Publications

High performance liquid chromatography coupled with programmable fluorescence detection was employed for the determination of 15 priority pollutant polycyclic aromatic hydrocarbons (PPPAHs) in water, sediment, and semipermeable membrane devices (SPMDs). Chromatographic separation using this analytical method facilitates selectivity, sensitivity (ppt levels), and can serve as a non-destructive tech

Polyhalogenated hydrocarbons have been implicated in the anomalous sexual differentiation of mammals and reptiles. Here, a temperature-sensitive turtle sex determination assay using the red-eared slider (Trachemys scripta elegans) was used to determine the estrogenic or antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126). Neither TCDD

Organisms are predicted to make trade-offs when foraging and predator avoidance behaviors present conflicting demands. Balancing conflicting demands is important to larval amphibians because adult fitness can be strongly influenced by size at metamorphosis and duration of the larval period. Larvae in temporary ponds must maximize growth within a short time period to achieve metamorphosis before po

Semipermeable membrane devices (SPMDs) were employed to sample sediment pore water in static exposure studies under controlled laboratory conditions using (control pond and formulated) sediments fortified with 15 priority pollutant polycyclic aromatic hydrocarbons (PPPAHs). The sediment fortification level of 750 ng/g was selected on the basis of what might be detected in a sediment sample from a

We developed a system for evaluation of visual function in larval and adult fish. Both optomotor (swimming) and optokinetic (eye movement) responses were monitored and recorded using a system of rotating stripes. The system allowed manipulation of factors such as width of the stripes used, rotation speed of the striped drum, and light illuminance levels within both the scotopic and photopic ranges

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxicity of dioxin and other xenobiotics. In the absence of exogenous ligand, AhR is cytosolic. We investigated how AhR is retained in the cytosol and how dioxin induces AhR to move to the nucleus. Disruption of nuclear export of AhR by the nuclear export inhibitor leptomycin B (LMB) or by mutation of

A toxicity database for ordnance compounds was generated using eight compounds of concern and marine toxicity tests with five species from different phyla. Toxicity tests and endpoints included fertilization success and embryological development with the sea urchin Arbacia punctulata; zoospore germination, germling length, and cell number with the green macroalga Ulva fasciata; survival and reprod

Multiple large floods in 1993-1997 on the Lower Missouri River carved a side-channel chute through the river bottom at Lisbon, Missouri. Although similar in some respects to engineered side-channel chutes designed for habitat rehabilitation projects, the Lisbon Bottom chute has been unique in that it was allowed to evolve for more than four years with minimal stabilization. During the wet years, 1

Understanding the links between land-use changes and physical stream habitat responses is of increasing importance to guide resource management and stream restoration strategies. Transmission of runoff and sediment to streams can involve complex responses of drainage basins, including time lags, thresholds, and cumulative effects. Land-use induced runoff and sediment yield often combine with chann

Workshops in the late 1990's launched the commitment of the U.S. Geological Survey's Biological Resources Division (BRD) to develop and implement decision support systems (DSS) applications. One of the primary goals of this framework document is to provide sufficient background and information for Department of the Interior (DOI) bureau stakeholders and other clients to determine the potential for

The selenium literature has grown substantially in recent years to encompass new information in a variety of areas. Correspondingly, several different approaches to establishing a new water quality criterion for selenium have been proposed since establishment of the national water quality criterion in 1987. Diverging viewpoints and interpretations of the selenium literature have lead to opposing p

The effectiveness of ecological restoration efforts on large developed rivers is often unknown because comprehensive ecological monitoring programs are often absent. Although Eulerian water-quality monitoring programs, such as the National Stream Quality Accounting Network (NASQAN) program, are more common, they are usually not designed for ecological assessment. Therefore, this paper addresses th