Publications

Organochlorine and polycyclic aromatic hydrocarbon compounds are of concern in the Columbia River Basin because of their adverse effects on fish and wildlife. Because these compounds can have important biological consequences at concentrations well below the detection limits associated with conventional water-sampling techniques, we used semipermeable membrane devices (SPMDs) to sample...

No abstract available.

During the last 160 years, land-use changes in the Ozarks have had the potential to cause widespread, low-intensity delivery of excess amounts of gravel-sized sediment to stream channels. Previous studies have indicated that this excess gravel bedload is moving in wave-like forms through Ozarks drainage basins. The longitudinal, areal distribution of gravel bars along 160 km of the...

We created a model to study the process in which nutria (Myocastor coypus) feeding activities lead to erosion and loss of marsh area. This model ties together data on nutria population dynamics and feeding behavior from the literature with data from field studies on the phenology of Scirpus americanus and Spartina patens conducted in the Barataria Basin, Louisiana, USA in 1992. The...

We exposed albino and pigmented medakaOryzias latipes to simulated solar ultraviolet-B (UVB) radiation to determine if albino medaka were less tolerant of UVB radiation than medaka pigmented with melanin. There was no difference in the number of albino and pigmented medaka that died during the exposure period. Spectrophotometric analyses of the outer dorsal skin layers from albino and...

Water resources data for Iowa for the 1998 water year consists of records of stage, discharge, and water quality of streams; stage, and/or contents of lakes and reservoirs; ground water levels and water quality of ground-water wells. This report volume contains discharge records for 32 gaging stations; stage or contents for 2 lakes; water quality for 1 stream-gaging station, and sediment...

This document describes procedures used to collect information, tissues, and fluids for documenting the exposure of fish to environmental contaminants. For the procedures described here, fish are captured (preferably by electrofishing) and held alive until processing (generally

The 2,300-acre Lisbon Bottom Unit, located in central Missouri, became part of the Big Muddy National Fish and Wildlife Refuge (NFWR) after the Great Flood of 1993 devastated the Unit's farmland and network of levees. As a result, interdisciplinary studies were initiated through collaboration among various researches, universities, and State and Federal conservation agencies to...

An analysis of available hydrologic data was conducted to evaluate the effects on groundwater levels in the Missouri River alluvial aquifer caused by changes in Missouri River stage at selected sites in Fremont and Monona Counties in western Iowa. Daily mean ground-water levels and river stage measured during November 1995- September 1996, simulated daily mean river stage for November...

In 1991, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, initiated studies designed to characterize the ground-water quality and hydrogeology in northern Illinois, and southern and eastern Wisconsin (with a focus on the north-central Illinois cities of Belvidere and Rockford, and the Calumet region of northeastern Illinois and northwestern...

The Cambrian-Ordovician aquifer is one of the principal sources of ground water for industry and municipalities in Iowa. The 1998 Iowa Administrative Code Chapter 52.4(3) states that water levels in the Cambrian-Ordovician aquifer are not to decline more than 200 feet from the 1977 baseline. The potentiometric-surface map of the Cambrian-Ordovician aquifer, known locally as the Jordan...

Carbonate rocks of the Silurian-Devonian aquifer are the primary source of water for Cedar Falls, Iowa. A trend of increasing nitrate concentrations has been detected in samples from Cedar Falls water-supply wells 9 and 10, and 1998 nitrate concentrations were close to the U.S. Environmental Protection Agency's Maximum Contaminant Level of 10 milligrams per liter as nitrogen in drinking...