Fisheries and Oceans Canada
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Sea Turtles
The Sea Turtle has been found in the world's ocean for more than 100 million years. Two of the seven distinct types of sea turtle are found in Canadian waters: the Leatherback and the Loggerhead.
The Leatherback is the world's largest reptile – and the only sea turtle that does not have a hard shell. It can measure up to 2.4 metres in length and 3.6 metres in width, and can weigh up to 725 kilograms. The carapace (upper shell) of the leatherback is dark and bluish-black in colour and covered with leathery skin. The turtle has front and rear flippers (the front often half as long as its carapace), but unlike other sea turtles, these flippers have no claws. Its body is shaped like a teardrop, tapering at the rear, and the bottom of its shell is pinkish-white. Each leatherback turtle has a unique pink patch on the top of its head.
Photo: Courtesy of the Nova Scotia Museum of Natural History
The Loggerhead has a large head and blunt, powerful jaws, and can weigh up to 100 kilograms. This type of sea turtle has a hard shell, which is reddish-brown in colour and can reach up to one metre in length. The underside of the shell, called a plastron, is a yellow in colour, and the flippers are dark brown with white margins. The loggerhead has vast migrations, and can be found in the Atlantic Canada's waters down to Argentina and in the Pacific from Alaska through British Columbia and down to Chile and across to Asia.
One of the oldest surviving species on earth, sea turtles have always faced natural predators on land and in water; particularly, as eggs and hatchlings and during the first few years in the water. However, scientific research now suggests that the greatest risk today is the activities of humans. These include:
- Illegal hunting and shell collecting from beach nests. Sea turtle meat, eggs, shells and oils are highly sought after in certain Asian and European markets.
- Incidental by-catch by fishers, especially those using long lines, gill nets and trawls. Entangled in these devices, sea turtles have a lot of difficulty getting free.
- Coastal development of beachfront nesting areas, seafloor dredging, vessel traffic, construction, and alteration of vegetation
- Pollution and debris in the water, such as plastics, can be mistaken as food or turtles can become entangled in them. Chemical pollutants can also have a devastating impact on the health of sea turtles.
- Climate change, including changes to water temperature and water levels, and increases in the number of extreme storms, can negatively affect breeding patterns and contribute to habitat destruction.
The World Conservation Union's (IUCN) list of endangered species includes all sea turtles around the world. The IUCN bases their assessments on the status of sea turtles through surveys of reproduction activity at nesting beaches. According to their assessments, for example, Leatherback turtle nesting in the Pacific regions has declined by more than 80 per cent. In other areas of its range, observed declines are not as severe, with some populations showing trends towards increasing or stable nesting activity.
The leatherback has also been listed in the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). Canada signed this treaty, as have many of the countries that host nesting or migratory populations of leatherbacks. CITES attempts to ensure that trade in endangered species do not threaten the existence of those species.
Fisheries and Oceans Canada is a partner of the Canadian Sea Turtle Research Project, which monitors the distribution, movement, and population dynamics of leatherbacks and other sea turtles in Canadian waters. As part of this collaboration, the Department is working to demonstrate the importance of protecting juvenile and adult turtles to ensure their survival.
In Pacific, DFO is implementing a national Leatherback turtle recovery strategy and action plan that began in 2003, to ensure the long-term viability of leatherback in this area. In the Atlantic, DFO is working with the Nova Scotia Leatherback Turtle Working Group and Myers Research Lab at Dalhousie University in Halifax, to achieve similar goals.
Internationally, the Northwest Atlantic Fisheries Organization (of which Canada is a member) is presently studying the incidental by-catch of sea turtles and ensuring the safe handling of any turtles that are caught in this way. Scientific information gathered on sea turtles is shared amongst NAFO members.
Canada continues to work closely with other fishing nations and through regional fisheries management organizations to ensure that best management practices for sea turtles are implemented in Canadian fisheries and globally. In particular, Canada will look to continue collaboration with countries like the United States, in the provision of scientific data and the implementation of consistent management approaches for marine turtles in Northwest Atlantic waters.
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