Alaska, Montana, Idaho, British Columbia

PhD Research, University of Montana, Influence of Beavers on Pacific Salmon

In the fall of 2013, I completed my PhD in Systems Ecology at the Flathead Lake Biological Station, University of Montana, working with Dr. Jack Stanford. For my dissertation, I studied the influence of beavers (Castor canadensis) on Pacific salmon in a large alluvial floodplain river in western Alaska. Large river floodplains provide critical rearing habitat for juvenile salmon and beavers have the potential to strongly influence the habitat templates of these floodplains by constructing beaver dams. Beavers have the potential to negatively affect salmon production by blocking available habitat. Conversely, beavers may positively impact production by providing larger ponds where fish may grow faster. Understanding how beavers may affect salmon production in important rearing habitats is important because beaver populations have expanded in Alaska, and the reintroduction of beavers where extirpation occurred decades ago is a common management tactic.

My research focused on how habitat modification by beavers influenced a) habitat availability for juvenile salmon, and b) the growth, survival and production of juvenile salmon. Results from my work showed that beavers dramatically altered a large alluvial river floodplain with consequences for rearing juvenile salmon. Using a large-scale observational study of 19 sites on a large alluvial floodplain in a remote portion of western Alaska, we found that beavers modified 87.5% of the off channel habitats, reducing habitat connectivity and adding variability to macroinvertebrates assemblages. Juvenile salmon were able to effectively inhabit and move between early-successional beaver ponds and spring brooks in the parafluvial zone, however almost no salmon were present in abundant late-successional beaver ponds in the orthofluvial zone. These results suggest that beavers have the potential to strongly limit the distribution of juvenile salmon on the floodplain and have been published in Freshwater Biology. To further investigate how beavers influence the growth, survival and production of juvenile salmon I used detailed capture-mark-recapture methods to measure population dynamics in beaver-modified and beaver-free habitats and then estimated how beavers may influence salmon production at the floodplain scale using habitat quantities classified from satellite imagery. Lastly, I used a novel approach, comparing habitat use and juvenile salmon characteristics in two geomorphically similar salmon rivers, one with beavers (Kwethluk River, Alaska) and one without beavers (Kol River, Kamchatka peninsula, Russia) to determine how the presence of beavers may or may not limit habitat connectivity and availability to juvenile salmonids.

Dunce Fire in the Frank Church Wilderness

Dunce Fire in the Frank Church Wilderness

Master's Research, Idaho State University - Effects of Wildfire on Streams

In the spring of 2008, I completed my Masters degree at Idaho State University.  During my time at ISU, I worked in the Stream Ecology Center, under the guidance of Dr. Colden Baxter, and studied the effects of wildfire on aquatic-terrestrial linkages in the Frank Church “River of No Return” Wilderness.  A central objective of this research was to evaluate the potential influences of wildfire on the flux of emerging adult insects from streams to riparian areas, and the consequences for terrestrial predators such as spiders and bats that depend on this prey subsidy.  My work focused on 16 tributaries of Big Creek, which drains into the Middle Fork of the Salmon River.  This study was part of a collaborative effort with the University of Idaho.  We investigated potential influences of wildfire on the flow of energy from aquatic to terrestrial habitats via the emergence of adult insects from streams, and a companion study by the late Dr. Jeff Braatne (riparian ecologist, University of Idaho) and Breanne Jackson (Masters Student, University of Idaho) researched the effects of fire on plant and invertebrate inputs from land to water.  This work within the Frank Church Wilderness was funded by the DeVlieg Foundation and was conducted out of the Taylor Ranch Wilderness Field Station, part of the University of Idaho.  


Photo Credit:  dimnikolov

Salmonid Rivers Observatory Network

Following the completion of my undergraduate degree in Biology from The University of Montana, and completion of two summers of field courses at the Flathead Lake Biological Station, I was a field assistant for the Salmonid Rivers Observatory Network in the Kitlope Heritage Preserve, British Columbia, Canada in the Fall of 2004.  The overall goals of this program include: 1. To quantify biophysical processes producing the Shifting Habitat Mosaic (SHM) and associated biodiversity in the observatory rivers, in context of influences on salmonid population structure and productivity and 2. To devise and promote a new conservation and management protocol for wild salmon rivers that is based on the SHM model.  This project encompasses many study sites along the Pacific Rim, with the Kitlope River added in 2004.  During this 1st field season on the Kitlope I spent two months assisting with surveys of juvenile salmon, collected samples for stable isotope analysis, and helped collect general habitat data with Aaron Hill, masters student of Dr. Jack Stanford.