The largest of all sea turtles, and one of the largest reptiles on earth, the leatherback turtle ranges in size from 4-8 feet in length (1.2 - 2.4 meters) and weighs between 500-2,000 pounds (225 - 900 kg). The average adult measures in between 5-6 feet (1.5 - 1.8 m) and weighs 600-800 pounds (270 - 360 kg).

The oldest of all sea turtle species, it has been around for more than 150 million years! They survived the extinction of the dinosaurs and thrived until the last several decades when human interactions have taken a major toll.


  • Leatherbacks can consume twice their own body weight in prey per day, feeding exclusively on soft-bodied invertebrates like jellyfish and tunicates. Learn more about their diet.
  • They have downward curving spines (also known as papillae) in their mouth and throat which help them to capture and swallow their prey.
  • Unlike all other sea turtles, these giants do not possess a carapace (shell) covered with hard scales, also known as scutes. Their smooth, leathery skin covers a flexible matrix of bone. This specialized, flexible carapace allows them to dive to great depths unlike other species. 
  • Their widespread distribution and ability to tolerate cold water are due to thermoregulatory adaptations (called gigantothermy) which allow them to maintain their core body temperature.
  • They are considered Vulnerable around the world by the IUCN Red List and listed as Endangered in the US.
  • Their scientific name is Dermochelys coriacea.

Green Turtles
The green turtle is the second largest after the leatherback. They can weigh up to 500 lbs (225 kg) and reach four feet (1.2 m) in length. The adult is an herbivore, dining on sea grasses, seaweeds, algae and other forms of marine plant life. Their beak is sharp and finely serrated, perfectly adapted for grazing in seagrass beds and scraping algae off of hard surfaces.

This species is the only one to come on shore regularly to bask. Basking only occurs in Hawaii, particularly the Northwestern Hawaiian Island chain, the Galapagos Islands, and in some areas of Australia.


  • These turtles are believed to improve the health of seagrass beds and associated microhabitats. They will graze the beds, taking off the tops of leaf blades, while avoiding the roots. The seagrass will grow healthier and faster with a daily trim!  Learn about their diet.
  • Greens in the Eastern Pacific are called Pacific Black turtles and some researchers believe they are a separate species. Their coloration is not black, but their skin pigmentation is darker than other green turtles, making them appear darker overall. They are also smaller and their carapace is slightly different in shape.
  • Their name comes from the color of their fat, not their shell, as commonly believed.
  • They are listed as Endangered in the US and around the world by the IUCN Red List.
  • Their scientific name is Chelonia mydas.
One of the larger species of sea turtles, the loggerhead turtle ranges from 200-400 pounds (90 - 180 kg) and up to 4 feet in length (1.2 meters). They occur throughout temperate and tropical regions of the Pacific, Indian, and Atlantic Oceans.

One of the most abundant of the species found in the US, they are named for their large head and strong crushing jaw (right) which enables them to eat hard-shelled prey such as crabs, conchs, and whelks.


  • One population of these turtles nests in Japan and migrates across the entire Pacific Ocean to the rich feeding grounds off the coast of Baja California Sur, Mexico, where they spend several years foraging and maturing.
  • In the US, most of their nests are laid in Florida, however in the last decade the number of nests in Florida has declined by 40%.
  • They are listed as Endangered around the world by the IUCN Red List and Threatened in the US.
  • Their scientific name is Caretta caretta.
Considered by many to be the most beautiful of sea turtles for their colorful shells, the hawksbill is found in tropical waters around the world. They spend their time in coral reefs, rocky areas, lagoons, mangroves, oceanic islands, and shallow coastal areas.

Named for its narrow head and sharp, bird-like beak, hawksbills can reach into cracks and crevices of coral reefs looking for food. Their diet is very specialized, feeding almost exclusively on sponges. One of the smaller turtles, adults weigh between 100-200 pounds (45 - 90 kg) and reach 2-3 feet (roughly .5 to 1 meter) in length


  • These turtles are solitary nesters, nesting in low densities on small scattered beaches. Adult females are well adapted for crawling over reefs and rocky areas to reach secluded nesting sites.
  • On average, they nest roughly 4 times per season at 2 week intervals and lay around 140 eggs per nest. Nests however, may contain over 200 eggs!
  • Hawksbills are considered Critically Endangered around the world by the IUCN Red List and are listed as Endangered in the US. Some researchers believe the Eastern Pacific hawksbill is likely the most endangered sea turtle population worldwide.
  • Their scientific name is Eretmochelys imbricata.
Olive Ridleys
The second smallest after the Kempís ridley, the olive ridley turtles weigh between 75-100 pounds (34 - 45 kg) and reach 2-2 Ĺ feet (roughly .6 m) in length. They are named for their pale green carapace, or shell and are the most abundant of sea turtle species.

Like the Kempís ridley, nest in masses referred to as arribadas. During arribadas, thousands of females may nest over the course of a few days to a few weeks. Adults reach sexual maturity around the age of 15 years.


  • There are only a few places in the world where olive ridley arribadas occur (see Distribution below for sites). In other parts of the world, they are solitary nesters.
  • Though arribadas are not well understood, the timing is thought to coincide with weather events such as strong winds or cloudy days, or with moon and tide cycles. The turtles congregate in large groups offshore of nesting beaches and then simultaneously come ashore to nest. Females may remain offshore near nesting beaches throughout the nesting season.
  • These turtles are omnivores, eating a variety of prey including crabs, shrimp, lobster, urchins, jellies, algae, and fish. In Baja California, Mexico, their preferred prey is the red crab which is abundant in offshore waters. Learn more about their diet.
  • Despite their relative abundance in comparison to other sea turtles, this species is considered Vulnerable by the IUCN Red List and is listed as Threatened in the US.
  • Although they are the most abundant species, their numbers have decreased by approximately 50 percent since the 1960’s. Their scientific name is Lepidochelys olivacea.