lb). Typical of sea turtles, it has a dorsoventrally depressed body with specially adapted flipper-like front limbs and a beak. The Kemp's ridley turtle is the smallest of the sea turtles, with adults reaching about 2 feet in length and weighing up to 100 pounds. The adult Kemp's ridley has an oval carapace that is almost as wide as it is long and is usually olive-gray in color. The carapace has five pairs of costal scutes. In each bridge adjoining the plastron to the carapace, there are four inframarginal scutes, each of which is perforated by a pore. The head has two pairs of prefrontal scales. Hatchlings are black on both sides. The Kemp's ridley has a triangular-shaped head with a somewhat hooked beak with large crushing surfaces. This turtle is a shallow water benthic feeder with a diet consisting primarily of crabs.
Distribution [edit]
Kemp's ridley sea turtles generally prefer warm waters but inhabit waters as far north as New Jersey, They migrate to the Gulf of Mexico, and Florida where they often inhabit the waters off Louisiana.[citation needed]
Their range includes the Atlantic Ocean and the Gulf of Mexico. Almost all females return each year to a single beach—Rancho Nuevo in the Mexican state of Tamaulipas—to lay eggs. Some travel as far away as the coast of Ireland.
Feeding and life history [edit]
Feeding [edit]
The Kemp's ridley turtle feeds on mollusks, crustaceans, jellyfish, fish, algae or seaweed, and sea urchins.
Life history [edit]
Juvenile turtles tend to live in floating sargassum seaweed beds for their first years.[2] Then they range between northwest Atlantic waters and the Gulf of Mexico while growing into maturity.
These turtles change color as they mature. As hatchlings, they are almost entirely a dark gray-black, but mature adults have a yellow-green or white plastron and a grey-green carapace. They reach sexual maturity at the age of 12-13.[citation needed]
The nesting season for these turtles is April to August. They nest mostly in the Mexican state of Tamaulipas, but sometimes on Padre Island in the US state of Texas. They mate offshore. Gravid females land in groups on beaches in what is commonly called an arribada[2] or mass nesting. They prefer areas with dunes or, secondarily, swamps. The estimated number of nesting females in 1947 was 89,000, but shrank to an estimated 7702 by 1985.[3]
Females nest three times during a season, keeping 10 to 28 days between nestings. Incubation takes 45 to 70 days. There are, on average, around 110 eggs in a clutch. The hatchlings' sex is decided by the temperature in the area during incubation. If the temperature is below 29.5°C, the offspring will be mainly male.
Etymology and taxonomic history [edit]
These turtles are called Kemp's ridley because Richard Kemp (of Key West) was the first to send a specimen to Samuel Garman at Harvard. However, the etymology of the name "ridley" itself is unknown. Prior to the term being popularly used (for both species in the genus), L. kempii at least was known as the "turtle".[4]
At least one source also refers to the Kemp's ridley as a "heartbreak turtle". In her book The Great Ridley Rescue, Pamela Philips claimed the name was coined by fishermen who witnessed the turtles dying after being "turned turtle" (on their backs). The fishermen said the turtles "died of a broken heart".[5][6]
Conservation [edit]
Hunting first depleted their numbers, but today major threats include habitat loss, pollution, and entanglement in shrimping nets.
Mexico first protected Kemp's ridleys in the 1960s. In the United States, the Kemp's ridley turtle was first listed under the Endangered Species Conservation Act of 1970[7] on December 2, 1970, and subsequently under the Endangered Species Act (ESA) of 1973. A binational recovery plan was developed in 1984, and revised in 1992. A draft public review draft of the second revision was published by NOAA Fisheries in March 2010.[8] This revision includes an updated threat assessment.[9]
One mechanism used to protect turtles from fishing nets is the turtle excluder device (TED). Because the biggest danger to the population of Kemp’s ridley sea turtles is shrimp trawls, the device is attached to the shrimp trawl. It is a grid of bars with an opening at the top or bottom, fitted into the neck of the shrimp trawl. It allows small animals to slip through the bars and be caught while larger animals, such as sea turtles, strike the bars and are ejected, thus avoiding possible drowning.
