Publications

We examined effects of dietary methylmercury (MeHg) on reproduction of fathead minnows (Pimephales promelas). Juvenile fish were fed one of four diets until sexual maturity (phase 1): a control diet (0.06 μg Hg g-1 dry weight) and three diets contaminated with MeHg at 0.88 (low), 4.11 (medium), and 8.46 μg Hg g-1 dry weight (high). At sexual maturity, male and female fish were paired...

Volatilization and subsequent biodegradation near the water Table make up a coupled natural attenuation pathway that results in significant mass loss of hydrocarbons. Rates of biodegradation and volatilization were documented twice 12 years apart at a crude-oil spill site near Bemidji, Minnesota. Biodegradation rates were determined by calibrating a gas transport model to O2, CO2, and...

Geochemical data were collected to investigate the effects of topography and focused recharge on the transport of agricultural chemicals to groundwater through sandy soils. The research was done at a topographically high (upland) site and a depressional (lowland) site within a corn field. Agricultural chemicals that move readily with water were most directly affected by focused recharge...

Abstract has not been submitted

We developed a satellite transmitter attachment technique for adult Common Loons (Gavia immer) that would help in identifying important migration routes, staging areas, and the location of wintering grounds of birds that breed in the north central United States. During the autumn and winter of 1998, the migration of six adult loons that were radio marked in northern Wisconsin and...

A method using a deuterated surrogate of the avicide 3-chloro-p-toluidine hydrochloride (CPTH) was developed to quantify the CPTH residues in the gastrointestinal (GI) tract and breast muscle tissues in birds collected in CPTH-baited sunflower and rice fields. This method increased the range of a previous surrogate/gas chromatography/mass spectroscopy method from 0−2 to 0−20 μg/g in...

Great Blue Herons (Ardea herodias) and Great Egrets (Casmerodius albus) partitioned feeding habitat based on wetland size at Peltier Lake rookery in east central Minnesota. Great Blue Herons preferred large waterbodies (350 ha), whereas Great Egrets fed most often at small ponds (

We compared the toxicokinetics of methylmercury in captive common loon chicks during two time intervals to assess the impact of feather growth on the kinetics of mercury. We also determined the oral bioavailability of methylmercury during these trials to test for age-related changes. The blood concentration-time curves for individuals dosed during feather development (initiated 35 days...

The results of general circulation model predictions of the effects of climate change from the Canadian Centre for Climate Modeling and Analysis (model CGCM1) and the United Kingdom Meteorological Office's Hadley Centre (model HadCM2) have been used to derive potential impacts on the water resources of the Great Lakes basin. These impacts can influence the levels of the Great Lakes and...

Lake St. Clair is a 430 square mile lake between the state of Michigan and the province of Ontario, which forms part of the international boundary between the United States and Canada in the Great Lakes Basin. Lake St. Clair receives most of its inflow from Lake Huron through St. Clair River, which has an average flow of 182,000 cubic feet per second. The lake discharges to Detroit River...

A new MODFLOW lake package (LAK3) that simulates ground-water/lake interaction was used in simulation of Fish, Mud and Crystal Lakes?three shallow seepage lakes located in northwestern Dane County, Wis. The simulations were done to help determine the cause of increasing lake stages and provide a tool to estimate the effect of pumping water from Fish lake on future lake stages. The ground...

Time series of ground-water head at a mid-marsh site near North Inlet, South Carolina, USA can be classified into five types of forcing signatures based on the dominant water flux governing water-level dynamics during a given time interval. The fluxes that can be recognized are recharge by tides and rain, evapotranspiration (ET), seepage into the near surface soil from below, and seepage...