Spring chinook salmon, Oncorhynchus tshawytscha, in the Snake River Basin are listed as endangered under the Endangered Species Act. The typical life history of spring chinook salmon is semelparous. An experiment was performed to see if mature male spring chinook salmon parr could be reconditioned after hand-spawning and spawned in...
Both development and post-structuralist anthropologists have
critiqued development. Development anthropologists are concerned
that development does not take adequate account of the social and
cultural factors of developing nations, while post structuralists question
the ontology of development and assert that domination over
developing nations is inherent in the concept of development....
Invasion by nonnative brook trout (Salvelinus fontinalis) often results in replacement of bull trout (Salvelinus confluentus) in western North America, but the causal mechanisms are not well understood. Removal of brook trout from 1992 to 2000 from Sun Creek in southern Oregon, provided an opportunity to investigate the changes in...
The growth, size and age composition, mortality and reproduction of darkblotched rockfish (Sebastes crameri) were examined using fishery data and analysis of fish
characteristics for samples collected of f the Oregon coast. A total of 1060 fish, caught by commercial groundfish and shrimp trawlers operating out of Newport, Coos Bay...
Rockfish of the genus Sebastes are important components of Oregon reef communities. I examined patterns of age and growth in young-of-year rockfish across two nested spatial scales – local and regional – along the Oregon coast. Using otolith microstructural examination, I examined the relative importance of local versus regional factors...
Seagrass ecosystems are considered some of the most productive coastal habitats in the world. One such seagrass within estuaries of the Pacific Northwest, Zostera marina (eelgrass), is recognized to be an ecosystem engineering species that provides many important ecosystem functions and services. In 2010, construction of the National Oceanic and...
The term "interaction" in evolutionary biology and ecology
describes the relationships among variables in two classes of causal
models. In the first, "interaction" refers to the influence of a
single putatively causal variable on a variable of interest. In the
second class of models, the term applies when a third...
Considerable controversy exists about how fish assemblages are
organized. I explicitly took fish movement into account while I
studied the effects of disturbance, habitat complexity, and predation
at different times of the summer to understand the major factors
influencing assemblage structure in a high desert Oregon stream. The
effects of...
Nest sites of reticulate sculpin (Cottus perplexus) were located in two stream reaches, one from a basalt basin and one from a sandstone basin. Stream reaches were similar in gradient, basin area, elevation, climate, and riparian vegetation but differed in biologic community structure and substrate characteristics. An electivity index was...
Predator-prey interactions have historically been studied to explain patterns of organization observed in populations and communities. They have also been important in understanding the evolution of antipredator responses in prey and counterstrategies in predators. Despite the breadth of knowledge that exists for heterospecific interactions, relatively few studies have investigated the...