Steelhead and rainbow trout are common names for marine-migratory (anadromous) and freshwater-resident forms of Oncorhynchus mykiss, a partially migratory salmonid fish. Anadromous and resident forms are sympatric and can produce offspring with a life history different from their own (i.e., steelhead parents can produce rainbow trout offspring and vice versa)....
The evolution and maintenance of multiple phenotypes within populations is an interesting evolutionary and ecological question, and is becoming increasingly important for the restoration and conservation of partially migratory species. In particular, why individuals adopt a particular phenotype has been the focus of numerous research efforts. In the partially migratory...
Since the 1964 earthquake and geologic uplift, beavers (Castor canadensis) have expanded their historic range from the inland (outwash plain) Copper River Delta, Alaska to the once tidally influenced areas of the outer area (uplifted marsh). The uplift presents a unique opportunity to observe beaver expansion, habitat selection and influence...
In this study, I examine the influence of habitat gradients created by the 1980 eruption of Mount St. Helens, Washington USA on a recently established Rainbow Trout (Oncorhynchus mykiss) population in the Spirit Lake basin. My goal was to evaluate the responses of fish in seven streams across a volcanic...
The relationship of coastal cutthroat trout (Oncorhynchus clarki clarki) populations in the Muck Creek basin, a 238 km² southern Puget Sound stream basin in western Washington, was examined using starch gel electrophoresis and meristic analysis. Coastal cutthroat trout were collected from six sites throughout the basin including tributaries, portions of...
Relations between the diversity of juvenile anadromous salmonids and pool features
were examined in a managed and a pristine watershed in Oregon during the summer of
1990. There were no differences (p>0.05) in pool depth, velocity or pool wood volumes
between streams. However, the pristine system had twice the number...
Juvenile steelhead are known to associate with shiner groups, though they also compete for food. Steelhead form dominance hierarchies within cohorts and aggressively defend feeding territories against all other fish. This study focused on the differential effect of shiner competition on steelhead of different social standing.
Survival of subordinate juvenile...
Effects of 4-inch (10.16 cm) suction dredge mining on benthic macroinvertebrates in 3rd to 4th order streams were investigated in 1996 by evaluating four mining claim operations in Althouse Creek, Sucker Creek, and Taylor Creek in southwestern Oregon's Rogue River basin. The effects were site-specific. The study showed no significant...
Understanding how populations within a species interact across various geographic and temporal scales is fundamental to developing appropriate conservation strategies. I examined the geographic variation in genetic and meristic characters of coastal cutthroat trout (Oncorhynchus clarki clarki) based on
approximately 1,400 fish sampled from 54 populations spanning their distributional range...