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Sea Turtle Species Profiles
Loggerhead
Loggerhead Overview
- Listed as Vulnerable on the IUCN Red List
- Most common sea turtle in Florida
- Named for its large head
- Feeds on crabs, mollusks, encrusting animals attached to reefs and rocks
- Weighs 200 to 350 pounds and measures about 3 feet in length
- Nests in Florida from April through September
Loggerhead Sea Turtle
Scientific Name: Caretta caretta
IUCN/Conservation Status: Vulnerable
According to the International Union for the Conservation of Nature (IUCN), loggerhead sea turtles are listed as Vulnerable. Their status was amended in 2017, from a 2015 study that listed them as Endangered (Casale & Tucker, 2017). However, distinct population segments may be in serious decline. Loggerhead sea turtles are protected in the U.S. under the Endangered Species Act. They are also protected from being harvested in Cuba, Mexico, Bermuda, and the Bahamas. Under the Convention on International Trade in Endangered Species, also known as CITES, loggerhead sea turtles cannot be traded internationally between countries that have signed the agreement (Witherington & Witherington, 2015).
Habitat and Distribution: Loggerhead sea turtles are found worldwide, mainly in temperate waters outside of the tropics. In the summer months, in the United States, loggerheads can be found from Cape Cod, Massachusetts to the Gulf Coast of Florida. In the winter months, loggerheads migrate towards warmer waters and move south or offshore. Young loggerheads may circle the entire Atlantic Ocean in their first 10 years of life and later utilize habitats such as seagrass beds, channels, and rocky reefs.
Diet: Loggerheads are carnivores, known to eat jellies, sponges, crabs, and conch. Post-hatchling and juvenile loggerheads are more opportunistic and will eat a variety of invertebrates including Portuguese man-o-wars, dead insects, and sargassum shrimp. Subadults and adults are more specialized in their diet and will eat mainly crustaceans, such as spider crabs, horseshoe crabs, and queen conch.
Size: An adult loggerheads’ carapace typically measures 78 to 109 centimeters (31 to 43 inches) and can weigh between 150 and 375 pounds. Females will normally grow to be larger than males.
Distinguishing Characteristics: Loggerhead sea turtles have 5 lateral scutes on their carapace, which is a reddish-brown color. As hatchlings, the carapace of a loggerhead has raised scutes, this is thought to potentially make these smaller turtles more difficult to swallow by predators, such as sharks. Adult loggerheads are often found with epibiota, including barnacles and algae, living on their carapaces. These creatures and the loggerheads they live on have a commensalistic relationship, meaning the epibiota benefit from having a surface to live on but the loggerhead remains unharmed. Another defining feature of loggerheads is their broad head and neck, for which they are named. Their strong jaws are used for crushing shells, such as conch, when feeding.
Maturity and Reproduction: Loggerheads reach maturity at about 30 years of age. This species has been seen mating off the coast of southeastern Florida. Most loggerhead clutches have 1 paternity but can have multiple (Witherington & Witherington, 2015).
Nesting: In the United States, loggerhead nesting takes place from North Carolina to Mississippi. The large majority of loggerhead nesting occurs on the beaches of southeastern Florida. Loggerheads do not nest every year, but every 2 to 4 years. In a single nesting season, a female can lay anywhere between 3 and 6 nests. Loggerhead nests average 115 eggs and hatchlings typically emerge after incubating for about 2 months.
Fun fact: the most densely nested loggerhead beaches in the world are on the 9.5 miles of beach Loggerhead Marinelife Center monitors and in northeastern Oman, in the Middle East. Loggerhead nesting on LMC monitored beaches normally occurs from April to October. During the 2020 nesting season, 13,059 loggerhead nests were recorded between Tequesta, Jupiter-Carlin, and Juno Beach (Loggerhead Marinelife Center, 2021).
Conservation and Specific Human Impacts: Loggerhead sea turtles have not suffered from commercial harvest, like some sea turtle species have. However, loggerheads are often impacted by commercial fishing. Juveniles have been found to go after bait on longlines, while subadult and adult loggerheads are adversely affected by trawling, another form of commercial fishing. Being trapped in a trawl can restrict a sea turtle's ability to breathe and therefore often leads to drowning. It is estimated that because of commercial trawling, loggerhead numbers have decreased by tens of thousands. Some specific changes that have been made that positively impact loggerheads include the use of turtle excluder devices, (TED’s) on trawl nets, and requiring longline fishermen to use circle hooks (Witherington & Witherington, 2015).
Local Impacts: During the 2020 nesting season, Loggerhead Marinelife Center researchers documented that boat strikes were the most frequently recorded injury observed on nesting loggerhead sea turtles. (Loggerhead Marinelife Center, 2021).
Citations:
Casale, P. & Tucker, A.D. 2017. Caretta caretta (amended version of 2015 assessment). The IUCN Red List of Threatened Species 2017: e.T3897A119333622.
https://dx.doi.org/10.2305/IUCN.UK.2017-2.RLTS.T3897A119333622.en. Downloaded on 09 February 2021.
Loggerhead Marinelife Center. (2021) Loggerhead Marinelife Center Sea Turtle Monitoring 2020 Nesting Season Final Report. 9-16.
Witherington, B., & Witherington, D. (2015) Our Sea Turtles: A Practical Guide for the Atlantic and Gulf, From Canada to Mexico. Pineapple Press, Inc.
Green
Green Turtle Overview
- Listed as Endangered on the IUCN Red List
- Named for greenish color of body fat
- Feeds on seagrass and seaweed
- Adult females weigh 300 pounds and are 3-4 feet in length
- Nests in Florida from May through September
Green Sea Turtle
Scientific Name: Chelonia mydas
IUCN/Conservation Status: Endangered
Green sea turtles are protected under the U.S. Endangered Species Act and listed as Endangered by the International Union for Conservation of Nature (IUCN). Other countries where it is illegal to harvest these turtles include Cuba, Mexico, The Bahamas, and Bermuda. Greens are also protected from commercial trade under the Convention on International Trade in Endangered Species (CITES), which is especially important due to their historical population decline from commercial trading (Witherington & Witherington, 2015).
