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551 - 575 of 1229 Items << < 18 19 20 21 22 23 24 25 26 27 > >>
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Zooplankton were collected from adjacent littoral and limnetic sites in Lake Mead, Nevada-Arizona, USA. Limnetic species dominated both littoral and limnetic zooplankton communities; littoral species rarely exceeded 2% of monthly total zooplankton...
1991-01-01
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Age-0 pollock are the most abundant small pelagic species around the Pribilof Archipelago, composing more than 90% of both the local numerical abundance and the fish biomass abundance. Due to a favorable combination of physical and biological...
2002 (iso8601)
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We used dual-beam hydroacoustics and echo integration techniques, combined with midwater trawling and gillnetting, to assess the abundance and distribution of the endangered Snake River juvenile sockeye salmon and resident kokanee (both...
1997-01-01
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Contaminant transport in hydrogeologic systems requires knowledge of transmissivity, storage coefficient, and dispersivity. Techniques for evaluating transmissivity and storage coefficient under field conditions are well known. However, the...
2007-12-04
2007-12-04 1981-03-01 |
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Contaminant transport in hydrogeologic systems requires knowledge of transmissivity, storage coefficient, and dispersivity. Techniques for evaluating transmissivity and storage coefficient under field conditions are well known. However, the...
2007-12-04
2007-12-04 1981-03-01 |
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We used dual-beam hydroacoustics and echo integration techniques, combined with midwater trawling and gillnetting, to assess the abundance and distribution of the endangered Snake River juvenile sockeye salmon and resident kokanee (both...
1997-01-01
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Methodological difficulties, particularly when multifleet-multispecies fisheries are active, explain pro parte a weak research effort on the socio-economic impact of fishery activities after the implementation of a marine protected area. Two...
2010 (iso8601)
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Understanding seasonal migration and localized persistence of populations is critical for effective species harvest and conservation management. Pacific salmon (genus Oncorhynchus) forecasting models predict stock composition, abundance, and...
2015-07-22 (iso8601)
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CONTENTS THE WATER RESOURCES COMMISSION AND DEPARTMENT 1c "To serve the public by practicing and promoting wise long-term water management. " 1.¨REGON WATER LAWS 22 water management in Oregon 2.°ATER PROTECTIONS AND RESTRICTIONS 262011 managing...
2024-09-21
2005-05-19 2005-03-15 |
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We examined the influence of biotic and abiotic factors on the distribution, abundance, and condition of salmonid fishes along a stream gradient. We observed a longitudinal change in fish distribution with native cutthroat trout, Oncorhynchus...
2005-01-01
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The contribution of emissions from agricultural facilities is rapidly becoming a major concern for local and regional air quality. Characterization of particle properties such as physical size distribution and chemical composition can be valuable...
2008-05-07
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Relative to extensive research on the freshwater stages of steelhead Oncorhynchus mykiss life history, little is
known about the species’ estuarine and early marine phases despite the decline of numerous populations, including
several from the...
2014-04-15 (iso8601)
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Non-native invasive plant species can often have negative effects on native ecosystems, such as altered nutrient cycling, decreased habitat for wildlife, and outcompeting native plants. Around the Great Salt Lake (GSL), Utah, the invasive wetland...
2014-05-01
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Chinook salmon, Oncorhynchus tshawytscha, returning to the Yukon River basin and other large river systems in western Alaska have declined dramatically since the late 1990s. This continuing trend has raised concerns over the future status of the...
2013-08-01 (iso8601)
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Acidity distribution within any given soil profile is dependent on
mineralogical make-up of the parent material as well as environmental conditions prevalent during the weathering history of the soil.
An experiment was designed to study the...
1968-08-01 (iso8601)
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The Umpqua River estuary was seined and gilinetted during the summer of
1972 to estimate the composition and distribution of fishes. The number of
species collected at most sites averaged from four to six per seine haul
and was relatively constant...
1977-04 (iso8601)
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Individual fishing quota (IFQ) systems are typically expected to increase the profitability of a fishery and improve sustainability by ensuring catches remain within quotas. They can also have important distributional and ecological implications...
2014-07-07 (iso8601)
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An ecological study of the benthic and fish communities at Mokapu, O'ahu, was completed in the summer of 1978 approximately 1 yr subsequent to the installation of a submarine outfall by the City and County of Honolulu. Data were obtained from five...
2008-07-10
2008-07-10 1979-02-01 |
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Mediterranean populations of loggerhead Caretta caretta and green sea turtles Chelonia mydas are subject to several anthropogenic threats, with documented mortality from incidental capture in fishing gear. However, how such mortalities actually...
2016 (iso8601)
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We are conducting studies on the impacts of parasites on Oregon coastal coho salmon (Oncorhynchus kistuch). An essential first step is documenting the geographic distribution of infections, which may be accomplished by using different methods for...
2011-12 (iso8601)
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1. Despite their importance in determining the rate of both energy gain and expenditure, how
the fine-scale kinematics of foraging are modified in response to changes in prey abundance
and distribution remain poorly understood in many animal...
2015-07 (iso8601)
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ill.; Includes bibliographic references (p. 144-155); Cooperative Agreement CA-9000-3-0003 Subagreement 12; CPSU/OSU 88-3.
1988-09-21
2009-03-20 2009-04-27 |
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A study of the host range and distribution of ticks and chiggers
(Acari) was undertaken in two contrasting forested areas of western
Oregon. Acarines were sampled from host mammals which were
trapped along line transects laid out in both areas,...
1972-08-09 (iso8601)
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To best manage Eagle Creek National Fish Hatchery, negative interactions between hatchery salmonids and Endangered Species Act listed wild salmonids in the Eagle Creek Basin need to be minimized. Our objectives were: 1) to compare summer rearing...
2012-09-28 (iso8601)
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