Event Title
Three Years Later: Port Susan Bay Estuary Restoration Project
Presentation Abstract
The 2012 Port Susan Bay estuary restoration project in the Stillaguamish River delta was designed to restore 150 acres of once marginal farmland to estuary habitat and tidal influence. The expected impact of the dike setback, however, extends beyond the project footprint to the broader estuary. The return of sediment delivery and freshwater input is expected to help restore marsh habitat in the larger estuary and in particular the northern marsh, which has eroded about 21 meters inland per year since the 1960s. After three years of post-restoration monitoring, unprecedented events have led to unexpected results at the project site and larger estuary. The massive Oso Landslide that occurred in March 2014 along the Stillaguamish River significantly increased sediment delivered to Port Susan Bay during the study period. Record low snow pack and warm weather conditions in 2015 resulted in increased water temperatures and unusually high salinities in the estuary, providing a glimpse of projected climate change conditions. Water temperatures in the Stillaguamish River near the restoration project exceeded thermal barriers to adult salmon migration approximately 20% of the time from May to September 2015. Sediment accretion, favorable for restoring marsh habitat, is occurring in some areas while marsh erosion continues in others. Vegetation recruitment in the restoration project is variable with some areas being colonized by native vegetation and bare areas expanding in others. The bird population in the restoration area shifted from one dominated by passerines and freshwater divers to more dabbling ducks. The collective suite of results from the last three years of monitoring at Port Susan Bay tell an interesting story of an estuary restoration project and potential considerations for future restoration projects.
Session Title
Local Stories and Results
Keywords
Key Words: estuary, restoration, river, delta, monitoring, habitat
Conference Track
Salish Sea Snapshots
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Start Date
2016 12:00 AM
End Date
2016 12:00 AM
Location
2016SSEC
Type of Presentation
Snapshot
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)
Estuarine area conservation--Washington (State)--Port Susan; Restoration ecology--Washington (State)--Port Susan; Ecosystem management--Washington (State)--Port Susan
Geographic Coverage
Salish Sea (B.C. and Wash.); Port Susan (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
Three Years Later: Port Susan Bay Estuary Restoration Project
2016SSEC
The 2012 Port Susan Bay estuary restoration project in the Stillaguamish River delta was designed to restore 150 acres of once marginal farmland to estuary habitat and tidal influence. The expected impact of the dike setback, however, extends beyond the project footprint to the broader estuary. The return of sediment delivery and freshwater input is expected to help restore marsh habitat in the larger estuary and in particular the northern marsh, which has eroded about 21 meters inland per year since the 1960s. After three years of post-restoration monitoring, unprecedented events have led to unexpected results at the project site and larger estuary. The massive Oso Landslide that occurred in March 2014 along the Stillaguamish River significantly increased sediment delivered to Port Susan Bay during the study period. Record low snow pack and warm weather conditions in 2015 resulted in increased water temperatures and unusually high salinities in the estuary, providing a glimpse of projected climate change conditions. Water temperatures in the Stillaguamish River near the restoration project exceeded thermal barriers to adult salmon migration approximately 20% of the time from May to September 2015. Sediment accretion, favorable for restoring marsh habitat, is occurring in some areas while marsh erosion continues in others. Vegetation recruitment in the restoration project is variable with some areas being colonized by native vegetation and bare areas expanding in others. The bird population in the restoration area shifted from one dominated by passerines and freshwater divers to more dabbling ducks. The collective suite of results from the last three years of monitoring at Port Susan Bay tell an interesting story of an estuary restoration project and potential considerations for future restoration projects.
Comments
Key Words:
estuary, restoration, river, delta, monitoring, habitat