Habitat and Distribution: Green sea turtles are found in warm waters around the tropics and subtropics in the Pacific, Atlantic, and Indian Oceans. On the east coast of the U.S.in the summer months these turtles can be found as far north as Cape Cod, Massachusetts. Throughout a green sea turtle's life, it will utilize habitats such as beaches, pelagic sargassum, seagrass beds, and nearshore reefs (Witherington & Witherington, 2015).
Diet: Juvenile green sea turtles are known to be omnivores and feed on blue buttons, copepods, and sargassum crabs. As they age, green turtles’ gut bacteria undergo a change allowing them to transition to herbivores, feeding primarily on seagrasses and algae. Although they become herbivores as they age, an adult green sea turtle is unlikely to pass up easily accessible animal prey and may still consume creatures such as jellies (Witherington & Witherington, 2015).
Size: Adult females typically weigh between 265 and 485 pounds. Their carapace can be between 78 and 119 centimeters (31 to 47 inches). Like loggerheads, the males are slightly smaller than the females (Witherington & Witherington, 2015).
Distinguishing Characteristics: While some believe green sea turtles’ carapaces appear green, they were actually named for the green color of their muscles and fat, which are tinted green because of their herbivorous diet. They have a serrated beak to assist with eating seagrasses. These turtles can also be characterized by their 4 lateral scutes that do not overlap (Witherington & Witherington, 2015).
Maturity and Reproduction: Green turtles reach maturity between 20 and 40 years old. While they mature at different ages, they also mature at different sizes. A green turtle that is growing more quickly may also mature faster. During mating season males will migrate to waters off the females’ nesting beaches. Males are likely to mate with multiple females and a single clutch can have 2 to 3 paternities (Witherington & Witherington, 2015).
Nesting: The nesting beaches of green sea turtles are found in warmer latitudes, in areas such as southern Mexico, southern Cuba, Caribbean Costa Rica, and southeastern Florida. Other areas of green sea turtle nesting include Australia, Africa, and many islands of the Indo-Pacific. The majority of green sea turtle nests in the U.S. are found in Florida. An average green nest will contain about 135 eggs and incubate for about 2 months (Witherington & Witherington, 2015). Green sea turtle nesting on Loggerhead Marinelife Center’s monitored beaches occurs from May into October. In 2020, 3,590 green sea turtle nests were laid on these 9.5 miles of monitored beach (Loggerhead Marinelife Center, 2021).
Conservation and Specific Human Impacts: Green sea turtles were once one of the most abundant animals found on earth. Greens have been hunted for their meat for thousands of years, but because of an increase in commercial harvest, the last few hundred have been the most detrimental to their populations. During the European colonization of the Caribbean, the colonizers began harvesting green sea turtles and storing them on their ships to maintain a constant supply of fresh meat. In the seventeenth century, the British began shipping around 13,000 green sea turtles a year back to Europe. By the early 1800s, the green sea turtle population in the Cayman Islands had severely diminished. To put this into perspective, it was once thought that millions of green sea turtles nested there and today there are only a handful of nests recorded each season in this area, meaning the populations still have not recovered.
In the southeastern United States, Green sea turtle overharvest began in the 1800s. Initially, harvesting took place in Key West. However, by the 1900s, most local populations were gone. The turtle fishermen of Key West were able to continue their fishery by harvesting in the western Caribbean. Thanks to conservation efforts, green nesting numbers have been on the rise. Although these turtles usually follow a 2 year trend of higher nesting numbers followed by a dip, the overall data is showing an increase in nesting numbers (Witherington & Witherington, 2015).
Local Impacts: Similar to loggerheads, boat strikes were the most common injury reported in green sea turtles during the 2020 sea turtle nesting season recorded by LMC biologists. (Loggerhead Marinelife Center, 2021). See what our Conservation department is doing to promote Responsible Boating Initiatives: https://marinelife.org/conservation/rbi/
Citations:
Loggerhead Marinelife Center. (2021) Loggerhead Marinelife Center Sea Turtle Monitoring 2020 Nesting Season Final Report. 9-16.
Witherington, B., & Witherington, D. (2015) Our Sea Turtles: A Practical Guide for the Atlantic and Gulf, From Canada to Mexico. Pineapple Press, Inc.
Leatherback
Leatherback Sea Turtle Overview
- Listed as Vulnerable on the IUCN Red List
- Largest and deepest diving of the sea turtles
- Named for smooth, rubbery shell
- Feeds on jellyfish
- Weighs 700-1500 pounds and measures 4 to 8 feet in length
- Nests in Florida from March through July
Green Sea Turtle
Scientific Name: Dermochelys coriacea
IUCN/Conservation Status: Critically Endangered
Critically Endangered - Under the International Union for the Conservation of Nature (IUCN), leatherbacks are listed on the Red List as Critically Endangered, which means they are even closer to extinction than other animals that are listed as endangered. Leatherbacks, like all sea turtles, are also protected in the U.S. under the Endangered Species Act, as well as in Canada, Mexico, The Bahamas, and Cuba, by their regional laws. In order to protect leatherbacks from commercial trade, they are also listed under the Convention on International Trade in Endangered Species (CITES). Lastly, the Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC), plays an important role in protecting leatherback turtles because many of them come into the waters of the United States after nesting in other areas (Witherington & Witherington, 2015).
Habitat and Distribution: Having the widest habitat range of the 7 sea turtle species, leatherbacks can be found from the subarctic to the subantarctic during the summer months. However, juveniles are only found in tropical waters. Leatherbacks have been found foraging in various habitats such as deep offshore waters, as well as shallow coastal waters (Witherington & Witherington, 2015).
Diet: Leatherback sea turtles are a specific type of carnivore known as a medusavore, which means they feed specifically on jellies, comb jellies, and tunicates (Witherington & Witherington, 2015). They are known to eat their weight in jellies daily (Loggerhead Marinelife Center, n.d.).
