Publications

In 1996 and again in 1999, hatchery personnel noted that some Lake Michigan coho salmon Oncorhynchus kisutch from fall spawning runs on the Platte River weir exhibited abnormal wiggling behavior that was similar to the behavior exhibited by thiamine-deficient Atlantic salmon Salmo salar, from the Baltic Sea. Samples of eggs or gonads, muscle, and liver from salmon and lake trout...

Abstract not supplied at this time

Previous studies have shown that variations in environmental conditions play a major role in explaining variations in plant species richness at community and landscape scales. In this study, we considered the degree to which fine-scale spatial variations in richness could be related to fine-scale variations in abiotic and biotic factors. To examine spatial variation in richness, grids of...

We develop a model that uses repeated observations of a biological community to estimate the number and composition of species in the community. Estimators of community-level attributes are constructed from model-based estimators of occurrence of individual species that incorporate imperfect detection of individuals. Data from the North American Breeding Bird Survey are analyzed to...

No abstract available.

To partially simulate conditions in fish intestinal tracts, we leached six groups of metals-contaminated invertebrates at pH 2 and pH 7, and analyzed the concentrations of four metals (Cd, Cu, Pb, and Zn) and total protein in the leachates. Four of the groups of invertebrates were benthic macroinvertebrates collected from metals-contaminated rivers (the Clark Fork River in Montana and...

Previous studies documented poor productivity of bald eagles (Haliaeetus leucocephalus) in the lower Columbia River (LCR), USA, and elevated p,p???-dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCBs), dioxins, and furans in eagle eggs. From 1994 to 1995, we collected partially incubated eggs at 19 of 43 occupied territories along the LCR and compared productivity and...

We assessed the exposure of fish from the Spring and Neosho Rivers in northeast Oklahoma, USA, to lead, zinc, and cadmium from historical mining in the Tri-States Mining District (TSMD). Fish (n = 74) representing six species were collected in October 2001 from six sites on the Spring and Neosho Rivers influenced to differing degrees by mining. Additional samples were obtained from the...

Nine stream sites in the Blackfoot River, Salt River, and Bear River watersheds in southeast Idaho, USA were sampled in May 2001 for water, surficial sediment, aquatic plants, aquatic invertebrates, and fish. Selenium was measured in these aquatic ecosystem components, and a hazard assessment was performed on the data. Water quality characteristics such as pH, hardness, and specific...

Abalone culture, a developing industry in Baja California, Mexico, would benefit from genetic improvement and controlled breeding. The use of cryopreserved sperm would allow germplasm availability, and this study was designed to develop sperm cryopreservation protocols for red abalone Haliotis rufescens. The acute toxic effects of the cryoprotectants dimethyl sulfoxide (DMSO), propylene...

Adult razorback sucker (Xyrauchen texanus) were exposed to various selenium concentrations in ponds and isolated river channels of the Colorado River near Grand Junction, CO, to determine effects on their growth and residue accumulation over an 11-month period. Adults at Horsethief ponds were fed a commercial diet, whereas fish at Adobe Creek channel and North Pond foraged on natural...

Genetically based phenotypic and ecotypic variation in a dominant plant species can influence ecological functions and patterns of recruitment by other species in plant communities. However, the nature and degree of importance of genotypic differences is poorly understood in most systems.The dominant salt marsh species, Spartina alterniflora, is known to induce facilitative and...