Publications

Fundulus heteroclitus embryos were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during early development using nanoinjection or water bath exposure. TCDD caused developmental abnormalities that included hemorrhaging, loss of vascular integrity, edema, stunted development and death. The LC50 and LD50 of TCDD for Fundulus embryos were ???19.7??9.5 pg TCDD/??l (water bath) and 0.25??0.09 ng

A model is presented to describe the trade-off between food and temperature in bluegills Lepomis macrochirus, where temperature was the primary factor used in determining the patch in which to reside.

This study was conducted in Grand Teton National Park during the summers of 1996 and 1997 to investigate the water quality in two high human use areas: Garnet Canyon and lower Cascade Canyon. To evaluate the water quality in these creeks, fecal coliform, Giardia lamblia, coccidia, and microparticulates were measured in water samples. No evidence of fecal coliform, Giardia lamblia, or coccidia, was

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 videotaped t

Cytochrome P450 1A (CYP1A) induction is a robust marker for exposure to polynuclear aromatic hydrocarbons and planar halogenated aromatic hydrocarbons that are aryl hydrocarbon receptor agonists. We examined CYP1A expression in mesopelagic fishes from the western North Atlantic. Individuals in 22 species were obtained from slope water and the Sargasso Sea in 1977, 1978, and 1993. Aryl hydrocarbon

Currently, conservation efforts are devoted to determining the extent and the causes of the decline of many amphibian species worldwide. Human impacts frequently degrade amphibian habitat and have been implicated in many declines. Because genetic variance is critical in determining the persistence of a species in a changing environment, we examined the amount of genetic variability present in a si

Water and sediment samples were collected from streams in Spearfish Creek, Whitewood Creek, and Bear Butte Creek watersheds in the Black Hills, SD, an area impacted by gold mining operations. Arsenic concentrations that exceeded the U.S. Environmental Protection Agency's Maximum Concentration Limit of 50 μg/L for drinking water were found in water from Annie Creek, a tributary of Spearfish Creek,

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) and great e

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 of Philippi

No abstract available.

The key to successful fish culture is to understand the environmental cues that trigger spawning. In temperate fishes, photoperiod and temperature are important in many species including the family Ictaluridae. The object of this study was to examine whether natural photo-thermal conditions in the laboratory could stimulate the reproductive cycle of Neosho madtoms (Noturus placidus). For three yea

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), aluminum (Al), z