Size: The average weight of an adult leatherback depends on whether the turtles are in nesting versus foraging season. Nesting female leatherback sea turtles will range from 600 - 1,100 pounds and foraging females can range from 800 - 1,300 pounds. Typical to sea turtle species, males will be slightly smaller than females. The largest leatherback ever recorded was about 2,000 pounds during foraging (Loggerhead Marinelife Center, n.d.). Fun Fact: Loggerhead Marinelife Center biologists have been working on a research study examining the body condition of nesting female leatherback sea turtles to find a baseline weight for this population. This process involves using a scale and pulley system on the beach to weigh the turtle! Check out the 2020 Nesting Season Week 8 Update: https://marinelife.org/2019/05/25/leatherback-nesting-season-week-8-update-body-condition-study/
Distinguishing Characteristics: Leatherbacks are the largest species of sea turtle in the world. Their carapace is not hard like the other sea turtle species, but rather leatherlike with bony plates underneath. Their carapace does not have scutes, but 5 distinct dorsal ridges that extend the length of their carapace. The carapace of a leatherback is a black to blue-black color with white splotches (Witherington & Witherington, 2015). Their leathery carapace allows them to dive to the deepest depths of any sea turtle species because it can compress to withstand extreme pressure (Loggerhead Marinelife Center, n.d.). Leatherbacks’ front flippers are the largest, in proportion to their body than any other sea turtle species and they are lacking claws. The beak of a leatherback has 2 fanglike cusps, which help while eating jellies. On the top of a leatherback’s head, there is a pink splotch that is associated with the pineal gland. Because this pink spot is lacking pigment, it allows for the transmission of light. This may be important in tracking the daily movements of their planktonic prey (Witherington & Witherington, 2015).
Maturity and Reproduction: Leatherbacks grow quickly and have many, varying estimations of when they reach maturity. Some believe leatherbacks reach maturity after 5 years, while others believe it is closer to 15, or even 25 to 30. It is believed that males gather in the waters near nesting beaches but much is unknown about leatherback mating. Typically, leatherback clutches only have 1 paternity (Witherington & Witherington, 2015).
Nesting: Most leatherback nesting takes place in the tropics. These turtles’ nests average 74 viable eggs and also contain smaller unviable eggs, called spacer eggs (Loggerhead Marinelife Center, n.d.). Leatherback eggs are the largest of all sea turtle species, at the size of a billiard ball. Females may lay 4 to 7 clutches and nest every 2 to 3 years. Depending on when they are laid in the season, leatherback eggs will incubate for 2-3 months (Witherington & Witherington, 2015). Nesting in south Florida occurs from March through July. Palm Beach County comprises about 30% of leatherback nesting in the state of Florida. During the 2020 nesting season, 286 leatherback nests were reported on the 9.5 miles of beach that Loggerheads Marinelife Center monitors. Of these leatherback nests, about 46% of eggs studied produce hatchlings according to LMC research (Loggerhead Marinelife Center, n.d).
Conservation and Specific Human Impacts: Over the past 3 generations, the global leatherback population has declined by approximately 40%. Some human impacts that leatherbacks are most at risk of are ingestion of marine debris, entanglement in fishing line, and unintentional boat strikes (NOAA, Leatherback Turtle, n.d.). Leatherbacks feed primarily on jellies, something that many have pointed out may look similar to plastic bags floating in the water.
Local Impacts: Fishing gear injuries and unintentional boat strikes were the most common injuries observed on nesting leatherbacks studied by LMC researchers in 2020. Atlantic leatherback nesting had been increasing but southeastern Florida has seen a decrease in the last 5 years. The cause of this drop has not been determined but could be related to an increase in human-related mortality (Loggerhead Marinelife Center, n.d.).
Citations:
Loggerhead Marinelife Center. (n.d.) The Leatherback Project. https://marinelife.org/seaturtles/research/leatherback/
NOAA Fisheries. (n.d.). Leatherback Turtle. https://www.fisheries.noaa.gov/species/leatherback-turtle
Witherington, B., & Witherington, D. (2015) Our Sea Turtles: A Practical Guide for the Atlantic and Gulf, From Canada to Mexico. Pineapple Press, Inc.
Hawksbill
Hawksbill Overview
- Listed as Critically Endangered on the IUCN Red List
- Has a beautiful shell, which is used for jewelry causing this turtle to be listed internationally as critically endangered
- Feeds on sponges
- Occasional nests are found in Palm Beach County each year
Hawksbill Sea Turtle
Scientific Name: Eretmochelys imbricata
IUCN/Conservation Status: Critically Endangered
Hawksbill sea turtles are considered to be Critically Endangered by the International Union for the Conservation of Nature (IUCN). This means this species is at high risk of extinction in the wild. In the United States, the hawksbill is considered Endangered under the Endangered Species Act and is also protected from harvest in Cuba, Mexico, The Bahamas, and Bermuda. Hawksbill sea turtles are protected from commercial trade under CITES, the Convention on International Trade in Endangered Species. Protections from commercial trade are critical for this species due to the trading of hawksbill shells that still occurs in some countries today. Hawksbills do not typically nest on any beaches of the U.S. Because hawksbills in U.S waters have traveled from the waters of other countries, the Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC) is important in protecting this species (Witherington & Witherington, 2015).
Habitat and Distribution: Hawksbill sea turtles are mainly spongivores, having a diet consisting largely of sea sponges. Because of their diet, the distribution of hawksbills follows that of coral reefs. They are found in tropical and subtropical areas. Most hawksbills near the U.S. are found in the waters of South Florida (Witherington & Witherington, 2015).
Diet: Hawksbills spend their first few years as opportunistic feeders, eating things such as dead insects, blue buttons, copepods, and hydroids. As they age, they use their specialized beak and long neck to eat mainly sponges and invertebrates from crevices on coral reefs. It is estimated that once they reach adulthood, sponges may comprise up to 95% of their diet. Fun Fact: The sponges that hawksbill sea turtles feed on are toxic, however, these toxins do not harm the turtles but instead bioaccumulate in their bodies, making their meat toxic to potential predators and humans (Witherington & Witherington, 2015).
