Publications

Recruitment failure is considered to be a major factor contributing to the decline of fish populations in soft, acidic waters; direct mortality of embryo-larval fishes has been postulated as a major cause of the decline. Little is understood of the physiological consequences to embryo-larval fishes of prolonged exposure to soft, acidic waters; however, dysfunction of respiratory and...

Burrowing mayflies (Hexagenia bilineata) were analyzed to assess longitudinal patterns in their cadmium and mercury content along the upper Mississippi River. Emergent mayflies (subimagoes and imagoes) were collected in 1988 at 34 sites (25 navigation pools), extending 1260 km from Little Falls, Minnesota, downstream to St. Louis, Missouri. Cadmium concentrations in composite samples of...

Despite a long history of human manipulation, the most dramatic changes in the upper Mississippi River occurred in the 1930s with construction of a lock and dam system to facilitate the commercial transport of commodities. In 1988, barge traffic through the system ranged from 7,500 tows per year at Lock and Dam 26 (near Alton, Illinois) to 1, 118 at Lock and Dam 1 (in Minneapolis/St...

No abstract available.

Concentrations of mercury and zinc in the threeridge mussel Amblema plicata plicata, sampled in 1987 from Pools 3 and 10 in the upper Mississippi River, were comparable to concentrations in mussels from moderately contaminated systems, while copper concentrations were similar to concentrations in mussels from more polluted waters. Cadmium concentrations in mussels were significantly less...

Floatation of eggs in water and specific gravity of eggs of Black-crowned Night-Herons (Nycticorax nycticorax ), Snowy Egrets (Egretta thula ) and Great Egrets (Casmerodius albus ) were evaluated as methods to determine date of hatching. Although specific gravity was a better predictor of hatching date than egg flotation, both techniques were imprecise. The regression between specific...

Recent studies indicate that the density and diversity of freshwater mussels are declining in many large river systems, possibly from low-level chemical contamination. Exposure of Lam-psilis ventricosa (Barnes, 1823) to 0, 22, 111, and 305 μg/L of cadmium for 28 d in a proportional diluter resulted in a significant decrease (p ≤ 0.05) in respiration rate as cadmium concentration...

This report is a compilation of data on surface- and ground-water quality, lake sediment, and lake-level fluctuation collected by the U.S. Geological Survey (USGS) during 1981- 87 on or near the St. Croix Indian Reservation. The purpose of this report is to provide baseline data on selected aspects of the water resources of the St. Croix Indian Reservation as a referenceby which future...

Seventeen methods for estimating ice-affected streamflow are evaluated for potential use with the U.S. Geological Survey streamflow-gaging station network. The methods evaluated were identified by written responses from U.S. Geological Survey field offices and by a comprehensive literature search. The methods selected and techniques used for applying the methods are described in this...

Water resources data for the 1991 water year for Michigan consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and water levels and water temperature of ground water. This report contains discharge records for 146 streamflow-gaging stations; stage only records for 1 river-gaging station and 13 lake-gaging stations; stage and...

This compilation of short papers reports on technical advances in the applied computer sciences. The papers describe computer applications in support of earth science investigations and research. This is the third volume in the series "Selected Papers in the Applied Computer Sciences." Listed below are the topics addressed in the compilation: Integration of geographic information systems...

PROBLEM: Surface-water information is needed for surveillance, planning, design, hazard warning, operation, and management in water-related fields such as water supply, hydroelectric power, flood control, irrigation, bridge and culvert design, wildlife management, pollution abatement, flood-plain management, and water-resources development An appropriate data base is necessary to provide...