Publications

Pesticides and heavy metals are common environmental contaminants that can cause neurotoxicity to aquatic organisms, impairing reproduction and survival. Neurotoxic effects of cadmium and carbaryl exposures were estimated in larval rainbow trout (RBT; Oncorhynchus mykiss) using changes in physiological endpoints and correlations with behavioral responses. Following exposures, RBT were...

The objectives of this study were to compare approaches for evaluating the combined effects of chemical mixtures on the toxicity in field-collected sediments and to evaluate the ability of consensus-based probable effect concentrations (PECs) to predict toxicity in a freshwater database on both a national and regional geographic basis. A database was developed from 92 published reports...

During 1997 we evaluated reproductive success in colonial water birds nesting in the Lower Rio Grande Valley (LRGV), Texas, and correlated success with concentrations of contaminants in eggs. We also measured steroid hormones and gonadosomatic index (GSI) as biomarkers of endocrine effects in common carp (Cyprinus carpio). Nest and fledging success of green herons (Butorides virescens)...

Landsat Thematic Mapper images from 1990 to 1996 and collateral data sources were used to classify the land cover of the Mermentau River Basin (MRB) within the Chenier Plain of coastal Louisiana. Landcover classes followed the definition of the National Oceanic and Atmospheric Administration's Coastal Change Analysis Program; however, classification methods had to be developed as part of...

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...

This study is an evaluation of the potential environmental impacts of contaminated groundwater from the ASARCO metals refining facility adjacent to the Missouri River in Omaha, Nebraska. Surface waters, sediments, and sediment pore waters were collected from the Burt-Izard drain, which transects the facility, and from the Missouri River adjacent to the facility. Groundwater was also...

As a follow-up of an initial overview of environmental problems caused by mining activities on Marinduque Island, Philippines, USGS and TAMU-CC scientists went to Marinduque in October 2000 to do a preliminary assessment of potential impacts of mining-related activities on the marine environment. Like the previous visit in May 2000, the marine assessment was conducted at the invitation...

The aquatic fate of the triethylamine salt formulation of triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) was determined in whole-pond applications in closed (no water exchange) systems in California, Missouri and Texas in two studies conducted in 1995 and 1996. These studies determined dissipation rates of triclopyr and its principal metabolites, 3,5,6-trichloropyridinol (tcp) and...

Acid drainage from abandoned mines and from naturally-acidic rocks and soil in the upper Animas River watershed of Colorado generates elevated concentrations of acidity and dissolved metals in stream waters and deposition of metal-contaminated particulates in streambed sediments, resulting in both toxicity and habitat degradation for stream biota. High concentrations of iron (Fe)...

Eggs of neotropic cormorants (Phalacrocorax brasilianus), black-crowned night herons (Nycticorax nycticorax), and great egrets (Ardea alba) nesting on several locations in Galveston Bay (TX, USA) and at two control sites outside the bay were collected during April–May 1996 and analyzed for chlorinated pesticides, PCBs, polychlorinated dibenzo-p-dioxins, and polychlor-inated dibenzofurans

Marbled teal (Marmaronetta angustirostris) and white‐headed duck (Oxyura leucocephala) are the two European ducks threatened with global extinction. We investigated lead (Pb) poisoning in stifftails (Oxyura spp., n = 83) and marbled teal (n = 80) shot or found dead or moribund in Spanish wetlands via gizzard examination and liver, bone, and blood Pb analysis. Ingested Pb shot was present...

This report presents the results of a study conducted by the U.S. Geological Survey in cooperation with the Missouri Department of Conservation to describe the hydrology, sediment transport, and sediment deposition along a selected reach of Long Branch Creek in Macon County, Missouri. The study was designed to investigate spatial and temporal characteristics of sediment deposition in a...