Size: The carapace of an adult female hawksbill is between 76 to 89 centimeters (30 to 35 inches) and she will weigh between 100 and 150 pounds (Witherington & Witherington, 2015).
Distinguishing Characteristics: Hawksbill sea turtles can be identified by their 4 lateral scutes, which slightly overlap, similar to shingles on a roof. The scutes of a hawksbill are known for their colorful, plastic-like appearance and a wide variety of colors. Their scutes can have quite a bit of variation and can range from dark brown with lighter markings to lighter shades of brown. The beak of a hawksbill is where this turtle gets its name. It is narrow and strong, used for scraping sponges and other invertebrates off of reefs and crevices on coral reefs (Witherington & Witherington, 2015).
Maturity and Reproduction: Hawksbills reach maturity at about 25 years of age. Males and females mate along migration pathways and most hawksbills clutches have a single paternity (Witherington & Witherington, 2015).
Nesting: In our region of the world, hawksbill nesting takes place on tropical beaches in the southern Gulf of Mexico and the Caribbean. Hawksbills do not nest in incredibly high densities anywhere in the world. A female hawksbill will lay on average around 140 eggs, which will incubate for about 2-2.5 months. Females nest every 3 to 4 years and return to their natal beach to lay 3 to 5 nests. Hawksbill sea turtles do not nest in Florida. Hawksbill nesting season is from May to October (Witherington & Witherington, 2015).
Conservation and Specific Human Impacts: It is estimated that hawksbill nesting has decreased about 80% in the past century. The major reason for the serious decline in hawksbill populations is commercial harvesting. In the past, hawksbills have been harvested commercially for their unique shells and scutes. Originally, the tortoiseshell pattern we often see in glasses, jewelry, and other accessories came from harvested hawksbill shells but has now been replaced by plastic. These scutes are malleable and can be heated to be crafted into unique shapes. These items, as well as taxidermied hawksbills, used to be sold in tourist gift shops, which still happens in some countries today. Because of the Convention on International Trade in Endangered Species, trade of tortoiseshell has decreased. However, it has not completely stopped and illegal harvest and trade still do occur (Witherington & Witherington, 2015).
Citations:
Witherington, B., & Witherington, D. (2015) Our Sea Turtles: A Practical Guide for the Atlantic and Gulf, From Canada to Mexico. Pineapple Press, Inc.
Kemp's Ridley
Kemp's Ridley Overview
- Listed as Critically Endangered on the IUCN Red List
- Smallest of the sea turtles
- Nesting is mainly restricted to a 20-mile stretch of beach in western Gulf of Mexico
- Nesting often occurs in large aggregations during the daylight
- Feeds on blue crabs, clams, mussels, fish and jellyfish
- Adult weighs 85-100 pounds and measures 24-30 inches in length
Kemp's Ridley Sea Turtle
Scientific Name: Lepidochelys kempii
IUCN/Conservation Status: Critically Endangered
According to the International Union for the Conservation of Nature (IUCN), Kemp’s ridleys are considered Critically Endangered. This is a step higher from endangered and indicates that this species is at extremely high risk of extinction in the wild. The population decline largely stems from the species having one localized population and only two major nesting beaches in the world. They are also listed as Endangered under the U.S. Endangered Species Act, as well as protected in Cuba, the Bahamas, and Mexico. Like other sea turtle species, Kemp’s ridleys are protected under the Convention on International Trade in Endangered Species, which protects them from commercial trade in countries that have signed the agreement (Witherington & Witherington, 2015).
Habitat and Distribution: Kemp’s ridleys can be found in warm temperate waters in the western North Atlantic Ocean and the Gulf of Mexico (Witherington & Witherington, 2015).
Diet: Post-hatchlings and juvenile Kemp’s have been known to feed on hydroids, crabs, jellies, and other invertebrates. Juveniles and adults eat spider crabs, blue crabs, horseshoe crabs, and tunicates (Witherington & Witherington, 2015).
Size: Typically, an adult female Kemp’s ridley’s carapace will measure 61 to 71 centimeters (24 to 28 inches). They can weigh between 75 to 100 pounds (Witherington & Witherington, 2015).
Distinguishing Characteristics: Kemp’s ridleys are distinguishable from other sea turtles by their 5 lateral scutes and grey to olive-colored carapace, which is more circular than other species being wider than it is long. Kemp’s ridleys are also the smallest of the sea turtle species. Another unique characteristic of these turtles is their parrot-like beak (Witherington & Witherington, 2015).
Maturity and Reproduction: A Kemp’s ridley will reach maturity in about 12 years.
Most adult male Kemp’s ridleys live near the nesting beaches. In 1 Kemp’s clutch, the majority of the eggs are fertilized by 1 male, however, Kemp’s clutches have been known to have up to 4 paternities (Witherington & Witherington, 2015).
Nesting: Kemp’s ridley nesting takes place in 2 areas: almost all nesting occurs on the beaches of Tamaulipas, Mexico, with smaller scale nesting occurring in Texas (NOAA, Kemp’s Ridley Turtle, n.d.). Unlike other sea turtle species, Kemp’s ridleys are known for nesting during the day, in large groups called arribadas, which is Spanish for “arrivals.” Researchers do not know what triggers these mass nesting events, however, it is suggested that this type of nesting may be a defense against predators. Adult females nest every 1 to 3 years and may lay 2 to 3 nests. Each nest contains on average 103 eggs which will incubate for about 2 months. These turtles do not nest in Florida. Nesting season for this species is from April through June (Witherington & Witherington, 2015).
