Publications

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...

A recent survey of contaminant information for the Lower Rio Grande Valley (LRGV), Texas, has shown that little is known about contaminants and their impacts on biota of resacas (oxbows) along the US-Mexico border. In 1996, fish were collected from four resacas in the Texas- Tamaulipas border region to assess contaminant loadings and their impacts on fish and birds. Tissue residue...

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)...

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...

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...

Lake Meredith lies on the dry and windswept High Plains of the Texas Panhandle and is a popular recreation area for the region. Oil and gas exploration and extraction have been ongoing at Lake Meredith National Recreation Area since about 1930. More than 250 wells, including those abandoned or relocated, are within the boundaries of the recreation area. Oil and gas wells in the watershed...

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...

Water-resources data for the 2000 water year for Texas are presented in six volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 3 contains records for water discharge at 84 gaging stations; stage only at 9 gaging stations...