Publications

Pretty Lake is a 64 acre, sandy-bottomed groundwater flow-through lake that has a history of hydrologic disturbance. Residents and regulators require a better understanding of lake-groundwater interaction to develop measures to protect the lake's hydrologic system and water quality. A groundwater flow model was constructed as a tool to synthesize field data collected at the site...

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...

Polychlorinated Biphenyls (PCBs) in the Great Lakes Despite being banned since the 1970's, polychlorinated biphenyls (PCBs) continue to pose a threat to the environment because of their persistence and toxicity to organisms ranging from minute algae to fish, waterfowl, and human beings. PCBs, a set of 209 related chlorinated organic compounds, had various industrial uses such as in...

Electrical-resistivity logs and water-quality data were used to delineate the fresh water/saline-water interface in a 22,000-square-mile area of the central Michigan Basin, where Mississippian and younger geologic units form a regional system of aquifers and confining units. Pleistocene glacial deposits in the central Lower Peninsula of Michigan contain freshwater, except in a 1,600...

Chemical and stable-isotope data of water from wells completed in the Saginaw aquifer in the central Lower Peninsula of Michigan were used to prepare maps that show areal variation of δ18O; distribution of dissolved solids, dissolved chloride, dissolved iron, dissolved sulfate; and distribution of hydrochemical facies. Delta oxygen-18 values indicate the presence of modern meteoric water...

No abstract available.

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...

I used replicated 37.8 1 aquaria in a factorial design (four densities of zebra mussel, Dreissena polymorpha; two hydrologic regimes) to determine if the survival or growth of juvenile fathead minnows (Pimephales promelas) was affected by the density of zebra mussel or by the retention time of the test system. None of the fathead minnows died during the 30-d experiment. However, growth...

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...