Sea turtle

Sea turtles are large, ocean-going reptiles adapted for life in marine environments and known for long migrations and nesting on land.

Sea turtles are large, ocean-going reptiles adapted for life in marine environments. They are known for their long migrations and nesting on land, with seven living species recognized worldwide. Sea turtles have existed for more than 100 million years, but many populations are now threatened by human activity and habitat loss.

Classification and biology

Sea turtles are marine reptiles belonging to the order Testudines. Their streamlined bodies and flippers are adapted for swimming long distances, and they have beak-like jaws suited to various diets. Like all reptiles, they breathe air and must come ashore to lay eggs.

Species

There are seven living species of sea turtles, divided into two families: Cheloniidae and Dermochelyidae. The leatherback is the largest species, and the flatback is endemic to the waters around Australia and Papua New Guinea. The other species include the green, loggerhead, hawksbill, Kemp’s ridley, and olive ridley.

Distribution and life cycle

Sea turtles inhabit tropical and temperate oceans worldwide, migrating long distances between feeding grounds and nesting beaches. Most species exhibit natal homing, returning to the same general areas where they were born to lay their eggs. Females come ashore to nest, and hatchlings begin life on land before moving to the sea.

Conservation

Sea turtles face numerous threats, including habitat loss, pollution, entanglement in fishing gear, climate change, and poaching. Their conservation status varies by species and population, with several listed as threatened, endangered, or critically endangered. In Canadian waters, leatherback sea turtles are a species of concern and are part of marine conservation and fisheries policy.