Progress over the past 30 years has revealed many strengths of the rainbow trout as an alternative model for environmental carcinogenesis research. These include low rearing costs, an early life-stage ultrasensitive bioassay, sensitivity to many classes of carcinogen, a well-described tumor pathology, responsiveness to tumor promoters and inhibitors, and a mechanistically informative nonmammali...

Wine-Spring Creek basin, in the mountains of North Carolina’s Nantahala National Forest, is an ecosystem management demonstration site, iu which ecological concepts for management and restoration are tested. Large woody debris (LWD) is an important link between streams and the adjacent riparian forest, but evidence for the connection between LWD and trout in southern Appalachian streams is limi...

The course of a VHS (viral haemorrhagic septicaemia) infection in brown trout Salmo trutta fario L. in a stream was followed for 4 yr using anti-VHS virus antibodies a s the indication of infection. Trout were caught by electrofishing and the presence of anti-VHS virus antibody in the serum was determined by counter-current immunoelectrophoresis. There were fluctuations in the prevalence of ant...

The North American beaver (Castor canadensis) is a managed species in the United States. In northern Wisconsin, as part of the state-wide beaver management program, the Chequamegon-Nicolet National Forest removes beavers from targeted trout streams on U.S. Forest Service lands. However, the success of this management program has not been evaluated. Targeted removals comprise only 3% of the annu...

For species with declining populations, captive rearing with subsequent release into natural habitats ("head-starting") is often used as part of a conservation strategy. One challenge to head-starting programs is that head-started individuals can suffer high rates of postrelease predation. Head-starting programs are currently being established for hellbenders (Cryptobrancus alleganeinsis), larg...

—Introduction of lake trout Salvelinus namaycush into a system can add a trophic level, potentially affecting organisms at lower trophic levels. Similar to many lakes and reservoirs in the western United States, lake trout were introduced into Yellowstone Lake, Wyoming. Previous studies showed that lake trout reduced the population and altered the size structure of native Yellowstone cutthroat ...

When nonnative species become established within new communities, competition may play a role in determining the persistence of ecologically similar native species. In western North America, many native cutthroat trout (Oncorhynchus clarkii) populations have been replaced by nonnative rainbow trout (Oncorhynchus mykiss). Superior competitive ability of rainbow trout and cutthroat–rainbow trout ...

Whirling disease has spread rapidly throughout the United States the past 20 years, but predicting its impacts to trout populations has been problematic. Using a database that contained mark-recapture information for 384,938 trout during the years 1980-2007, a before-after control-impact study design was used to analyze data from infected river sections and non-infected reference sections on si...

A Streptococcus species biochemically and serologically identical to the rainbow trout pathogenic Streptococcus species was isolated from the internal organs of the fish specific leech, Batracobdelloides tricarinata. These leeches were obtained from Roodeplaat Dam, near Pretoria, in which rainbow trout do not occur. This is the first isolation of this bacterium from an environmental source not ...

Effective conservation of Cutthroat Trout Oncorhynchus clarkii lineages native to the Rocky Mountains will require estimating effects of multiple stressors and directing management toward the most important ones. Recent analyses have focused on the direct and indirect effects of a changing climate on contemporary ranges, which are much reduced from historic ranges owing to past habitat loss and...