Sea Turtles
Oil Spills
Fisheries by Catch
Worldwide, hundreds of thousands of sea turtles a year are accidentally caught in shrimp trawl nets, on long line hooks and in fishing gillnets. Sea turtles need to reach the surface to breathe, and therefore many drown once caught. Known as by-catch, it is a serious hazard for green turtles. As fishing activity expands, this threat is more of a problem.
Habitat Loss
Sea turtles are also dependent on beaches for nesting.
Relating it to climate change
Because sea turtles use both marine and terrestrial habitats during their life cycles, the affects of climate change are likely to have a devastating impact on these endangered species.
- For five of the seven species of sea turtles, the Gulf is where they live, migrate and nest. The Hawksbill, Green, Leatherback, Loggerhead and Kemp’s Ridley are all listed as either threatened or endangered.
Oil Spills
- Oil can have damaging effects on sea turtles at every stage of their lives.
- Eggs contaminated with even the slightest bit of oil can fail to hatch or produce ill or deformed hatchlings.
- Because of their small size, hatchlings that make their way from the beach to the water can become overwhelmed by an oil slick.
- Young turtles tend to swim on the water’s surface; encountering oil as they go that can poison or coat them.
- Finally, adults can ingest oil as they surface for air and sometimes even feed on tar balls.
- Oil spills from exploration for and transportation of oil and gas, as well as from urban and agricultural run-off, poses substantial risks to marine turtles and to the habitats they rely upon.
- Oil from spills and leaks that sit on the surface of the water doesn't really stick to sea turtles like it would to other marine species.
- But oil can get in their eyes, on their skin, and in their lungs when they come to the surface to breathe.
- Although turtles maybe the toughest in terms of resisting some of the immediate physical damage from oil spills, they have proved to be more vulnerable to chemical exposure that happens indirectly through the food they eat.
- Not only do larger spills pose a problem for the turtles, studies have shown that continuous exposure over time will weaken a sea turtle's overall health, making it more susceptible to other dangers.
- The green turtle is one of the largest sea turtles and the only herbivore among the different species.
- Green turtles are in fact named for the greenish color of their cartilage and fat, not their shells.
- Green turtles are found mainly in tropical and subtropical waters.
- Like other sea turtles, they migrate long distances between feeding grounds and the beaches from where they hatched.
- Classified as endangered, green turtles are threatened by overharvesting of their eggs, hunting of adults, being caught in fishing gear and loss of nesting beach sites.
- Green turtles graze on sea grasses and algae, which maintain the sea grass beds and makes them more productive (much like mowing the lawn to keep it healthy).
- Sea grass consumed by green turtles is quickly digested and becomes available as recycled nutrients to the many species of plants and animals that live in the sea grass ecosystem.
- Sea grass beds also function as nurseries for several species of invertebrates and fish, many of which are of considerable value to commercial fisheries and therefore important to human food security.
Fisheries by Catch
Worldwide, hundreds of thousands of sea turtles a year are accidentally caught in shrimp trawl nets, on long line hooks and in fishing gillnets. Sea turtles need to reach the surface to breathe, and therefore many drown once caught. Known as by-catch, it is a serious hazard for green turtles. As fishing activity expands, this threat is more of a problem.
Habitat Loss
Sea turtles are also dependent on beaches for nesting.
- Uncontrolled coastal development, vehicle traffic on beaches, and other human activities have directly destroyed or disturbed sea turtle nesting beaches around the world.
- Green turtle feeding grounds such as sea grass beds are also at risk from coastal development onshore, which leads to pollution and sedimentation in the nearby waters.
- Worldwide, the green turtle continues to be hunted and its eggs harvested. Much of that is for human consumption, but trade of turtle parts remains a profitable business. Tens of thousands of green turtles are harvested each year, particularly in parts of Asia and the Western Pacific.
- Along the Eastern Pacific coast of Mexico, despite complete protection, green turtles are still at risk from exploitation.
- In West Africa, sea turtles are killed for use in medicine and some traditional ceremonies.
Relating it to climate change
Because sea turtles use both marine and terrestrial habitats during their life cycles, the affects of climate change are likely to have a devastating impact on these endangered species.
- Warmer ocean temperatures are also likely to negatively impact food resources for sea turtles, and virtually all marine species.
- Coral reefs, which are an important food source for sea turtles, are in great danger. Almost half of the coral reef ecosystems in the U.S. are in poor or fair condition.
- As a result of rising temperatures, coral reefs are suffering from a "bleaching" effect that kills off parts of the reef.