Conservation and Specific Human Impacts: Egg harvesting and drowning in commercial fishing trawls are thought to be 2 major threats to Kemp's ridleys. By the early 1900’s sea turtle egg collecting was common for people living on the coast. Egg collection has affected all species of sea turtle but was exceptionally detrimental to the Kemp's ridley population. By the 1960s their population was only about one one-hundredth of what it had been, 15 years prior. Trawling is the other major threat to Kemp’s ridleys and has killed hundreds of thousands of individuals of this species. This species is known to go after by-catch with trawling being a common practice in their habitat range. Kemp’s ridley arribadas were once known to have tens of thousands of individuals nesting, however, by the 1980’s it was rare for these nesting events to occur with over 200 turtles. Protecting their few nesting beaches, implementing regulations on trawls, and adding turtle excluder devices (TED’s) are some measures that have been taken to help Kemp’s ridley populations recover (Witherington & Witherington, 2015).
Citations:
NOAA Fisheries. (n.d.) Kemp’s Ridley Turtle. https://www.fisheries.noaa.gov/species/kemps-ridley-turtle
Witherington, B., & Witherington, D. (2015) Our Sea Turtles: A Practical Guide for the Atlantic and Gulf, From Canada to Mexico. Pineapple Press, Inc.
Olive Ridley
Olive Ridley Overview
- Listed as Vulnerable on the IUCN Red List
- Smallest of the sea turtles
- Turtles are an olive/grayish-green with a heart-shaped carapace
- Feeds on algae, lobster, crabs, tunicates, and mollusks
- Adult weighs up to 100 pounds and measures 24-36 inches in length
Olive Ridley Sea Turtle
Scientific Name: Lepidochelys olivacea
IUCN/Conservation Status: Vulnerable
According to the International Union of the Conservation of Nature, (IUCN) the olive ridley is considered Vulnerable (Abreu-Grobois & Plotkin, 2008). This indicates that the species is not endangered but populations are still at high risk of extinction in the wild. Olive ridleys are considered Threatened by the U.S. Endangered Species Act and therefore protected in the U.S. While the population of olive ridleys has decreased due to human causes, they are considered the most abundant sea turtles in the world (NOAA, Olive Ridley Turtle, n.d.).
Habitat/Distribution: The olive ridley can be found in tropical and temperate areas of the Pacific, Atlantic, and Indian oceans. Unlike the Kemp’s ridley, which prefers coastal waters, the olive ridley is found in open ocean habitats. This species cannot be found nesting in the U.S. but can be found passing through the Pacific waters of the West Coast, as far north as Oregon.
Diet: Olive ridleys are omnivores that eat shrimp lobsters, jellies, mollusks, tunicates, and algae.
Size: By the time they reach adulthood, olive ridley sea turtles measure 61 to 76 centimeters (2 to 2 and ½ feet) in length and weigh between 80 and 110 pounds.
Distinguishing Characteristics: The olive ridley is distinguishable by its varying number of lateral scutes. While other species have consistent numbers of lateral scutes, some olive ridley’s will only have 5, and others have as many as 9. They are named for their olive-colored carapace, which is heart-shaped and they look similar to Kemp’s ridleys.
Maturity and Reproduction: Olive ridley sea turtles mature between 10 and 18 years of age.
Nesting: Similar to the Kemp’s ridley, olive ridleys are known for nesting in arribadas. Females lay 1 to 3 nests per season with 100 to 110 eggs per nest. These nests will incubate for approximately 2 months before hatching. The most well-known nesting sites for the olive ridley are located on the coasts of Costa Rica, Mexico, and India. It is estimated that there are approximately 800,000 nesting females in the population.
Conservation and Specific Human Impacts: Threats that are specific to the olive ridley include poaching of eggs, loss of nesting habitat, and becoming bycatch in commercial fishing trawls. In order to protect olive ridleys, Mexico monitors and protects their nesting beaches. Mexico also established 17 reserve areas in 1986 and passed a law in 1990 to prevent egg poaching. Due to becoming bycatch in commercial fishing trawls, turtle excluder devices (TED’s) are now required on trawls in the U.S. and Mexico to reduce the accidental catch of these turtles. Because of these regulations, populations of olive ridleys in the waters of Mexico have stabilized. Take and bycatch from trawl nets remains a concern in the western Atlantic and Indian Oceans (United States Fish and Wildlife Service, n.d.).
Citations:
Abreu-Grobois, A & Plotkin, P. (IUCN SSC Marine Turtle Specialist Group). 2008. Lepidochelys olivacea. The IUCN Red List of Threatened Species 2008: e.T11534A3292503.
https://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T11534A3292503.en. Downloaded on 03 March 2021.
NOAA Fisheries. (n.d.). Olive Ridley Turtle. https://www.fisheries.noaa.gov/species/olive-ridley-turtle
US Fish and Wildlife Service: North Florida Ecological Services Office. (n.d.). Olive Ridley Sea Turtle (Lepidochelys olivacea).
https://www.fws.gov/northflorida/seaturtles/turtle%20factsheets/olive-ridley-sea-turtle.htm
Flatback
Flatback Overview
- Listed as Vulnerable on the Australian Commonwealth’s Endangered Species Protection Act
- Has the smallest geographic range of the seven sea turtle species
- This species lays an average of only 50 eggs per nest, larger hatchlings
- Feeds on sea cucumbers, jellies, soft corals, shrimp, crabs, molluscs, fish, and seaweed
- Adult weighs up to 200 pounds and measures 36 inches in length
Austrailian Flatback Sea Turtle
Scientific Name: Natator depressus
IUCN/Conservation Status: Data deficient
According to the International Union for the Conservation of Nature (IUCN) Australian flatbacks are Data Deficient, meaning there has not been enough research conducted to determine the current status of their population (Red List Standards & Petitions Subcommittee, 1996). In Australia, these sea turtles are listed as Vulnerable under the Environmental Protection and Biodiversity Conservation Act, which is similar to the U.S. Endangered Species Act, in that it provides a legal framework to protect areas of national environmental significance (Australian Government, 2008). There are some exceptions to the flatbacks’ legal protections because of the cultural and social value these turtles have for indigenous peoples. Sea turtles have important cultural significance for Aboriginal and Torres Strait Islander people and also provide a protein source in these areas where food may be expensive or difficult to obtain. These communities are working with scientists to ensure sustainable management of these species (Australian Government, n.d.).
