Publications

The use of lipid-containing semipermeable membrane devices (SPMDs) is becoming commonplace, but very little sampling rate data are available for the estimation of ambient contaminant concentrations from analyte levels in exposed SPMDs. We determined the aqueous sampling rates (R(s)s; expressed as effective volumes of water extracted daily) of the standard (commercially available design)...

A comprehensive set of soil characteristics were examined to determine the effect of soil on the transport of agrichemicals to ground water. This paper examines the relation of local soil characteristics to concentrations and occurrence of nitrate, atrazine (2-chloro-4 ethylamino-6-isopropylamino-s-trazine), and atrazine residue [atrazine + deethylatrazine (2-amino-4-chloro-6...

Ideally, general ecological relationships may be used to predict responses of natural communities to environmental change, but few attempts have been made to determine the reliability of predictions based on descriptive data. Using a previously published structural equation model (SEM) of descriptive data from a coastal marsh landscape, we compared these predictions against observed...

In PLHC-1 hepatoma cells, benzo[a]pyrene (B[a]P) caused a maximum induction of cytochrome P4501A (CYP1A) activity, measured as ethoxyresorufin O-deethylation (EROD), after 4 to 8 h of exposure, depending on the B[a]P concentration. The decline of EROD activity at longer exposure times was probably caused by the rapid metabolism of B[a]P in this system (57% metabolism within 4 h...

Fingerling channel catfish Ictalurus punctatus exposed to simulated ultraviolet-B radiation at an average daily dose of 2.9 J/cm2 were quite sensitive to the radiation. After a 24-h exposure, thinning of the most dorsal epidermis frequently was accompanied by edema. Compared with epidermis of unexposed fish, mucous cells in exposed fish were less superficial and club cells were less...

We describe the development, structure, and corroboration process of a simulation model of animal behavior (MOAB). MOAB can create spatially explicit, individual-based animal foraging models. Users can create or replicate heterogeneous landscape patterns, and place resources and individual animals of a goven species on that landscape to simultaneously simulate the foraging behavior of...

Work was performed to determine the feasibility of selectively detoxifying organic contaminants in sediments. The results of this research will be used to aid in the development of a scheme for whole-sediment toxicity identification evaluations (TIEs). The context in which the method will be used inherently restricts the treatments to which the sediments can be subjected: Sediments...

No abstract available.

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...

Previous research on the distribution of Neosho madtoms, which are Federally-listed as threatened, indicated a positive relationship between density of Neosho madtoms and cumulative density of other riffle-dwelling benthic fishes. This suggested that interspecific competition was not limiting Neosho madtom populations. We provide further evidence that interspecific competition is not...

A method is described for preparing formulated sediments for use intoxicity testing. Ingredients used to prepare formulated sediments included commercially available silt, clay, sand, humic acid, dolomite, and α-cellulose (as a source of organic carbon). α-Cellulose was selected as the source of organic carbon because it is commercially available, consistent from batch to batch, and low...

Anthropogenic selenium contamination of aquatic ecosystems was first associated with cooling reservoirs of coal-fired power plants in the late 1970s, and later with drainage water from agricultural irrigation activities in the 1980s. In the 1990s, selenium contamination has been raised as a concern in the recovery of currently endangered fish in the Colorado River system. Widespread...