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Full-Text Articles in Life Sciences
Impacts Of Eutrophication On Benthic Invertebrates & Fish Prey Of Birds In Farmington And Bear River Bays Of Great Salt Lake, Trip Armstrong, Wayne A. Wurtsbaugh
Impacts Of Eutrophication On Benthic Invertebrates & Fish Prey Of Birds In Farmington And Bear River Bays Of Great Salt Lake, Trip Armstrong, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
Farmington Bay’s watershed is primarily in the heavily populated metropolitan Salt Lake City, and consequently, it receives approximately 50% of its inflow from nutrient‐ rich wastewater releases. The high nutrient loads make it eutrophic and reducing the loading has been suggested to reduce blooms of toxic cyanobacteria. However, the bay also supports thousands of wading birds and waterfowl, and there is concern that reducing nutrient inflows might reduce the production of bottom‐dwelling insects and other invertebrates that the birds rely upon.
Evaluating The Effectiveness Of Grassbed Treatments As Habitat For Juvenile Black Bass In A Drawdown Reservoir, D. R. Ratcliff, Wayne A. Wurtsbaugh, J. Zustak
Evaluating The Effectiveness Of Grassbed Treatments As Habitat For Juvenile Black Bass In A Drawdown Reservoir, D. R. Ratcliff, Wayne A. Wurtsbaugh, J. Zustak
Watershed Sciences Faculty Publications
Many reservoirs in arid regions experience highly variable water levels caused by seasonal inflow fluctuations and designated outflow requirements. At Shasta Lake, California, managers plant cereal-grain grassbeds on exposed drawdown shorelines to increase juvenile fish habitat, localize productivity, and increase invertebrate fish prey. To determine the efficacy of these plantings, the abundance of juvenile black basses Micropterus spp. (20–55 mm standard length) and the amount of periphyton and macroinvertebrate prey were compared among three treatment types: (1) planted grassbeds of cereal barley Hordeum vulgare; (2) artificial rope grassbeds, which eliminated physical deterioration and nutrient release; and (3) nonplanted control sites …
Hydroacoustic Assessment Of Abundance And Diel Distribution Of Sockeye Salmon And Kokanee In The Sawtooth Valley Lakes, Idaho, D. Beauchamp, Chris Luecke, Wayne A. Wurtsbaugh, H. G. Gross, Phaedra E. Budy, S. Spaulding, R. Dilenger, C. P. Gubala
Hydroacoustic Assessment Of Abundance And Diel Distribution Of Sockeye Salmon And Kokanee In The Sawtooth Valley Lakes, Idaho, D. Beauchamp, Chris Luecke, Wayne A. Wurtsbaugh, H. G. Gross, Phaedra E. Budy, S. Spaulding, R. Dilenger, C. P. Gubala
Watershed Sciences Faculty Publications
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 Oncorhynchus nerka) in Sawtooth Valley lakes of Idaho during September 1991 and 1992. Abundance of O. nerka varied among the four lakes containing this species (12,500–257,000) and varied between years in Redfish Lake (86,400 in 1994 and 241,000 in 1992) and Alturas Lake (230,000 in 1991 and 257,000 in 1992). In Alturas Lake, where piscivore densities were high and zooplankton densities were low, small acoustic targets (≤18 cm …
Effects Of Moonlight And Daylight On Hydroacoustic Estimates Of Pelagic Fish Abundance, Chris Luecke, Wayne A. Wurtsbaugh
Effects Of Moonlight And Daylight On Hydroacoustic Estimates Of Pelagic Fish Abundance, Chris Luecke, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
To determine how moonlight and daylight affect hydroacoustic estimates of fish abundance, we used a dual-beam transducer and echo integration to survey pelagic fish (primarily Bonneville ciscoes Prosopium gemmifer) in Bear Lake, Utah and Idaho. During the new moon, the fish were dispersed (not schooling) below the thermocline, chiefly at the depths of 10–20 m. At full moon, they were dispersed but much closer to the bottom, where they were difficult to detect. Acoustic estimates offish density and biomass during full moons were approximately 50% of values derived during new moons. A diel survey during a new moon indicated that …