Habitat/Distribution: As their name suggests, Australian flatbacks are found in the waters of Australia, as well as Papua New Guinea. Feeding occurs in the waters of Northern Australia. They prefer turbid waters and spend time in soft-bottom habitats such as seagrass beds. Flatbacks have the smallest range of all sea turtle species (Australian Government, n.d.).
Diet: Australian flatbacks are omnivores with a wide range of prey including sea cucumbers, jellies, mollusks, and other invertebrates.
Size: As adults, Australian flatbacks weigh about 200 pounds, and their carapace measures about 91 centimeters (3 feet) in length (Sea Turtle Conservancy, n.d.)
Distinguishing Characteristics: Australian flatbacks have an oval-shaped, olive to gray colored carapace with 4 lateral scutes and pale brown edges. Each scute has dark grey edges and a lighter gray center. Their carapace is flattened with upturned edges, which earned these turtles the name flatback. As adults, their carapace also has a thin, fleshy skin covering it (Australian Government, 2008).
Maturity and Reproduction: Australian flatbacks reach maturity sometime between 7 and 50 years of age (Ripple, 1996).
Nesting: Unlike other sea turtle species, the Australian flatback does not migrate to mate and nest because the only nesting populations are located in Australia. There are 4 major nesting areas along the coast of the country. These 4 populations each have different peak nesting seasons. One of these populations nests all year long, while another has a mid-summer peak and another has a mid-winter nesting peak. Females will lay about 50 eggs, which are relatively large in size. Their eggs incubate for approximately 2 months. Hatchlings are larger than most species.
Conservation and Specific Human Impacts:
Along with the Australian flatback being considered Data Deficient by the IUCN, there is also very little information about the major threats they face as a species. Some known threats include predation by feral pigs, being caught as bycatch, and loss of habitat. Feral pigs are an invasive species and are known for sniffing out flatback nests and feeding on up to 90% of the eggs. Similar to loggerheads, Kemp’s, and olive ridleys, threats posed by commercial fishing are known to impact the Australian flatback. Near Cape York, many adult flatbacks have been caught in ghost nets. In northwestern Australia, the construction of oil and gas facilities threatens flatback habitat and light pollution in these areas threatens hatchlings (Australian Government, 2008).
Citations:
Australian Government Department of Agriculture, Water, and the Environment. (n.d.) Marine Turtles in Australia.
https://www.environment.gov.au/marine/marine-species/marine-turtles
Australian Government Department of Agriculture, Water, and the Environment. 2008. Natator Depressus.
Red List Standards & Petitions Subcommittee. 1996. Natator depressus. The IUCN Red List of Threatened Species 1996: e.T14363A4435952.
https://dx.doi.org/10.2305/IUCN.UK.1996.RLTS.T14363A4435952.en. Downloaded on 09 March 2021.
Sea Turtle Conservancy. (n.d.) Information About Sea Turtles: Flatback Sea Turtle.
Key Terms
Adult - the point in a sea turtle’s life when they reach maturity, some species do not reach adulthood for 25-30 years; all stages of a sea turtle’s life are determined by an international standard of the length of their carapace
Arribadas - Spanish for “arrival by sea;” the synchronized, mass nesting of Kemp’s and olive ridley sea turtles
Blue buttons - a type of planktonic jelly-like animals that are a colony of animal cells, called polyps
Carapace- the upper portion of a turtle’s shell made up of bones and keratinous plates, called scutes
Commensalistic - a relationship between two organisms in which one benefits and the other does not benefit, but remains unharmed
Copepods - microscopic planktonic crustaceans
Epibiota - plants or animals living on the outside of a sea turtle’s shell
Ghost nets - a fishing net that has been lost in the ocean
Hatchling - the first stage of a sea turtle’s life; all stages of a sea turtle’s life are determined by an international standard of the length of their carapace
Hydroids - small predators related to jellies
Invasive species - an organism that is not native to an ecosystem that causes harm
Juvenile - the third stage of a sea turtle’s life, which they reach after post-hatchling, at this phase of their life, juvenile turtles tend to spend time in nearshore habitats; all stages of a sea turtle’s life are determined by an international standard of the length of their carapace
Light pollution - the presence of artificial man-made light
Longline - a type of commercial fishing where there is a main line that has many other lines with baited hooks attached in order to catch fish
Medusavore - a type of carnivore that specifically consumes jellies
Natal beach - the beach a sea turtle hatches from, females will return to this beach once they reach adulthood to nest
Pineal gland - a small structure in the brain that is part of the endocrine system; in leatherback sea turtles it is thought that their pink spot is associated with the pineal gland and their ability to sense light
Planktonic - plants and animals that do not have the ability to swim, but rather float through the ocean, for example, jellies
Post-Hatchling - the second phase of a sea turtle’s life, which they typically spend in floating sargassum mats while growing; all stages of a sea turtle’s life are determined by an international standard of the length of their carapace
Scute - a thickened plate on the back of a sea turtle, made from keratin
Spacer eggs - small unviable, yolkless eggs laid only by leatherback sea turtles
Subadult - the fourth stage of a sea turtle’s life right before they reach adulthood; all stages of a sea turtle’s life are determined by an international standard of the length of their carapace
Trawl - a large net that is pulled behind a boat in order to catch fish or shrimp
Spongivore - a type of carnivore that feeds specifically on sponges
Tunicates - soft-bodied organisms such as sea squirts
Sea Turtle FAQs
- General Questions -
What type of animal do you treat at LMC?
At LMC, we treat sick and injured sea turtles. While there are other kinds of turtles, such as land tortoises or freshwater turtles, our hospital specializes only in the treatment of sea turtles.
How many types of sea turtle are there in the world?
There are seven species of sea turtles in the world! The species are as follows: leatherback, green, loggerhead, hawksbill, Kemp's ridley, olive ridley, and Australian flatback. Scroll to the top of this page to learn more!
How do the sea turtle patients get their names?
The names we use are thought up by various means. Some are named after historic figures or holidays, others may be named by the turtle’s rescuer, a generous donor, a staff member, or volunteer.
