부산대학교 도서관

A sound-scattering layer, composed of discrete hyperbolic echosequences and apparently restricted to the Slope Water region of the western North Atlantic, has been identified from the Deep Submergence Research Vehicle Alvinwith schools of the myctophid fish Ceratoscopelus maderensis. By diving into the layer and using Alvin'secho-ranging sonar, we approached and visually identified the sound scatterers. The number of echo sequences observed with the surface echo-sounder (1/23.76 × 105cubic meters of water) checked roughly with the number of sonar targets observed from the submarine (1/7.45 × 105cubic meters). The fish schools appeared to be 5 to 10 meters thick, 10 to 100 meters in diameter, and on centers 100 to 200 meters apart. Density within schools was estimated at 10 to 15 fish per cubic meter.