Sea turtles are a fundamental link in marine ecosystems. They help maintain the health of sea grass beds and coral reefs that benefit commercially valuable species such as shrimp, lobster and tuna. Sea turtles are the live representatives of a group of reptiles that have existed on Earth and traveled our seas for the last 100 million years. Turtles have major cultural significance and tourism value. Marine turtles can lay more than 150 eggs per clutch, and lay several times each season, to make up for the high mortality that prevents most marine turtles from reaching maturity.
Hunting and egg collection for consumption are major causes of the drastic decline in marine turtle populations around the world. Marine turtle eggs are considered an aphrodisiac in some countries and eaten raw or sold as snacks in bars and restaurants.
Each year, tens of thousands of turtles are trapped in shrimping operations. Marine turtles are reptiles so when they cannot reach the surface to breathe, they drown. Gill nets and long-line fisheries are also principal causes of marine turtle mortality. Marine turtles are caught annually in trawls, on long-line hooks and in fishing nets.
High demand and market prices for marine turtles shells – particularly the hawksbill – and leather products made from leatherback turtles, threatens the populations of these vulnerable species.
Changing climate and global warming have the potential to seriously impact marine turtle populations. Marine turtles have temperature-dependent sex determination. A change in global temperatures alters sand temperatures, which then affects the sex of hatchlings and increases the risk for population instability.
Marine turtles can mistake floating plastic materials for jellyfish and choke to death when they try to eat them. Discarded fishing gear entangles marine turtles and can drown or render a turtle unable to feed or swim. Rubbish on beaches can trap hatchlings and prevent them from reaching the ocean. Oil spills can poison marine turtles of all ages.
Uncontrolled development has led directly to the destruction of critically important nesting beaches. Lights from roads and buildings attract hatchlings and disorient them away from the sea. Human and vehicle traffic, along with beach restoration projects that include dredging and sand filling, destroys nearshore feeding grounds and alters nesting beaches.