Publications

Permeability/performance reference compounds (PRCs) are analytically noninterfering organic compounds with moderate to high fugacity from semipermeable membrane devices (SPMDs) that are added to the lipid prior to membrane enclosure. Assuming that isotropic exchange kinetics (IEK) apply and that SPMD-water partition coefficients are known, measurement of PRC dissipation rate constants...

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This geographic information system (GIS) data layer shows the generalized lithologic and geochemical, termed lithogeochemical, character of near-surface bedrock in the New England Coastal Basin (NECB) study area of the U.S. Geological Survey's National Water Quality Assessment (NAWQA) Program. The area encompasses 23,000 square miles in western and central Maine, eastern Massachusetts...

The U.S. Geological Survey, in cooperation with the city of Pella, Iowa, conducted a study of the ground-water resources in selected parts of Jasper, Mahaska, and Marion Counties near Pella, Iowa, during 2000–01. The purpose of the study was to describe the ground-water resources in the Pella, Iowa, area. Following a review of available hydrologic and geologic information, the study...

The Water Resources Division of the U.S. Geological Survey, in cooperation with State, county, municipal, and other Federal agencies, obtains a large amount of data pertaining to the water resources of Iowa each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the State. To make...

Mississippi River alluvium in the Muscatine, Iowa, area provides large quantities of good quality ground water for municipal, industrial, and agricultural supplies. Three municipal well fields for the City of Muscatine produce a total of about 27 million gallons per day from the alluvium. A previously published steady-state ground-water flow model was modified, and results from the model...

We conducted a literature review of coypu (Myocastor coypus) introduction and eradication efforts worldwide. The coypu (also called nutria) has been introduced from its origins in South America to every continent except Australia and Antarctica. While perceived in some regions as a valuable resource, in most regions the animals are considered a pest species. Coypus have caused damage to...

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Fundamental issues in the study of predator-prey interactions include addressing how prey coexist with their predators and, moreover, whether predators promote coexistence among competing prey. We conducted a series of laboratory experiments with a freshwater assemblage consisting of two predators that differed in their foraging modes (a crayfish, Procambarus sp., and the western...

Catahoula Lake is the largest natural freshwater lake in Louisiana, covering more than 46 square miles (120 km2) (fig. 1). The lake is a principal stopover and wintering site for hundreds of thousands of migratory waterfowl and shorebirds. Scientists from the USGS National Wetlands Research Center are applying some of the research facility's specialties?wetland plant research, aerial and...

Introduction The Greater Everglades Ecosystem comprises a vast swath of wetlands beginning in central Florida with the headwaters of the Kissimmee River and continuing southward through Lake Okeechobee and then to Florida Bay (Davis 1943). The ecosystem runs some 450 km, north to south, and over 100 km east to west, comprising almost 30,000 km2 of total area. Beginning in the late 19th...