( əkì´´nōdûr'mətə ) [Gr.,=spiny skin], phylum of exclusively marine bottom-dwelling invertebrates having external skeletons of calcareous plates just
an older instrumentation system for indirectly determining ocean floor depth. Echo sounding is based on the principle that water is an excellent
common name for any fish in the order Anguilliformes, and characterized by a long snakelike body covered with minute scales embedded in the skin. Eels
or sea elephant, a true seal of the genus Mirounga. It is the largest of the fin-footed mammals, or pinnipeds, exceeding the walrus in size. There is
Marked warming of the eastern Pacific Ocean that occurs when a warm current of water moves from the western Pacific, temporarily replacing the cold
any plant or animal species whose ability to survive and reproduce has been jeopardized by human activities. In 1999 the U.S. government, in
ESTUARIES ARE KNOWN by many different names: bays, coves, inlets, harbors, sounds, and lagoons. Simply put, they are places where rivers meet the sea.
( yutrō´´fĭkā'shən ), aging of a lake by biological enrichment of its water. In a young lake the water is cold and clear, supporting little life. With