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701 - 725 of 1229 Items << < 24 25 26 27 28 29 30 31 32 33 > >>
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Concern over the incidental catch of non-targeted species in commercial and
recreational fisheries has greatly increased. Public attention, negative publicity,
controversies between differing fisheries and gear groups and the reauthorization of...
1999-03-31 (iso8601)
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Over recent decades, the marine ecosystems of Prince William Sound (PWS), Alaska have experienced the concurrent effects of a major anthropogenic disturbance, the 1989 Exxon Valdez oil spill (EVOS), and a dynamic atmospheric-oceanic environment....
2014-06-10 (iso8601)
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Diseases caused by parasites are recognized as significant sources of mortality in wild fish populations. I assessed the impacts of multispecies parasitism on a threatened stock of juvenile coho salmon (Oncorhynchus kisutch). A crucial...
2011-01-04 (iso8601)
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Several streams in the mixed conifer cover type of the Ochoco and Blue Mountains of central Oregon were studied to determine what effects selective harvesting of the riparian timber stand had on the amounts and distribution of coarse woody debris...
1990-11-16 (iso8601)
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This study was conducted to show the effects of sand and coarser sediments on the distribution and abundance of insects in Emerald Creek and the Middle Fork of the St. Maries River. Stream profile, substrate conditions, water chemistry and benthos...
1971-09-01
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Two approaches to improving wood treatability include the modification of pressure
schedules during conventional liquid treatments and the use of supercritical fluids (SCFs). In
both of these techniques, pressure differences are important for...
1999-09-27 (iso8601)
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More than 280 species of caddisflies (Trichoptera), representing 80
genera in 16 families, are known to occur in Oregon. Detailed distribution
records within the state are given, as well as the known geographic range
for each species. Biological...
1976-11 (iso8601)
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Sixteen understory plant communities in the riparian zones of small streams are identified and described. They range from pioneer communities on gravel and rock to well-developed shrub communities on flood
plains and terraces. Several other...
1979 (iso8601)
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Aquatic ecological investigation is expanding to encompass considerations of
multiple scales across large landscapes. Much of the analysis included in this work
focuses specifically on coho salmon (Oncorhynchus kisutch) in multiple subbasins on...
2007-11-26T20:53:33Z (iso8601)
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A theory of the origin and distribution of fishes in the Harney Basin is presented. Blitzen River, the hydrographically and ecologically isolated creeks, and the upland tributaries of Silvies River all contain populations derived from the basin's...
1969-03-21 (iso8601)
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Rhabdocoels of the genus Paravortex are parasites of marine
molluscs. The bent-nosed clams, Macoma nasuta(Conrad, 1837) of
Yaquina Bay, Lincoln County, Oregon are commonly infected with a new
species of Paravortex. The morphology of the adult worm...
1969-12-11 (iso8601)
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First introduced to the USA in 1958, Myxobolus cerebralis, the parasite responsible for whirling disease in salmonids, has since spread across the country causing severe declines in wild trout populations in the intermountain west. Recent...
2007-01-23T21:53:48Z (iso8601)
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The quantification and description of sea surface temperature (SST) is critically important because it can influence the distribution, migration, and invasion of marine species; furthermore, SSTs are expected to be affected by climate change....
2012-03-12 (iso8601)
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Conductivity-temperature-depth surveys during 1988 encountered strong baroclinic jets that were evident in
acoustic Doppler current profiler and hydrographic data. During June and July 1988 a filament with high surface
nitrate, high chlorophyll,...
1991-08-15 (iso8601)
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The Mariana Swiftlet (Aerodramus bartschi) (Aves: Apodidae) is endemic to the Mariana Islands, where it currently occurs on Saipan, Aguiguan, and Guam. An introduced population of Mariana Swiftlets is also present on O'ahu in the Hawaiian Islands....
2015-06-18 (iso8601)
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Greater Sage-grouse (Centrocercus urophasianus) habitat research has historically focused on fine-scale (0.007 - 0.032 ha) vegetation structure and composition immediately surrounding sites selected by birds. However, little work has evaluated...
2009-04-13T18:32:42Z (iso8601)
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The U.S. Geological Survey (USGS), in cooperation with Tooele County; Utah Department of Natural Resources, Division
of Water Rights; and Lake Point Improvement District investigated of the ground-water hydrology of Lake Point to provide knowledge...
2024-09-21
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Plant succession is among the fundamental concepts in ecology. Studies addressing plant recruitment, successional mechanisms, and the role of root-colonizing fungi with focus on dark-septate endophytes (DSE) were
conducted in the laboratory and on...
1998-03-16 (iso8601)
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This study was undertaken to determine the effects of rotenone applied during a fish control operation in September 1962 and the installation of Flaming Gorge Dam in November 1962 upon the distribution of invertebrates in the Green River. Since...
1967-05-01
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Reintroduction of wolves to Yellowstone National Park (YNP) in 1995-96 provided a rare opportunity to observe the response of an ecosystem to the return of a top predator, including possible reversal of decades of decline of aspen, cottonwood, and...
2013-05-30 (iso8601)
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Water temperature influenced interactions between redside
shiners and juvenile steelhead trout (≥1+) in the field and the
laboratory. Distribution of the two species within various habitats
was determined in three streams with different water...
1984-11-27 (iso8601)
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A study conducted May 1978-December 1980 determined that the present geographic range of Columbian white-tailed deer, Odocoileus virginianus leucurus, (CWTD) in Douglas County, Oregon encompassed 1199km2. The area was predominately a Quercus...
1981-09-11 (iso8601)
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