As part of a hierarchical approach to classifying watersheds and stream habitats based on geomorphic and geologic criteria, we defined ten classes of fluvial and lacustrine habitats at the scale of valley segments. Valley segments are landscape units which encompass surface waters and the adjacent floodplains and hillslopes with which...
New approaches are needed to quantify and understand spatial patterns of stream fishes and their environment. Concepts in riverine ecology emphasize the importance of thermal zones and gradual longitudinal changes in physical habitat and biota, but little is known about spatial variability within the river continuum. I present a conceptual...
Discrete coldwater patches within warm streams provide potential thermal refuge for coldwater fishes during periods of heat stress. This analysis focused on heterogeneity in stream water temperatures as influenced by local influx of cooler subsurface waters. Using field thermal probes and recording thermistors, we identified and characterized coldwater patches potentially...
Several types of channel morphology measurement parameters used to
characterize fish habitat of small streams are refined, developed and evaluated in terms
of their accuracy, precision, and sensitivity to disturbance. Data for 74 stream reaches
in Oregon and Alaska are used in analysis. Over half the reaches are from a...
To begin to understand freshwater seasonal floodplain fish communities in the context of human alteration of the physical system, species introductions and wetland restoration efforts, I studied fish assemblages in fifteen seasonal floodplain wetlands within four geographic regions (coastal, upper Columbia River estuary, Puget Sound and eastern Oregon/Washington) in the...
Seabirds are an integral component of marine ecosystems, however, because humans typically observe only snapshots of their lives at sea, our understanding of seabird foraging ecology is often limited. A more complete understanding of the ecological roles of seabirds and identification of critical foraging habitats requires the ability to follow...
This thesis focuses on the economic efficiency of alternative habitat, streamfiow, and land use
allocations within a major drainage of the Pacific Northwest. Specifically, productivity of present habitat
and streamfiow conditions is evaluated with respect to anadromous fish species (chinook salmon and
steelhead trout) in the John Day River Basin,...
Bluegill sunfish, Lepomia macrochirus, and cutthroat trout,
Salmo clarki, were exposed to a rapidly declining oxygen tension
for a period of time sufficient to just cause loss of equilibrium in
the fish. During recovery from the stress, measurements of
oxygen uptake, blood lactic acid, blood glucose, liver glycogen,
muscle glycogen,...
Aspects of hydromineral balance in the stenohaline fresh-water
catfish, Ictalurus nebulosus (Le Sueur) were studied at 10° and 20°C.
Temperature did not affect water content significantly. Water content
was 78 ml/100 g body weight, 32% of which is in muscle and 49% in
the skeleton and associated connective tissue. The...