In September 2007, Corpus Christi, Texas, wildlife officials found a record of 128 Kemp's ridley sea turtle nests on Texas beaches, including 81 on North Padre Island (Padre Island National Seashore) and four on Mustang Island. Wildlife officials released 10,594 Kemp's ridley hatchlings along the Texas coast that year. The turtles are popular in Mexico, as boot material and food.[10]
Oil spills [edit]
Some Kemp's ridleys were airlifted from Mexico after the 1979 blowout of the Ixtoc 1 rig, which spilled millions of gallons of oil into the Gulf of Mexico.
The Deepwater Horizon oil spill menaces a wide variety of marine life, from dolphins to blue crabs. Since April 30, 2010, 10 days after the accident on the Deepwater Horizon, 156 sea turtle deaths were recorded; most were Kemp’s ridleys. The National Oceanic and Atmospheric Administration expanded a fishing ban in the Gulf of Mexico because of the spreading oil. Louisiana Department of Wildlife and Fisheries biologists and enforcement agents have rescued Kemp's ridleys in Grand Isle.[11]
Of the endangered marine species frequenting Gulf waters, only the Kemp’s ridley relies on the region as its sole breeding ground.[12]
As part of the effort to save the species from some of the devastating effects of the Deepwater Horizon oil spill, scientists have begun taking eggs from their nests and incubating them elsewhere. Sixty-seven eggs were collected from a nest along the Florida Panhandle on June 26, 2010, and brought to a temperature-controlled warehouse at NASA’s Kennedy Space Center, but only 56 hatched. State and federal officials plan to bring thousands more eggs for incubation in the coming months.
The overall plan is to collect some 70,000 eggs from sea turtle nests on beaches across Alabama and Florida before they hatch and swim out into the oil from the Deepwater Horizon rig explosion off Louisiana.[13]
See also [edit]
- Loggerhead sea turtle
- Green sea turtle
- Leatherback sea turtle
- Hawksbill sea turtle
- Olive ridley sea turtle
- Flatback sea turtle
References [edit]
- ^ Turtles of the World: Annotated Checklist of Taxonomy and Synonymy, December 2010, page 000.94
- ^ a b "Kemp's Ridley Turtle (Lepidochelys kempii) - Office of Protected Resources - NOAA Fisheries". NOAA Fisheries. Retrieved 2009-05-11.
- ^ http://www.nps.gov/pais/naturescience/strp.htm
- ^ Dundee, Harold A. (2001). "The Etymological Riddle of the Ridley Sea Turtle". Marine Turtle Newsletter 58: 10–12. Retrieved 2008-12-30.
- ^ "Frequently Asked Questions". Help Endangered Animals - Ridley Turtles. Gulf Office of the Sea Turtle Restoration Project. Retrieved 2009-01-05.[dead link]
- ^ Philips, Pamela (September 1988). The Great Ridley Rescue. Mountain Press. p. 180. ISBN 0-87842-229-3.
- ^ http://www.nmfs.noaa.gov/pr/laws/esa/
- ^ Draft Kemp's Ridley Recovery Plan, 2010
- ^ 2010 Threats Assessment, NOAA Fisheries
- ^ Yahoo.com, Endangered turtle nests found in Texas
- ^ photo on Greenpeace USA Flickr via Louisiana Department of Wildlife and Fisheries
- ^ Kaufman, Leslie (May 18, 2010). "Gulf Oil Again Imperils Sea Turtle". The New York Times.
- ^ [1], centurylink.net, July 15, 2010
Bibliography [edit]
- Marine Turtle Specialist Group (1996). Lepidochelys kempii. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 9 May 2006. Database entry includes a brief justification of why this species is critically endangered and the criteria used
- Sizemore, Evelyn (2002). The Turtle Lady: Ila Fox Loetscher of South Padre. Plano, Texas: Republc of Texas Press. p. 220. ISBN 1-55622-896-1.
Unreviewed
Names and Taxonomy
Taxonomy
Comments: MtDNA data indicate that L. kempii is phylogenetically distinct from L. olivacea (Bowen et al. 1991).
Trusted



