Читать книгу Oceans For Dummies - Joseph Kraynak - Страница 92

One of the simplest ways to section off the ocean is to divide it into top and bottom — the top being the pelagic zone (nearly all the water), and the bottom being the benthic zone (consisting of a relatively thin layer of water above the seafloor, the seafloor itself, sediment, and some subsurface layers).

Organisms may be classified as either pelagic or benthic. Pelagic organisms inhabit the open sea and surface of the ocean, whereas benthic organisms hug the bottom. Species like corals, seagrasses, mollusks (oysters, mussels and the like), crustaceans (crabs, barnacles, and so forth), and fish like rays and flounder are benthic; basically anything that’s attached to the bottom or spends most of its life crawling or swimming along the bottom is considered benthic. All other organisms that float or swim are pelagic.