VOA科学技术2024--Scientists Map Largest Deep-Sea Coral Reef off US Atlantic Coast（在线收听）

Scientists Map Largest Deep-Sea Coral Reef off US Atlantic Coast

　　Scientists have mapped the largest coral reef off America's Atlantic coast.

　　Researchers say the reef stretches about 500 kilometers from Florida to South Carolina. At some points, it is 109 kilometers wide. The researchers measured the reef using 3D mapping technology.

　　"It's eye-opening – it's breathtaking in scale," Stuart Sandin told The Associated Press. He is a marine biologist at the Scripps Institution of Oceanography. Sandin was not included in the research.

　　Ocean scientists have known since the 1960s that some coral life was present off the Atlantic Coast. But the reef's exact size had remained a mystery. New underwater mapping technology made it possible to construct images of the ocean floor in three dimensions.

　　The largest yet known deep coral reef "has been right under our noses, waiting to be discovered," said Derek Sowers. He is an oceanographer at the nonprofit group Ocean Exploration Trust.

　　Sowers and other scientists recently released maps of the reef in the publication Geomatics.

　　The reef was found at ocean depths from 200 to 1,000 meters. Deep-sea life cannot use sunlight to carry out photosynthesis. Instead, reef corals at extreme depths must filter food particles out of the water for energy.

　　Deep coral reefs are known to contain animals such as sharks, swordfish, sea stars, octopus, shrimp and many kinds of fish.

　　Unlike deep coral reefs, tropical reefs are better known to scientists and sea explorers alike because they are easier to reach. The world's largest tropical coral reef system, Australia's Great Barrier Reef, stretches for 2,300 kilometers.

　　Sowers said it is possible larger deep-sea reefs will be discovered in the future since only about 25 percent of the world's ocean floor has been mapped in 3D. Only 50 percent of U.S. offshore waters have been mapped. Maps of the ocean floor are created using high-technology sound equipment, called sonar, on ships.

　　Erik Cordes is a marine biologist at Temple University and a co-writer of a study on the mapping operation. He said deep reefs cover more of the ocean floor than tropical reefs. But both are currently facing similar risks, including climate change and damage from oil and gas exploration activities

　　Words in This Story

　　coral – n. a hard, usually pink or white substance produced by a type of small sea animal

　　reef – n. a collection of rocks or sand that sits below the surface of the ocean

　　3D (three dimensional) –adj. showing the height, width and length of something rather than just two dimensions

　　scale – n. the size or level of something

　　photosynthesis – n. the process by which a plant uses carbon dioxide from the air, water from the ground, and the energy from the light of the sun to produce its own food and oxygen

　　filter – v. to pass a substance through a piece of equipment in order to remove solid pieces or other substances