Publications

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 used by ripar

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. Aluminum (Al

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 weight by day 1

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 in the ti

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 channel catfis

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 banks to agri

During 1993-95, water samples were collected at nine sites on eight streams in the Western Lake Michigan Drainages to attempt to determine pesticide concentrations. The sampling effort was part of the U.S. Geological Survey's National Water- Quality Assessment (NAWQA) Program. Pesticides analyzed for were 58 herbicides and 30 insecticides. Pesticides are used extensively in the study area; applica

Jackson Creek Wetland a 95-acre shallow prairie marsh containing three sediment retention ponds was constructed in 1992 to reduce sediment and nutrient in- flow to eutrophic Delavan Lake. The function of the wetland as a retention system for suspended sediments and nutrients (total and dissolved phosphorus, total ammonia plus organic nitrogen, dissolved ammonia, and nitrite plus nitrate nitrogen)

Park Lake extends to the northeast from the village of Pardeeville in Columbia County (fig. 1). Local residents perceive water-quality problems in the lake that include excessive algae and aquatic plant growth. Algae and plant growth in a lake are controlled, in part, by the availability of phosphorus in the water. However, no measurements of phosphorus enter- ing the lake or of other factors that

Would you like to know streamflow conditions before you go fishing in Wisconsin or in more distant locations? Real-time streamflow data throughout Wisconsin and the United States are available on the Internet from the U.S. Geological Survey. You can see if the stream you are interested in fishing is high due to recent rain or low because of an extended dry spell. Flow conditions at more than 100 s

In 1986, Congress appropriated funds for the U.S. Geological Survey (USGS) to develop the pilot phase of the National Water-Quality Assessment (NAWQA) Program. The long-term goals of this program are to (1) provide a nationally consistent description of current water-quality conditions for a large part of the Nation's water resources; (2) define. long-term trends (or lack of trends) in water quali