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The Finger Lakes Habitat Rehabilitation and Enhancement Project(HREP) is intended to improve winter habitat conditions for fish in a series of interconnected backwater lakes of the Mississippi River near Alma, Wisconsin. Winter habitat requirements (temperature, flow velocity, and dissolved oxygen) for the target fish population in the Finger Lakes have been defined and limnologcal efforts have been aimed at quantifying the spatial-temporal patterns and interrelationships among water movement, oxygen, and temperature. The progress to date (pre-construction) has included detailed investigations into (1) system hydrology (including dye-tracer studies), (2) oxygen supply and depletion, (3) temperature regime, (4) aquatic...
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Widespread decline of Vallisneria americana Michx. and other submersed aquatic species occurred in portions of the Upper Mississippi River System (UMRS) during 1988 1991. These declines prompted study efforts by the LTRMP to better understand factors potentially contributing to the declines. One likely factor limiting growth is nitrogen (N) availability. In order to sustain plant growth over time, N supplies to the sediments need to be replenished as they become depleted due to plant uptake and diffusional losses. During periods of prolonged low flow hydraulic conditions, the availability of N in backwaters of the UMR may limit the productivity of Vallisneria and other species of rooted macrophytes. In this study,...
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The Finger Lakes Habitat Rehabilitation and Enhancement Project (HREP) is intended to improve winter habitat conditions for fish in a series of interconnected backwater lakes of the Mississippi River near Alma, Wisconsin. Winter habitat requirements (temperature, flow velocity, and dissolved oxygen) for the target fish population in the Finger Lakes have been defined and limnological efforts have been aimed at quantifying the spatial-temporal patterns and interrelationships among water movement, oxygen, and temperature. The progress to date (preconstruction) has included detailed investigations into (1) system hydrology (including dye-tracer studies), (2) oxygen supply and depletion, (3) temperature regime, (4)...
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(a) Invasions and declines of submersed macrophyte communities have been reported worldwide. In general, factors contributing to invasions are most poorly understood. Factors potentially contributing to macrophte declines are numerous, and include reduced irradiance, nutrient depletion, parasites and pathogens, toxin accumulation, animal damage, climatic fluctuations, and other factors. Attention to these dynamics in submersed macrophyte communities is of more than academic interest, since coordination of macrophyte management policies and procedures with natural controls could improve the efficiency of macrophyte management efforts. Indeed, there is some evidence that intense management may prolong the dominance...
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This report embodies a review describing the potential impacts on aquatic vegetation from waves generated by commercial and recreational vessel traffic, and contrasts these impacts with effects of natural forces. The review was undertaken as part of a Corps of Engineers study on navigation impacts on the Upper Mississippi River. Interactions between waves and aquatic vegetation are summarized in the report. Waves act directly by uprooting or fragmenting plants. Wave action can resuspend and transport sediments, resulting in altered sediment texture and sediment resuspension. Changes in sediment texture potentially affect plant nutrition. Resuspended sediments can limit plant photosynthesis, due to reduced availability...
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