Publications

The presence of Mycobacterium avium subsp. paratuberculosis (MAP) in non-ruminant wildlife has raised questions regarding the role of these species in Johne's disease transmission. In this study we tested 472 tissues from 212 animals of six different species of scavenging mammals. All animals were taken from within a 210-square-mile area in Dane and Iowa counties of south central...

We characterized the fish assemblages in second to fifth order streams of the upper Little Sioux River basin in northwest Iowa, USA and compared our results with historical surveys. The fish assemblage consisted of over twenty species, was dominated numerically by creek chub, sand shiner, central stoneroller and other cyprinids, and was dominated in biomass by common carp. Most of the...

The authors determine the composition of a river that is impacted by acid-mine drainage, evaluate dominant physical and geochemical processes controlling the composition, and assess dissolved metal speciation and toxicity using a combination of laboratory, field and modeling studies. Values of pH increase from 3.3 to 7.6 and the sum of dissolved base metal (Cd + Co + Cu + Ni + Pb + Zn)

The gizzard shad (Dorosoma cepedianum) was introduced into 1,955-ha Angostura Reservoir, South Dakota to provide increased prey resources for walleye (Sander vitreus). Linear correlation analysis indicated that following gizzard shad introduction, walleye catch-per-unit-effort and mean length at age have increased over time (r = 0.68 to 0.85, P = 0.02 to 0.001). Walleye stomach contents...

We examined spatial and temporal foraging patterns of Caspian terns and double-crested cormorants nesting in the Columbia River estuary, to potentially identify circumstances where juvenile salmonids listed under the U.S. Endangered Species Act might be more vulnerable to predation by these avian piscivores. Data were collected during the 1998 and 1999 breeding seasons, using point count...

We assessed longitudinal variation in small fish assemblages in the Wind River watershed upstream from Boysen Reservoir, Wyoming and into the reservoir. Twenty-six species were found in the study area, and 12 of the species were believed to have been introduced since settlement by Europeans. Additions and losses of fish species occurred with downstream progression, especially the...

Monitoring natural populations is often a necessary step to establish the conservation status of species and to help improve management decisions. Nevertheless, many monitoring programs do not effectively address primary sources of variability in monitoring data, which ultimately may limit the utility of monitoring in identifying declines and improving management. To illustrate the...

A primary goal of many coastal restoration programs is to increase nekton habitat in terms of both quantity and quality. Using shallow water ponds rehabilitated with a technique called marsh terracing, we examined the quality of nekton habitat created, using and comparing several metrics including nekton density and diversity, functional group composition, and weight-length relationships...

We studied the growth and survival of Spectacled Eider (Somateria fischeri) ducklings to 30 days of age along the lower Kashunuk River on the Yukon-Kuskokwim Delta from 1995 to 2000. We replicated this study at a second site, Kigigak Island, in 1999 and 2000. Age-adjusted estimates of duckling mass and survival at 30 days posthatching were highly variable. Duckling survival was...

This paper examines the seasonal cycling of temperature and salinity in Dexter pit lake in arid northern Nevada, and describes an approach for modeling the physical processes that operate in such systems. The pit lake contains about 596,200 m3 of dilute, near neutral (pHs 6.7–9) water. Profiles of temperature, conductivity, and selected element concentrations were measured almost monthly...

No abstract available.

Because of the importance of Chinook salmon to commercial and subsistence fisheries on the Yukon River, further study of the factors that may affect the success of this species and our ability to manage the fisheries is warranted. Critical to these studies is the determination of the amount of lipids (fat) stored and available to the fish as its primary energy source for migration and...