Publications

Food habits of Redheads (Aythya americana) investigated at the Horicon National Wildlife Refuge, Wisconsin, during 1983-1985. Prelaying females consumed plant material almost exclusively, primarily seeds of moist-soil plant species. The diet of laying and incubating females was dominated by seeds but also contained 16-17% animal matter. Consumption of animal matter during egg production...

We evaluated the potential loss of target benthic macroinvertebrates from coarse-mesh field wash down of samples through a 1.18-mm mesh sieve nested on a 0.60-mm mesh sieve. Visible target organisms (midges, mayflies, and fingernail clams) in the 1.18-mm mesh sieve were removed from the sample and enumerated in the field. The entire contents of both sieves were preserved for subsequent...

We compared four different methods for estimating predation rates by North Sea cod (Gadus morhua). Three estimates, based on gastric evacuation rates, came from an ICES multispecies working group and the fourth from a bioenergetics model. The bioenergetics model was developed from a review of literature on cod physiology. The three gastric evacuation rate models produced very different...

Lesser scaup (Aythya affinis) winter in the Grand Calumet River—Indiana Harbor Canal (GCR-IHC) drainage into southern Lake Michigan, a polluted oasis in the highly urban and industrial corridor of northern Illinois and Indiana. The GCR-IHC is an important wintering area for lesser scaup in northwestern Indiana, especially after Lake Michigan freezes, because of the lack of other wildlife...

Chemistry and stable-isotope data for water from wells completed in the Marshall aquifer within the Michigan Basin were used to prepare maps that show area! variations of δ18O; distribution of dissolved solids, dissolved chloride, dissolved iron, and dissolved sulfate; and distribution of hydrochemical facies. Delta oxygen-18 values indicate the presence of modern meteoric water (δ18O

Unconsolidated glacial sand and gravel deposits provide virtually all water used by residents of the Lac du Flambeau Indian Reservation. Well yields of 10 to 20 gallons per minutecan be obtained from these deposits throughoutthe reservation. Yields of 1,200 gallons perminute are obtained from wells for a fish-rearingfacility near the village of Lac du Flambeau. Thesaturated thickness of...

During the past 20 years, aquaculture has grown both as a vital tool for fisheries management and as a viable industry. But now a crisis has arisen from the Food and Drug Administration's (FDA) increased regulation of drug use in aquaculture in response to public concerns about human food safety, human health, and environmental effects. Lack of approved drugs and chemicals has...

Monroe County relies heavily on its aquifers and streams for drinking water, irrigation, and other ~ses; however, increased water use, high concentrations of certain constituents in ground water, and droughts may limit the availability of water resources. Although the most densely populated parts of the county use water from the Great Lakes, large amounts of ground water are withdrawn...

In most rivers, transport of various constituents occurs largely during short-term, high-intensity events. A method is described to make regionalized estimates of the long-term average loads of selected streamwater constituents, as well as loads occurring during high-flow events with specified recurrence intervals. This method is used to estimate the load of suspended sediment, total...

No abstract available.

Duckling survival, an important factor affecting annual recruitment, has not been determined adequately for canvasbacks (Aythya valisineria). We investigated the magnitude, timing, and causes of mortality of canvasback ducklings from hatch to fledging at the Agassiz National Wildlife Refuge (NWR) in northwestern Minnesota during 1987-90. During the 4 years, 217 day-old ducklings were...

Sediment traps are being used in some pollution monitoring programs in the USA to sample suspended solids for contaminant analyses. This monitoring approach assumes that the characteristics of solids obtained in sediment traps are the same as those collected in whole-water sampling devices. We tested this assumption in the upper Mississippi River, based on the inorganic particle-size...