Invisible Fences. Route Sea Fauna

Press, Volume XCIX, Issue 29240, 25 June 1960, Page 10

Invisible Fences. Route Sea Fauna

[By ROBERT C. COWEN, Natural Science Editor of the "Christian Science Monitor." Published by arrangement]

the sea has few obvious barriers to their movements, many of its creatures are confined by invisible fences. Adapted to a narrow range of temperture and of salinity, such creatures must' stay within water masses whose characteristics meet their special needs.

BeCause Of this, oceanographers often can' trace surface circulations by following the movements of certain organisms, identifying drifting water masses by their characteristic plankton. “Plankton” is the technical term for tiny plants and animals whose swimming powers are so weak they are “made to wander” with the water movements in the literal meaning of this Greek word. In like manner, oceanographers hope to be able to trace water patterns in the depths from the distribution of characteristic organisms found there. The Scripps Institute of Oceanography at La Jolla, California, is sending its research ship Spencer F. Baird pn a midPacific expedition to gather data that should help marine biologists work out methods of doing this. As reported in the magazine “Science,” the ship will explore an area of the central equatorial Pacific between Hawaii and California. Water samples and temperatures will be taken at various depths, some samples of bottom sediments will be brought up, and nets will be towed to catch deep-water plankton and other creatures. By correlating these data with what is already known, biologists may be able to confirm whether or not deep-living organisms are limited enough by physical and chemical conditions so that their occurrence is a good indication of various water types. Then, by tracing the distribution of these animals, they may be able to trace circulation patterns in the depths. The bottom samples will be taken as cores punched out by long tubes weighted to penetrate several feet into the sediments. These will be collected intensively

in a region south of Hawaii. Cores taken there in 1875 by the British Challenger Expedition, the first world-girdling oceanographic survey, and in 1950 by Scripps “Mid-Pacific” expedition indicate that ' sediments dating back to Lower Tertiary times, 40,000,000 to 70,000,000 years ago, are outcropping on the sea bed. The Baird’s geologists will punch out about 60 cores which will be studied to find ' out. if possible, under what conditions the ancient sediments are exposed Among other things, this could shed light on processes moving sediments -about in the area. Meanwhile, Scripps scientists are planning an expedition to one of the least-known parts of the earth’s surface, the Indian Ocean. Called “Monsoon,” it is scheduled for the period from August, 1960, to February, 1961. Although the expedition will take data from parts of the southwestern Pacific, the southern and central Indian Ocean will be a major area of its mission.