Do you keep any sea turtles here permanently, or have any "resident" patients?
The patients admitted to The Sea Turtle Hospital at LMC follow a "Rescue-to-Release" protocol. This means that all patients admitted are taken through a treatment and rehabilitation process that aims for their recovery and eventual release back into the wild! We do not keep any patients here permanently. However, if our veterinary staff determines that a patient does not have the ability to be released back into the wild based on its condition, we will make arrangements for the animal to be transferred to another facility that hosts resident animals.
What do the sea turtle patients eat and when do we feed them?
In order to prepare our patients for eventual release back into the wild, our hospital staff takes all necessary precautions to reduce the amount of human interaction, especially in association with food. For this reason, we typically feed the patients before and after public hours to our facility. Common food items on our hospital's menu include fish, squid, crab or lobster, and a variety of greens like lettuce or green pepper.
Why do the sea turtles have to be separated in their tanks?
At our facility, the sea turtles are medical patients and each patient requires different care regimens and treatments, so it is best to keep them separated - similar to how patients in a human hospital may share a room but have separate hospital beds. In addition, sea turtles in the wild are considered to be solitary rather than social animals, therefore we provide them their own space while they are in our care.
Why can't we touch the sea turtles?
It is unlawful to touch, handle, or otherwise harass sea turtles. The sea turtle is an endangered species that is protected by state and federal regulations. As a rehabilitation facility, our trained hospital staff and volunteers are permitted to properly handle the sea turtle patients for the purposes of treatment and rehabilitation only. In the wild, it is unlawful to touch or otherwise harass a sea turtle and it is best practice to view wildlife from 150 feet or greater in distance.
How often do sea turtles need to breathe?
With sea turtles, the frequency of breathing can depend on size, medical condition, and activity level - for example, the larger turtles can typically spend more time underwater than the smaller ones, and a turtle that is more highly active will need to breathe more frequently.
What is the biggest predator for sea turtles?
As sea turtles grow in size, their predators change. The eggs of sea turtles can be a meal for foxes, raccoons, crabs, and other small carnivores. As hatchlings, their predators include birds, rodents and small carnivores, insects, and fish. As they grow into adults, their biggest natural predators are sharks. They also face threats from human impacts, both intentional and unintentional. Humans illegally harvest sea turtles for their meat, flippers and shells - called poaching. Many sea turtles are also impacted by unintentional commercial fishing techniques, and ever-developing coastlines disrupt nesting and hatch success.
How many sea turtle hatchlings reach adulthood?
It is hard to know for sure, but researchers estimate that approximately 1 in 1,000 to 1 in 10,000 eggs produce hatchlings that reach adulthood.
How old do sea turtles get?
The age of a sea turtle is an estimate based on the size of an animal, and it can vary between species. Researchers estimate that sea turtles can live to be over 80-100 years old!
In March of 2021, The Sea Turtle Hospital at LMC received the oldest and largest loggerhead patient that it had ever treated. Olmec, an adult male loggerhead sea turtle weighed over 358 pounds. Although we do not know the exact age, from the size of the turtle it was estimated that he was over 100 years old. Olmec underwent extensive, 24/7 medical therapy for pneumonia and a systemic infection but unfortunately passed overnight in our care. Treating Olmec has given our veterinary team significant insight into the largely unknown fields of geriatric sea turtle medicine and hospice care. It was truly an honor to treat this very old member of this ancient species.
Why do we have to turn off lights along the beach for the sea turtles?
Artificial lighting disrupts the nesting process of female sea turtles, and is one of the biggest threats for emerging hatchlings. Both hatchlings and nesting sea turtles rely on natural lighting such as moonlight to navigate their surroundings and find their way to the ocean, and artificial lighting can result in the turtles becoming disoriented. Disoriented hatchlings can fall victim to dehydration, loss of energy, and predation. By turning off lights at night, closing curtains, and avoiding any activity on the beach at night, you can help nesting turtles and hatchlings!
- Rescue -
Where do your sea turtle patients come from and how are they transported to your facility?
Our patients arrive at our hospital in a variety of ways. In some cases, our rehabilitation team will actively rescue and recover a sick or injured sea turtle and transport them to our hospital in our sea turtle ambulance! The Florida Fish and Wildlife Conservation Commission (FWC) will also transfer patients that they have locally rescued to our Sea Turtle Hospital at LMC. During nesting season, sea turtle hatchlings are often brought to us by members of the community that may find sick or injured hatchlings on the beach or along the coastline. See “Found a Sick or Injured Sea Turtle” for more information!
What should someone do if they find a sick or injured sea turtle?
If you have found an injured, deceased, or harassed Sea Turtle, or to report someone disturbing a sea turtle nest: Call: 1-888-404-FWCC (3922) - Cellular phone *FWC or #FWC
If you ever happen to come in contact with an injured or stranded sea turtle please call Florida Fish and Wildlife Conservation Commission (FWC) immediately at 1-888-404-FWCC (3922) or you may dial *FWC or #FWC on your mobile phone.
Once you have contacted FWC you are also welcome to call the center at our 24 hour Emergency Response number (561-603-0211
) if you are in need of assistance with the rescue. If a sick or injured turtle is observed at sea, please contact FWC directly and follow their instructions. Do not attempt to rescue the injured sea turtle as this could result in further injury to the animal or the rescuer.
If you are on a pier and a turtle is caught on a hook, contact Loggerhead Marinelife Center's 24 Hour Sea Turtle Rescue Line at (561) 603-0211 or FWC. See “Found a Sick or Injured Sea Turtle” for more information!
How many sea turtle patients does your hospital treat annually?
The Sea Turtle Hospital at LMC has admitted close to 2,000 sea turtles since opening in 1990. Each year, we typically receive over 100 patients. In 2019, we treated 153 sea turtle patients and in 2020 we treated 113!
- Rehabilitation -
What is the most common injury or illness you see in your patients?
