Publications

A dynamical-systems approach was developed and evaluated for computing ice-affected streamflow. The approach provides for dynamic simulation and parameter estimation of site-specific equations relating ice effects to routinely measured environmental variables. Comparison indicates that results from the dynamical-systems approach ranked higher than results from 11 analytical methods...

Bay Mills Indian Community (BMIC) near Brimley, Mich. (fig. 1), with a population of about 1,000, needs hydrogeologic and ground-water-quality information to help assure a reliable ground-water supply for future economic development. Currently (1995), three wells supply water to a housing development adjacent to Mission Hill, but the remainder of BMIC is dependent on private low-capacity...

Measurements of oxidation-reduction potential (Eh) and concentrations of dissolved hydrogen (H2) were made in a shallow groundwater system contaminated with solvents and jet fuel to delineate the zonation of redox processes. Eh measurements ranged from +69 to -158 mV in a cross section of the contaminated plume and accurately delineated oxic from anoxic groundwater. Plotting measured Eh...

The U.S. Geological Survey studied the relation of land use to nitrate concentrations in the surficial aquifer along the Straight River near Park Rapids in north-central Minnesota (see adjacent map) during 1992 to 1993. Concern about health hazards to humans and livestock from use of ground water contaminated by nitrate prompted the study. Data collected for this study included: (1)...

This study evaluates processes that affect nitrate concentrations in groundwater beneath riparian zones in an agricultural watershed. Nitrate pathways in the upper 2 m of groundwater were investigated beneath wooded and grass-shrub riparian zones next to cultivated fields. Because trees can be important components of the overall nitrate pathway in wooded riparian zones, water sources...

To assess the presence and distribution of a variety of hydro-phobic chemicals in streams in the Red River of the North Basin, bottom sediments were analyzed for trace elements, organochlorines, and polycyclic aromatic hydrocarbons (PAHs). Glaciolacustrine clays and carbonate minerals are common in fine sediments of the region, and can help explain the distribution of many elements...

No abstract available.

Farm-raised 12-month-old female mallards (Anas platyrhynchos) were released at the Winston-Thomas sewage treatment plant, Bloomington, Indiana. Five mallards were sacrificed at the start of the study and at approximately 10-day intervals through day 100. Concentrations of polychlorinated biphenyls (PCBs) in carcasses increased linearly with time of exposure and exceeded 16 μg/g wet...

The disposition of malachite green was determined in channel catfish (Ictalurus punctatus) after intravascular dosing (0.8 mg . Kg-1) or waterborne exposure (0.8 mg . L-1 for 1 h). After intravascular dosing, mean plasma concentrations of the parent compound exhibited a triphasic decline with a terminal elimination half-life of 6.2 h. Malachite green was rapidly absorbed and concentrated...

Carp (Cyprinus carpio) from four sites and channel catfish (Ictalurus punctatus) from one site in the Red River of the North in 1994 were analyzed for total mercury content. In carp, mercury concentrations differed among liver, muscle, and whole bodies (0.11, 0.31, and 0.18 µg/g wet weight, respectively), between large and small size groups, but not location. Mercury distribution in...

Least terns (Sterna antillarum) were studied on the lower Platte River, Nebraska, where this endangered population nests on natural sandbar habitat and on sandpit sites created by gravel dredging adjacent to the river. Theoretically terns should select habitats according to habitat suitability. However, the introduction of sandpits and conversion of tallgrass prairies along the river...

The U.S. Geological Survey (USGS) maps, describes, and seeks to understand Minnesota's mineral, water, and biological resources. The USGS is known for impartial data collection and data interpretation that enable resource planners and others to make informed decisions. Today's issues are more pressing than ever - understanding natural hazards to minimize their effects on life and...