993 resultados para Naval Research Laboratory (U.S.)
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A 0.25 m**2 United States Naval Electronics Laboratory box corer was used to take replicate samples from an oligotrophic bottom under the North Pacific Central Water Mass (~28°N, 155°W). The bottom is a red clay with manganese nodules at a depth of 5500-5800 m. Macrofaunal density ranges from 84 to 160 individuals per m**2 and is therefore much the same as in Northwest Atlantic Gyre waters. Of the macrofaunal taxa, polychaetes dominate (55 %), followed by tanaids (18 %), bivalves (7 %), and isopods (6 %). Meiofaunal taxa were only partially retained by the 297 µm screen used in washing. Even then, they are 1.5-3.9 times as abundant as the macrofaunal taxa, with nematodes being numerically dominant by far. Foraminifera seem to comprise an important portion of the community, but could not be assessed accurately because of the inability to discriminate living and dead tests. Remains of what are probably xenophyophoridans are also very important, but offer the same problem. Faunal diversity is extremely high, with deposit feeders comprising the overwhelming majority. Most species are rare, being encountered only once. The distributions of only three species show any significant deviation from randomness. The polychaete fauna from box cores collected from 90 miles to the north was not significantly different from that of the principal study locality. Concordance appeared at several taxonomic levels, from species through macrofaunal/meiofaunal relationships. As a result, the variation in total animal abundance shows aggregation among cores. We discuss Sokolova's concept of a deep-sea oligotrophic zone dominated by suspension feeders, and reconcile it with our present findings. The high diversity of the fauna combined with the low food level contradict theories that relate diversity directly with productivity.
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On Vermilion Sea Expedition two research vessels among which the R/V Spencer F. Baird conducted a geological and geophysical exploration of the Gulf of California from February to May, 1959. Support was obtained from the Office of Naval Research and the Bureau of Ships of the U. S. Navy and from a grant of the American Petroleum Institute. Study of the canyons was one feature of the first part of the expedition. Submarine canyon studies were directed by Francis P. Shepard, Professor of Submarine Geology, aboard the research vessel Spencer F. Baird. The expedition found that the narrow channel between Angel de la Guarda Island, toward the head of the Gulf, and the peninsula is scoured almost free of sediments by strong currents. On the other side of Angel de la Guarda Island, between it and the mainland, one of the dredge hauls brought up a manganese nodule. It came from a depth of approximately 1500 feet. This is the shallowest water in which the nodules have been found. Studies have been under way some time on the feasibility of mining such nodules from the sea floor. They contain cobalt, nickel, copper and other valuable metals. (also in, Scripps Institution of Oceanography Vermilion Sea Expedition to the Gulf of California, http://library.ucsd.edu/dc/object/bb34484017)
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Issued August 1977.
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Includes indexes.
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"October 1980."
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"October 1981."
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In October 1980 the U.S. Army Corps of Engineers conducted a beach nourishment project at the Lexington (Michigan) Harbor on the southwest shore of Lake Huron, a project designed to mitigate beach erosion attributable to the installation of the harbor. In response to a request from the Coastal Engineering Research Center (CERC), the U.S. Fish and Wildlife Service's Great Lakes Fishery Laboratory conducted a Corps-funded study from June 1980 to October 1981 along a 8.4-kilometer segment of shoreline adjacent to the harbor to determine the effect of the Corps' beach nourishment project on the nearshore aquatic environment. The study performed by the service included aerial photographic surveys of the study area; measurement of dissolved oxygen, turbidity, and suspended particulate matter levels; and collection of lake bottom sediments, macrozoobenthos and fish. Analysis of the aerial photographs showed that the beach face profile changed markedly during the study as a result of beach nourishment. Dredging of about 19,000 cubic meters of beach sediment from an accretion area adjacent to the harbor's north breakwater caused the beach face to recede, while deposition of this sediment on a feeder beach south of the harbor caused the beach face there to extend lakeward.
An assessment of ozone and chlorine dioxide technologies for treatment of municipal water supplies /
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Mode of access: Internet.
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Co-sponsored in cooperation with the Dept. of Fisheries and Wildlife, Oregon State University.
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Mode of access: Internet.
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"Contract no. 68-03-2649."
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Mode of access: Internet.
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Mode of access: Internet.