Harmful boat interactions are one of the most common reasons for strandings in this area. Propeller-related trauma can damage any part of the turtle, and serious, permanent injury from motorcraft encounters can result in partial or full paralysis, buoyancy disorders, GI disease, and chronic debilitation. A turtle can become chronically debilitated because of several factors, all of which inhibit feeding or nutrient absorption, resulting in starvation. Check out LMC’s Responsible Boating Initiative.
How do you perform treatments on the sea turtles?
Daily medical treatments are performed in both the indoor and outdoor hospitals. Within the walls of the indoor hospital, we have a bloodwork laboratory, radiology suite, surgical suite, endoscopy and ultrasound, pharmacy and treatment room. We often perform treatments inside a drained tank if the patient is large and to reduce the stress of daily transportation to the indoor hospital.
Do you ever incubate sea turtle eggs in your hospital?
We do not collect eggs to incubate, and we do not raise hatchlings for release - all of the sea turtles, regardless of age, that pass through the hospital are here for medical treatment and rehabilitation. They are here until medically cleared for release, when they are returned to the wild.
Do you remove plastic if you find it in a sea turtle?
Most of the time, sea turtles are able to pass the plastics (or other foreign material) on their own with the help of treatment while in our hospital. In some severe cases, our veterinary staff may need to perform surgery to remove the foreign object(s). Based on our clinical studies, we estimate that 100% of hatchlings encounter or at risk of ingesting plastic during their first year of life.
Are there special medicines for sea turtles or other reptiles?
There are no sea turtle-specific medications at this time. Most hospitals use adapted doses of human medicine or other veterinary medicines (like those for cats, dogs, or even horses). Our hospital contributes important information in the study of medications in sea turtles, we are always learning something new!
How does marine debris impact sea turtles?
Sea turtles often mistake trash in the ocean as food items, or unintentionally ingest the debris while eating normal food items. They can also become entangled in debris like monofilament line, fishing nets, and rope. The turtle may also not be able to swim and dive while entangled in the debris, preventing them from feeding normally or evading predators.
- Release -
Do you tag and track all sea turtles when released?
All of our sea turtle patients (with the exception of hatchlings and post-hatchlings) receive two types of tags: metal flipper tags with a unique identifier (serial number) and a PIT tag similar to a microchip. On occasion, some of our larger patients that may receive satellite tracking tags which allow us to follow their movements for a limited time after release.
Do all of the patients in the hospital end up getting released?
The goal for all admitted patients to the Sea Turtle Hospital at LMC is for them to be released back into the wild following successful rehabilitation. In some cases, despite all efforts, a patient is determined to be non-releasable by our veterinary staff and depending on the condition of the animal, may be transferred to another facility.
How do you know when a patient is ready for release?
Our veterinary team determines when a patient is medically ready for release based on its health progress. Typically, the patient will have to be a healthy weight and be gaining weight at a normal rate, have normal bloodwork, and be off of all medications for several weeks. The hospital team will then work with the Florida Fish and Wildlife Conservation Commission (FWC) to determine a date and location for the release based on environmental conditions and the natural behavior of the species at its age class.
How do you know when a patient is ready for release?
Our veterinary team determines when a patient is medically ready for release based on its health progress. Typically, the patient will have to be a healthy weight and be gaining weight at a normal rate, have normal bloodwork, and be off of all medications for several weeks. The hospital team will then work with the Florida Fish and Wildlife Conservation Commission (FWC) to determine a date and location for the release based on environmental conditions and the natural behavior of the species at its age class.
Are your sea turtle releases open to the public?
The releases of our larger subadult and adult patients are often public releases that you can attend! Our smaller patients, like the juveniles and hatchlings, are privately released or taken offshore and released by boat. Check out our social media channels for live broadcasts and videos of our releases on Facebook, Instagram, and YouTube!
- Nesting Research -
What species of sea turtles nest in southeast Florida?
There are primarily three species that nest on our beaches in southeast Florida: the leatherback sea turtle, green sea turtle, and loggerhead sea turtle. Learn more about each species!
When is sea turtle nesting season?
Sea turtle nesting season in southeast Florida runs from March 1st to October 31st.
What does your research team study during sea turtle nesting season?
LMC has a highly trained research team of scientists who patrol 9.5 miles of beach from the northern border line of John D. MacArthur Beach State Park (southern extent of survey area) to the Martin County line during nesting season. Dawn nesting surveys are conducted daily from March 1 - October 31 each year, and serve to collect information regarding crawl counts, nest numbers, and reproductive success from three species of sea turtle nesting on our beaches!
How many eggs does a sea turtle lay in a nest?
The number of eggs in a nest can vary by species, and ranges from an average of 80 - 120 eggs in each clutch (nest).
What determines if a hatchling is a male or a female?
Sea turtles have what is called “temperature-dependent sex determination”, or TSD, which means that the temperature at which the eggs incubate determines the gender of the hatchlings. In sea turtles, warmer nest temperatures produce more females, and cooler nest temperatures produce more males. There can be a mix of both males and females in one nest!
Are all of the sea turtle nests marked?
Nests that we have discovered are all documented by GPS location. However, due to the high nest density on our beaches, only a portion of them are distinguished with a physical marker. Nests that are selected to be evaluated for hatch success will be identified with a wooden stake with a unique ID for accurate tracking and reporting.
What do I do if I find a hatchling or adult female on the beach?
While sea turtles are beautiful, captivating creatures, it is illegal to harm or harass sea turtles, their nests or hatchlings. Sea turtles are protected by the US Endangered Species Act of 1973 and Florida Statute Chapter 370.
Don’t:
- Don’t interact with or disrupt a nesting sea turtle
- Don’t use lighting on the beach at night including flash photography, or cell phones
- Don’t touch hatchlings on their way to the ocean
- Don’t take any action for empty egg shells, or exposed, un-hatched eggs
- Don’t harm or harass sea turtles, their nests or hatchlings
- Don’t use shovels to dig on the beach during nesting season
Adopt A Sea Turtle
You can support Loggerhead Marinelife Center by “adopting” a sea turtle patient starting at just $40. Your adoption directly benefits the continued care and treatment of our sick and injured sea turtles!