Publications

Data that describe the physical characteristics of stream subbasins upstream from selected points on streams in the Cottonwood River Basin, located in southwestern Minnesota, are presented in this report. The physical characteristics are the drainage area of the subbasin, the percentage area of the subbasin covered only by lakes, the percentage area of the subbasin covered by both lakes...

Three aquifers and two confining units have been delineated within the drift underlying the area near the site of a former coal-tar distillation and wood-preserving plant in St. Louis Park, Minnesota. The hydrogeologic units of the drift, in descending order, are the upper drift aquifer, the upper drift confining unit, the middle drift aquifer, the lower drift confining unit. and the...

Vallisneria americana declined in backwaters of the Upper Mississippi River, U.S.A., after a drought in 1988. To determine whether viable seeds of V. americana occurred in the seed bank of navigation pool 7, Lake Onalaska, the upper 5 cm of sediment was collected from 103 sites in May 1990. These sediment samples were kept in pots at a depth of 0.4, 0.8, and 1.2 m in an outdoor pond for...

Severe sedimentation since lock and dam construction in the 1930s has reduced water depth in Upper and Lower Brownˈs lakes, a backwater complex in Pool 13 of the upper Mississippi River, and resulted in periods of chronic anoxia. This backwater complex was rehabilitated by construction of a deflection levee, installation of a water control structure, and excavation of canals through the...

Computer models can be powerful tools for addressing many problems in fishery management, but uncertainty about how to apply models and how they should perform can lead to a cautious approach to modeling. Within this approach, we expect models to make quantitative predictions but only after all model inputs have been estimated from empirical data and after the model has been tested for...

Available data on the ecology of aquatic organisms in the Red River of the North Basin, a study unit of the U.S. Geological Survey's National Water-Quality Assessment program, were collated from numerous sources. Lack of information for invertebrates and algae precluded a general summary of distribution and ecology throughout the basin. Data on fish species distributions in the major...

The Western Lake Michigan Drainages (WMIC) study unit, under investigation since 1991, drains 20,000 square miles (mi2) in eastern Wisconsin and Upper Michigan (fig. 1). The major water-quality issues in the WMIC study unit are: (1) nonpoint-source contamination of surface and ground water by agricultural chemicals, (2) contamination in bottom sediments of rivers and harbors by toxic...

Ground-water baseflow to six subreaches of the Upper Mississippi River were estimated for July 1988, a period of drought. Ground-water baseflow to each subreach was estimated on the basis of streamflow gains determined from records of daily discharge at gaging stations. Streamflow gains were adjusted for estimated inflow from tributaries, municipal and industrial discharges, withdrawals...

Age-0 northern pike Esox lucius prefer vegetated habitats that are difficult to sample with standard towed gears. Light traps can be effective for sampling larval fishes in dense vegetation, given positive phototaxis offish. We evaluated the phototactic response of young northern pike by comparing the catches of larvae and juveniles obtained with plexiglass traps deployed with a chemical...

This report presents selected data collected during the first year (December 1993 to September 1994) of a three year water-quality study of surficial-sand aquifers and selected lakes in east Otter Tail County, Minnesota. The objectives of the study are (1) to determine the presence and distribution of nitrate-nitrogen and selected pesticides in ground water from the surficial-sand...

Selected water-quality constituents were determined in water from 5 surface-water sites and 29 wells in Dakota County, Minnesota, to search for possible relations to selected physical factors, including waste-water discharge, agricultural land, Quaternary deposits, bedrock, soil-leaching potential, and water-table depth. All surface-water samples were from the Vermillion River Basin...

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