Presentation Abstract
The ongoing removal of two hydroelectric dams from the Elwha River on Washington’s Olympic Peninsula provides an unprecedented opportunity to study the effects of dam removal and subsequent salmon restoration on river-dependent wildlife species. Salmon are widely known to distribute marine nutrients into freshwater systems, providing benefits to both riverine and upland wildlife communities through improved nutrient availability. We examined two species of river-dependent wildlife (river otter Lontra canadensis, and American dipper Cinclus mexicanus) to gather data on home range and seasonal movement patterns, body condition, and dietary contributions from marine-derived nutrients prior to and during dam removal. We radio-tracked ten river otters in the Elwha River and adjacent Salish Sea, and collected biological samples from all otters captured in the Elwha River as well as 246 dippers captured across four watersheds with varying qualities of salmon runs. We are using stable isotopes (C, N) to track marine derived nutrient contributions to the diets of otters and dippers, species that are both sensitive indicators of aquatic food web quality. In both species, stable-isotope ratios were more enriched in tissues from areas with intact salmon migrations, indicating greater consumption of salmon tissues and potential enrichment of invertebrate prey. In dippers, females breeding in areas with salmon migrations were in better condition and both sexes were more likely to occupy territories in fall. Adult condition patterns were more pronounced behind anthropogenic, compared to natural, obstructions. These patterns indicate that dams have sizeable individual level impacts on aquatic consumers and provide a valuable baseline to track the recovery of this watershed following completion of dam removal.
Session Title
Session S-06F: Elwah River Restoration: Evolution of Habitats and Ecosystems During a Dam Removal Project
Conference Track
Restoration
Conference Name
Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)
Document Type
Event
Start Date
1-5-2014 1:30 PM
End Date
1-5-2014 3:00 PM
Location
Room 602-603
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Dam retirement--Environmental aspects--Washington (State)--Elwha Dam; Estuarine restoration--Washington (State)--Elwha River Watershed; Predation (Biology)--Washington (State)--Elwha River Watershed; North American river otter--Food--Washington (State)--Elwha River Watershed; American dipper--Food--Washington (State)--Elwha River Watershed
Geographic Coverage
Salish Sea (B.C. and Wash.); Elwha River Watershed (Wash.); Elwha Dam (Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Included in
Responses of river-dependent wildlife to dam removal, salmon restoration, and nutrient subsidies in the Elwha River Watershed, Olympic Peninsula, Washington
Room 602-603
The ongoing removal of two hydroelectric dams from the Elwha River on Washington’s Olympic Peninsula provides an unprecedented opportunity to study the effects of dam removal and subsequent salmon restoration on river-dependent wildlife species. Salmon are widely known to distribute marine nutrients into freshwater systems, providing benefits to both riverine and upland wildlife communities through improved nutrient availability. We examined two species of river-dependent wildlife (river otter Lontra canadensis, and American dipper Cinclus mexicanus) to gather data on home range and seasonal movement patterns, body condition, and dietary contributions from marine-derived nutrients prior to and during dam removal. We radio-tracked ten river otters in the Elwha River and adjacent Salish Sea, and collected biological samples from all otters captured in the Elwha River as well as 246 dippers captured across four watersheds with varying qualities of salmon runs. We are using stable isotopes (C, N) to track marine derived nutrient contributions to the diets of otters and dippers, species that are both sensitive indicators of aquatic food web quality. In both species, stable-isotope ratios were more enriched in tissues from areas with intact salmon migrations, indicating greater consumption of salmon tissues and potential enrichment of invertebrate prey. In dippers, females breeding in areas with salmon migrations were in better condition and both sexes were more likely to occupy territories in fall. Adult condition patterns were more pronounced behind anthropogenic, compared to natural, obstructions. These patterns indicate that dams have sizeable individual level impacts on aquatic consumers and provide a valuable baseline to track the recovery of this watershed following completion of dam removal.
