Sea Turtles & Reptiles
Leatherback Sea Turtle
Dermochelys coriacea
ALSO KNOWN AS
Leatherback, leathery turtle
DISTRIBUTION
Global oceans; tropical to cold temperate waters
ECOSYSTEM/HABITAT
Coastal to open ocean; deep diver
FEEDING HABITS
Omnivore (mostly feed on jellyfish)
TAXONOMY
Order Chelonii (turtles & tortoises); Family Dermochelyidae (leatherback sea turtles)
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Leatherback sea turtles have been swimming around the world’s oceans for more than 90 million years. They are the largest living turtle in the world, growing to more than two meters long and weighing 900 kilograms. Their preferred food is jellyfish, but because they are not very nutritious, each turtle needs to consume enough jellyfish to match its own body weight every day! To help them capture and eat these soft-bodied animals, they have a sharply pointed cusp at the end of their snout for piercing, and backward-pointing spines all the way down their throat to help swallow their slippery prey.
Leatherback sea turtles have been swimming around the world’s oceans for more than 90 million years. They are the largest living turtle in the world, growing to more than two meters long and weighing 900 kilograms. Their preferred food is jellyfish, but because they are not very nutritious, each turtle needs to consume enough jellyfish to match its own body weight every day! To help them capture and eat these soft-bodied animals, they have a sharply pointed cusp at the end of their snout for piercing, and backward-pointing spines all the way down their throat to help swallow their slippery prey.
Leatherback sea turtles are the only sea turtle that lack a hard shell, called a “carapace.” Instead, the back of a leatherback is made up of a layer of leathery skin with seven pronounced ridges on its back. This skin covers a layer of fat, tissue, and thousands of bony plates held together with cartilage to form the base of the “shell.” Leatherbacks are blue-black in colour with greyish-white spots, while their underside is a much lighter pinkish-white colour. They also have a unique patch on the top of their head that is this same pinkish-white colour, but its shape is different for every turtle; much like a human fingerprint.
Leatherbacks are also unique among sea turtles because they are the only species that lacks claws on both its front and rear flippers. Their front flippers are extremely long, often about as long as half the length of their body, while their back flippers are much smaller and are used as rudders.
Leatherback sea turtles spend their entire lives at sea, with only females coming ashore every two to three years to lay eggs on sandy beaches. In the Atlantic, nesting generally occurs from February to August, while in the Pacific leatherbacks nest at any time of year, and always on tropical beaches. Each female will nest about six times per season. Females re-migrate to the region in which they were born, and often to the same beach they were born, to lay and bury clutches of about 80 eggs. After about two months, the hatchlings will emerge from the nest and make a mad dash to the sea.
The life of leatherbacks out on the open ocean is not well understood and more research is needed, however, we do know that they migrate long distances for feeding and nesting. Research on sea turtle migration has shown that more than 50 per cent of leatherbacks in Canada’s Atlantic waters come from the island of Trinidad. Leatherbacks come to Canada’s coastal waters to feed, as this area provides critical foraging habitat. Due to the high productivity of our colder, temperate waters, there are high concentrations of jellyfish and other prey items for leatherbacks to feed on.
The eggs of leatherback sea turtles have been harvested for centuries by people as a food source, even though it is now illegal to trade them as indicated under the Convention on International Trade in Endangered Species (CITES). There is no targeted fishery for sea turtles in Canadian waters, but there are unintentional interactions observed in many fisheries. Leatherbacks have been caught incidentally as bycatch in pelagic (open ocean) longline fisheries, gillnet fisheries and, rarely, trawl fisheries along Canada’s coasts. There is high mortality of turtles caught in trawl and gillnet fisheries by drowning, however there is high post-release survival of turtles caught by pelagic longline since these fisheries occur closer to the surface of the water and allow the turtles to surface to breath even if they are hooked on a line.
There are also numerous incidents of turtle entanglements in fishing lines associated with pot and trap fisheries, buoy and anchor lines for other fisheries, and in abandoned ropes and cables at sea. These entanglements can weigh down turtles, making it difficult for them to catch prey, potentially cutting into their skin and causing infection, and even leading to drowning if they cannot surface to breath.
In 2012, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) listed both the Atlantic and Pacific population of leatherback sea turtles as Endangered. It is estimated that there are fewer than 30,000 nesting females worldwide today, due to human development on and destruction of nesting beaches, harvesting of eggs (which is now illegal but is still commonplace), and negative interactions with fisheries as bycatch. Both Atlantic and Pacific populations have also been listed under Schedule 1 of the Species at Risk Act (SARA) as Endangered, which has led to developing a recovery plan for leatherbacks in Canadian waters.
Oceana Canada is working to protect Canada’s oceans for species like the leatherback sea turtle. Find out more about our campaigns and join us in helping to bring abundance back to the ocean.
Committee on the Status of Endangered Wildlife in Canada – assessment report
Fisheries and Oceans Canada – Atlantic population
Fisheries and Oceans Canada – Pacific population
Fisheries and Oceans Canada – recovery strategy
NOAA Fisheries – species directory
Species at Risk Public Registry – species profile
