Measuring restoration progress using river-dependent birds: Lessons from Elwha dam removal
Presentation Abstract
Rivers are among the most important and most impacted entities in the Salish Sea region. Most rivers have altered or missing baselines, resulting from floodplain development, forest clearing, hydropower development, salmon decline, or disruption of Indigenous cultural practices. Though river restoration is being conducted widely, methods for evaluating restoration progress often lack a strong evidentiary basis. Restoration will become more effective and adaptive when decisions are informed by measures connected to restoration goals. Here, we evaluate the potential of river-dependent birds as measures of river restoration associated with dam removal on the Elwha River, WA. Elwha dam removals are the largest and most comprehensively studied in history, providing an ideal system for developing evaluation measures. While extensive results have been reported on geomorphic, vegetative, and fish responses to dam removal, wildlife responses have received less attention. We evaluated the potential of river-dependent birds as measures of Elwha restoration progress by comparing forecasted vs. actual responses of five common species in five river reaches. We developed forecasts based on anticipated changes to riverbird nesting habitats and food sources, using a conceptual ecological model. The five species utilize habitats and food sources spanning a range of conditions that reflect early to late stages in restoration. We determined observed riverbird responses by comparing riverbird field survey data to pre-dam removal baseline data. Survey results were consistent with forecasts for 18 of 25 (72%) species- and reach-specific responses. Strongest concurrence was for species associated with early successional habitats, consistent with the current stage in Elwha restoration. Future riverbird monitoring will provide opportunities to evaluate forecasted responses later in the restoration process. We conclude (1) riverbird monitoring provides informative and efficient measures of restoration progress, (2) restoration evaluation requires pre-restoration baseline data, and (3) comprehensive restoration evaluation should span multiple time scales and trophic levels.
Session Title
Birds
Conference Track
SSE3: The Circle of Life
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-traditionals-120
Start Date
28-4-2022 8:30 AM
End Date
28-4-2022 10:00 AM
Type of Presentation
Oral
Genre/Form
conference proceedings; presentations (communicative events)
Subjects – Topical (LCSH)
Birds--Monitoring--Washington (State)--Elwha River; Wildlife rehabilitation--Washington (State)--Elwha River; Dam retirement--Environmental aspects--Washington (State)--Elwha River; Stream restoration--Washington (State)--Elwha River
Geographic Coverage
Elwha River (Wash.)--Environmental conditions
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Format
application/pdf
Measuring restoration progress using river-dependent birds: Lessons from Elwha dam removal
Rivers are among the most important and most impacted entities in the Salish Sea region. Most rivers have altered or missing baselines, resulting from floodplain development, forest clearing, hydropower development, salmon decline, or disruption of Indigenous cultural practices. Though river restoration is being conducted widely, methods for evaluating restoration progress often lack a strong evidentiary basis. Restoration will become more effective and adaptive when decisions are informed by measures connected to restoration goals. Here, we evaluate the potential of river-dependent birds as measures of river restoration associated with dam removal on the Elwha River, WA. Elwha dam removals are the largest and most comprehensively studied in history, providing an ideal system for developing evaluation measures. While extensive results have been reported on geomorphic, vegetative, and fish responses to dam removal, wildlife responses have received less attention. We evaluated the potential of river-dependent birds as measures of Elwha restoration progress by comparing forecasted vs. actual responses of five common species in five river reaches. We developed forecasts based on anticipated changes to riverbird nesting habitats and food sources, using a conceptual ecological model. The five species utilize habitats and food sources spanning a range of conditions that reflect early to late stages in restoration. We determined observed riverbird responses by comparing riverbird field survey data to pre-dam removal baseline data. Survey results were consistent with forecasts for 18 of 25 (72%) species- and reach-specific responses. Strongest concurrence was for species associated with early successional habitats, consistent with the current stage in Elwha restoration. Future riverbird monitoring will provide opportunities to evaluate forecasted responses later in the restoration process. We conclude (1) riverbird monitoring provides informative and efficient measures of restoration progress, (2) restoration evaluation requires pre-restoration baseline data, and (3) comprehensive restoration evaluation should span multiple time scales and trophic levels.
