B.C. Reptiles & Amphibians

Credit: Claudia Lombard

Pacific Leatherback Sea Turtle

Dermochelys coriacea schlegeli

Description

The Pacific Leatherback Sea Turtle, henceforth called the Leatherback Sea Turtle, is the largest turtle species in the world, reaching a maximum length of over 2 m and weight of over 700 kg. The body is dark gray to bluish-black with white or light blue blotching and spots, and adults have a pink spot on the head. The limbs are modified into large clawless flippers, with the front flippers being particularly large at nearly half the length of the carapace. The Leatherback Sea Turtle gets its name from its shell that is devoid of scales but is instead covered with leathery skin and has seven longitudinal ridges. The plaston is light coloured, often pinkish-white, and have 5 longitudinal ridges.

Listen to the Indigenous words for “turtle” here!

Similar Species

In British Columbia, the Pacific Leatherback may be superficially confused with either the Green Sea Turtle, Olive Ridley Sea Turtle, or the Loggerhead Sea Turtle. However, Leatherbacks are substantially larger than either of these species and no other sea turtles have a leathery shell with longitudinal ridges.

Pacific Leatherback Sea Turtle

Olive Ridley Sea Turtle

Loggerhead Sea Turtle

Green Sea Turtle

Distribution

The Leatherback Sea Turtle has a global range that is the broadest of all the sea turtle species. It is found in all of the tropical and subtropical oceans, is sometimes spotted in temperate waters, and has even been reported within the Arctic Circle. There are three major, genetically distinct populations around the world; one of which occurs seasonally off the coast of British Columbia and uses the mouth of the Columbia River as a major feeding area. This population makes migrations between foraging sites and nesting sites across the Pacific from west to east. In British Columbia, Leatherbacks have been periodically observed in low densities during the summer in warm, productive coastal waters, particularly off the west coast of Vancouver Island.

Leatherback Turtles are at risk of global extinction, thus, information on distribution and population sizes is very important. If you see a Sea Turtle report your sightings!

British Columbia Cetacean and Sea Turtle Sightings Network (BCCSN)
1-866-I SAW ONE (1-866-472-9663)

Habitat

The Leatherback Sea Turtle is a highly migratory species that has been documented travelling up to 20,000 km in extreme cases. Hatchling Leatherback Sea Turtles immediately make their way to the ocean and are rarely seen again until they mature. Adult and subadult turtles split their time between tropical waters and cooler temperate waters, most commonly near land in feeding areas. Nesting occurs on beaches in tropical and subtropical areas, although males will never leave the water in their life. Leatherbacks are able to venture into cooler temperate waters more often, and for longer, than other species of sea turtle, as they are able to generate body heat through muscle movement and can conserve this heat efficiently thanks to their large mass and small surface area.

Reproduction

Leatherback Sea Turtles mate at sea, and while females crawl on land to nest, males never leave the water. Females will generally mate every 2-4 years, but may breed and nest every year in particularly productive areas. With such a broad global distribution, the nesting period varies with location and hemisphere. Most sea turtles return to the same beaches where they were hatched, but female Leatherbacks will sometimes nest on other beaches in the same region. They prefer their nesting beaches to have soft sand and few offshore reefs or rocks. Females excavate a nest cavity deeper than 1 m and above the high tide line and will lay up to 11 clutches with an average of 110 eggs spread 8-12 days apart. Hatchlings emerge after about 2 months, and the sex of the offspring is temperature dependent; temperatures below 28.75 °C produce only males, temperatures above 29.75 °C produce only females, and moderate temperatures will produce a mix of sexes. Leatherbacks reach sexual maturity between 6-15 years of age. The maximum lifespan is unknown, but it is assumed that, like other sea turtles, they live for well over 50 years.

Diet

Leatherback Sea Turtles are thought to be jellyfish specialists. They will congregate at schools of jellyfish and are apparently immune to their stinging tentacles, and have backward projecting spines in their throats that aid in swallowing their slipper prey. Although they primarily feed on jellyfish, they will also eat sea urchins, snails, crustaceans, and small fish. Very little is known about the feeding habits and behaviours of juveniles.

Conservation Status

Global: G2 (2014)

COSEWIC: E

SARA:1-E (2017)

Provincial: S1N (2018)

BC List: Red

Learn more about conservation status rankings here

Threats

The Leatherback Sea Turtle is listed as endangered under the Canadian Species at Risk Act, and is considered critically endangered on a global scale. They are at risk of extinction if current trends do not reverse. Atlantic Leatherback Turtles appear to be relatively stable, but Pacific populations have declined by approximately 95% in recent decades. Their long lifespan, very high rate of egg and hatchling mortality, and late age of maturity make Leatherback Turtles particularly vulnerable to even small increases in mortality rates in adults and older juveniles. The primary cause of mortality in Canadian waters is incidental capture in fishing gear. Other activities that threaten this species include meat and egg harvest, and malnutrition and intestinal blockage via the consumption of plastic bags that resemble their jellyfish prey. Climate change may also negatively affect Leatherbacks through increased erosion of nesting beaches, or temperature fluctuations that result in skewed sex ratios of hatchlings.

Did You Know?

Fact #1

Unlike most reptiles, Leatherback Sea Turtles are able to generate internal heat and maintain body temperatures higher than the surrounding environment. Several adaptations allow this to happen such as fat layers, concurrent blood flow in the flippers, a low surface area to volume ratio, and the generation of heat through metabolic activity similar to endotherms. The metabolic rate and body temperature of Leatherbacks can be up to 18 °C higher than the surrounding water, allowing them to spend extended periods in colder waters at northern latitudes.

Fact #2

The Leatherback Sea Turtle can descend deeper than 1,200 m and are among the fastest moving reptiles in the world, reaching swimming speeds of up to 35 km/hr.

Fact #3

Scientists once tracked a Leatherback Sea Turtle that swam from Indonesia to the United States, covering over 20,000 kilometers over a period of 647 days.

Species Account Author: Marcus Atkins

References

B.C. Conservation Data Centre. 2005. Species Summary: Dermochelys coriacea. B.C. Minist. of Environment. Available:https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 23, 2021). 
B.C. Conservation Data Centre. 2018. Conservation Status Report: Dermochelys coriacea. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 23, 2021). 
B.C. Conservation Data Centre. 2021. BC Species and Ecosystems Explorer. B.C. Minist. of Environ. Victoria, B.C. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 23, 2021).  
COSEWIC. 2012i. COSEWIC assessment and status report on the Leatherback Sea Turtle Dermochelys coriacea in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xv + 58 pp. 
Department of Fisheries and Oceans. 2015c. Report on the Progress of Recovery Strategy Implementation for Leatherback Sea Turtles (Dermochelys coriacea) in Canadian Pacific Waters for the Period 2007-2012. Species at Risk Act Recovery Strategy Report Series. Fisheries and Oceans Canada, Ottawa. v + 12 pp. 
Pacific Leatherback Turtle Recovery Team. 2006. Recovery Strategy for Leatherback Turtles (Dermochelys coriacea) in Pacific Canadian Waters. Species at Risk Act Recovery Strategy Series. Fisheries and Oceans Canada, Vancouver, v + 41 pp. 
http://canadianherpetology.ca/species/species_page.html?cname=Leatherback%20Sea%20Turtle 
http://linnet.geog.ubc.ca/efauna/Atlas/Atlas.aspx?sciname=Dermochelys%20coriacea&ilifeform=43 
https://www.bcreptiles.ca/turtles/pacleatherback.htm