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Biomedical subjects

J M Teal

Publications and source records attributed to J M Teal.

9 recordsLinked to original sources

Polychlorobiphenyls in North Atlantic ocean water.

Concentrations of polychlorobiphenyls (PCB's) have been measured at the surface and at various depths in the water of the North Atlantic Ocean between 26 degrees N and 63 degrees N. The concentrations average about 20 parts per trillion and amount to an estimated 2 x 10(4) metric tons of PCB's in the upper 200 meters of water. The average concentrations of PCB's in the surface water of the Sargasso Sea are lower than those in the northern North Atlantic.

Polychlorinated Biphenyls

Ceratoscopelus maderensis: peculiar sound-scattering layer identified with this myctophid fish.

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 Alvin with schools of the meyctophid fish Ceratoscopelus maderensis. By diving into the layer and using Alvin's echo-ranging sonar, we approached and visually identified the sound scatterers. The number of echo sequences observed with the surface echo-soutnder (1/23.76 x 10(5) cubic meters of water) checked roughly with the number of sonar targets observed from the submarine (1/7.45 x 105 cubic 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.

Animals