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...
Nares Strait is one of three main passages of the Canadian Archipelago that
channels freshwater from the Arctic Ocean to the North Atlantic. There are very few
observations regarding the role of this region on the present day Arctic freshwater budget,
and even less regarding the changes in freshwater fluxes...
Over-winter growth of juvenile salmonids may be linked to ocean survival and thus species persistence. Diet, growth, and prey available to juvenile coho, Oncorhynchus kisutch, were examined from December 2004 to April 2005 in four tributaries of the West Fork Smith River (WFSR), Oregon. Juvenile coho growth rate and condition...
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...
I examined the relative roles of biotic and abiotic factors in structuring redband trout
Oncorhynchus mykiss distributions in the South Fork John Day. I first examined the
relationship between the biological traits of the fish assemblage and riparian-geomorphic features in context of prevailing theories of stream ecology stemming from the...
Freshwater ecosystems in the mid- to
upper-latitudes of the northern hemisphere are particularly
vulnerable to the impact of climate change as
slight changes in air temperature can alter the form,
timing, and magnitude of precipitation and consequent
influence of snowmelt on streamflow dynamics. Here,
we examine the effects of hydro-climate,...
Oncorhynchus mykiss form partially migratory populations with anadromous fish that undergo marine migrations and residents that complete their life cycle in fresh water. Many populations’ anadromous components are threatened or endangered, prompting interest in understanding ecological and evolutionary processes underlying anadromy and residency. In this paper, we synthesize information to...
Surface water and groundwater interactions are a key component in the functioning of stream ecosystems. Exchange of water between the stream and the hyporheic zone creates habitat for aquatic organisms and serves as a control for stream biogeochemical, thermal, and flow processes. This study takes a multi-method field-based approach to...
Large wood (LW) pieces are recognized as an important habitat component for salmon freshwater habitat. As such, they are often used in stream habitat restoration practices despite a lack of knowledge about their impacts on spatial and temporal hydraulic characteristics relevant to fish habitat. In this thesis we present results...
Parasites are ubiquitous members of ecological communities, capable of contributing to the decline of vulnerable populations. Therefore, monitoring parasite level is a critical component for host management. Molecular tools, such as quantitative polymerase chain reaction (qPCR), can be valuable additions to monitoring protocols that assess parasitic disease risk to hosts....