“Endangered sea turtles”的意思、由来-开放百科全书

Worldwide, hundreds of thousands of sea turtles a year are accidentally caught in shrimp trawl nets, on longline hooks and in fishing gill-nets. Sea turtles need to reach the surface to breathe, and therefore many drown once caught. Loggerhead and hawksbill turtles are particularly vulnerable. Nearly all species of sea turtle are classified as Endangered. They are killed for their eggs, meat, skin and shells. They also face habitat destruction. Climate change has an impact on turtle nesting sites. As fishing activity expands, this threat is more of a problem.

Endangered Species Act

The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) is one of the few dozens of US environmental laws passed in the 1970s, and serves as the enacting legislation to carry out the provisions outlined in The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).[1] Designed to protect critically imperiled species from extinction as a "consequence of economic growth and development untempered by adequate concern and conservation", the ESA was signed into law by President Richard Nixon on December 28, 1973. The U.S. Supreme Court found that "the plain intent of Congress in enacting" the ESA "was to halt and reverse the trend toward species extinction, whatever the cost."[2] The Act is administered by two federal agencies, the United States Fish and Wildlife Service (FWS) and the National Oceanic and Atmospheric Administration (NOAA).

Endangered marine turtles

During Obama’s presidency, 29 species recovered enough to be taken off the endangered species list, more than under all four presidents before him (George H. W. Bush did not delist any species). And 340 were added, far more than under his predecessor, George W. Bush. But the Endangered Species Act itself has changed during the Obama years, and critics say that despite the impressive numbers, it’s actually become more business-friendly and less effective at protecting wildlife.

Hawksbills are named for their narrow, pointed beak. They also have a distinctive pattern of overlapping scales on their shells that form a serrated-look on the edges. These colored and patterned shells make them highly-valuable and commonly sold as "tortoiseshell" in markets.

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.

Loggerhead turtles are named for their large heads that support powerful jaw muscles, allowing them to crush hard-shelled prey like clams and sea urchins. They are less likely to be hunted for their meat or shell compared to other sea turtles. Bycatch, the accidental capture of marine animals in fishing gear, is a serious problem for loggerhead turtles because they frequently come in contact with fisheries.

Threats

Worldwide, hundreds of thousands of sea turtles a year are accidentally caught in shrimp trawl nets, on longline hooks and in fishing gillnets—a threat known as bycatch. Sea turtles need to reach the surface to breathe, and therefore many drown once caught. Loggerheads are highly migratory and are very likely to come in contact with a fishery, particularly in shrimp gillnets and longlines. [2]

Climate change, also called global warming, refers to the rise in average surface temperatures on Earth. An overwhelming scientific consensus maintains that climate change is due primarily to the human use of fossil fuels, which releases carbon dioxide and other greenhouse gases into the air. The gases trap heat within the atmosphere, which can have a range of effects on ecosystems, including rising sea levels, severe weather events, and droughts that render landscapes more susceptible to wildfires.

Overfishing

Human activities have tipped the scales against the survival of these ancient mariners. Nearly all species of sea turtle are classified as Endangered. Slaughtered for their eggs, meat, skin and shells, sea turtles suffer from poaching and over-exploitation. They also face habitat destruction and accidental capture in fishing gear. Climate change has an impact on turtle nesting sites. It alters sand temperatures, which then affects the sex of hatchlings.^[1]

Hawksbills are particularly susceptible to entanglement in gillnets and accidental capture on fishing hooks. Sea turtles need to reach the surface to breathe, and therefore many drown once caught. Known as bycatch, this is a serious threat to hawksbill turtles. As fishing activity expands, this threat is more of a problem.^[2]

References

1. ^{{cite web|url=https://www.worldwildlife.org/species/sea-turtle|title=Sea Turtle - Species - WWF|publisher=}}
2. ^{{cite web|url=https://www.worldwildlife.org/species/hawksbill-turtle|title=Hawksbill Turtle - Sea Turtles - Species - WWF|publisher=}}