Publications

We studied methylmercury (MeHg) and total mercury (HgT) in impounded and natural surface waters in northwestern Minnesota, in settings ranging from agricultural to undeveloped. In a recently constructed (1995) permanent-pool impoundment, MeHg levels typically increased from inflow to outflow during 1997; this trend broke down from late 1998 to early 1999. MeHg levels in the outflow...

The Grand Portage Reservation is located in northeastern Cook County, Minnesota at the boundary between Minnesota, USA, and Ontario, Canada. Between 1991 and 2000 the U.S. Geological Survey conducted a series of studies, with the cooperation with Grand Portage Band of Chippewa, to describe the water resources of the Grand Portage Reservation. Ground water moves primarily through...

The U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources, conducted a study to characterize ground-water flow conditions between the Canisteo Mine Pit, Bovey, Minnesota, and surrounding aquifers following mine abandonment. The objective of the study was to estimate the amount of steady-state, ground-water flow between the Canisteo Mine Pit and...

Detroit River is a connecting channel on the Great Lakes waterway that joins Lake St. Clair with Lake Erie. The river forms part of the international boundary between the United States and Canada in southeastern Michigan and southern Ontario. Drifting buoys were deployed on Detroit River to help investigate flow characteristics of four selected reaches as part of a source water...

Lake sturgeon Acipenser fluvescens, which are now protected from harvest, are considered rare in the upper Mississippi River and little information is available on the remaining populations. Transmitters were implanted into 31 lake sturgeon from two sites in the upper Mississippi River to describe their habitats and movement. The areas surrounding the tagging sites were core areas for...

The objectives of this study are to provide continuous discharge records for selected rivers at specific sites to supply the needs for regulation, analytical studies, definition of statistical properties, trends analysis, determination of the occurrence, and distribution of water in streams for planning. The project is also designed to determine lake levels and to provide discharge for...

Recharge to unconfined aquifers in the seven-county Twin Cities metropolitan area of Minnesota was estimated by five methods. Mean recharge estimated as a percentage (27 percent) of precipitation ranged from 7.7 to 8.3 in./yr across the study area. The median recharge estimated from automated analyses of streamflow-recession displacements for seven basins ranged from 1.2 to 12.2 in./yr...

The selective sea lamprey (Petromyzon marinus) larvicide 3-trifluoromethyl-4-nitrophenol (TFM) is currently used to control parasitic sea lampreys in tributaries to the Great Lakes basin. The concentration and persistence of TFM and its major metabolite, TFM glucuronide (TFM-glu), was determined in fillet tissue of fish after a typical stream application. Rainbow trout (Oncorhynchus...

Water resources data for the 2001 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 quality of ground-water wells. This report contains discharge records for 157 streamflow-gaging stations; stage only records for 2 stream-gaging stations and 25 lake-gaging stations; stage...

One of the early tenets of conservation biology is that population viability is enhanced by maintaining multiple populations of a species. The strength of this tenet is justified by principles of bet-hedging. Management strategies that reduce variance in population size will also reduce risk of extinction. Asynchrony in population fluctuations in independent populations reduces variance...

An analytic element ground-water-flow model was constructed to help understand the ground- and surface-water hydrology in the vicinity of Dead Pike Lake and Powell Marsh, Vilas County, Wisconsin. The model was used to simulate the effect of removing Powell Marsh control structures (ditches and Vista Pond) on the hydrology of Dead Pike Lake. Measurements and model simulation results show...

Apparent worldwide declines in amphibian populations (Pechmann and Wake 1997) have stimulated interest in amphibians as bioindicators of the health of ecosystems. Because we have little information on the population status of many species, there is interest by public and private land management agencies in monitoring amphibian populations. Amphibian egg and larval surveys are established...