Presentation Abstract

Puget Sound marine shorelines provide Pacific salmon habitat for migration, juvenile rearing, feeding, and refuge. These shorelines are also used as the primary spawning habitat for Pacific sand lance and surf smelt, two forage fish species consumed by many higher level predators including Chinook salmon. Marine nearshore degradation from armoring (bulkheads, sea walls, etc.) and concurrent vegetation loss have detrimental impacts on the survival of salmon. Since the listing of wild Puget Sound Chinook salmon as threatened under the Endangered Species Act in 1999, local efforts have been made in the Puget Sound to improve salmon habitats and recover populations. The 2005 Salmon Habitat Plan adopted by jurisdictions within the Green/Duwamish River and Central Puget Sound Watershed in Western Washington has a primary goal to reduce the amount of shoreline armoring and intertidal fill. To evaluate the progress of the plan’s implementation, we examined two questions: What was the extent of intertidal fill associated with shoreline armoring when the Salmon Habitat Plan was initiated in 2005, and how has the shoreline changed in the ten years since the plan was adopted? Shorelines were mapped using aerial imagery. The extent and area of intertidal fill changes were compared between 2005 and 2015. Results showed a gain of 54,031 ft2 of intertidal habitat since 2005 from restoration efforts. However, there was also a loss of approximately 26,460 ft2 of intertidal habitat. There was no net loss of intertidal habitat with a net gain of 27,571 ft2, representing 51% of the full potential gains that could have been achieved with zero fill. The majority of intertidal area losses were attributed to expansions of existing armored shorelines associated with repairs and rebuilds. This analysis method of quantifying shoreline conditions is a useful tool that provides critical information for tracking and developing adaptive management plans.

Session Title

Habitat Restoration

Keywords

Shoreline armor, Nearshore, King County

Conference Track

SSE1: Habitat Restoration and Protection

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE1-39

Start Date

5-4-2018 10:30 AM

End Date

5-4-2018 10:45 AM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and 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

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Apr 5th, 10:30 AM Apr 5th, 10:45 AM

Marine shoreline armor in King County, 2005-2015

Puget Sound marine shorelines provide Pacific salmon habitat for migration, juvenile rearing, feeding, and refuge. These shorelines are also used as the primary spawning habitat for Pacific sand lance and surf smelt, two forage fish species consumed by many higher level predators including Chinook salmon. Marine nearshore degradation from armoring (bulkheads, sea walls, etc.) and concurrent vegetation loss have detrimental impacts on the survival of salmon. Since the listing of wild Puget Sound Chinook salmon as threatened under the Endangered Species Act in 1999, local efforts have been made in the Puget Sound to improve salmon habitats and recover populations. The 2005 Salmon Habitat Plan adopted by jurisdictions within the Green/Duwamish River and Central Puget Sound Watershed in Western Washington has a primary goal to reduce the amount of shoreline armoring and intertidal fill. To evaluate the progress of the plan’s implementation, we examined two questions: What was the extent of intertidal fill associated with shoreline armoring when the Salmon Habitat Plan was initiated in 2005, and how has the shoreline changed in the ten years since the plan was adopted? Shorelines were mapped using aerial imagery. The extent and area of intertidal fill changes were compared between 2005 and 2015. Results showed a gain of 54,031 ft2 of intertidal habitat since 2005 from restoration efforts. However, there was also a loss of approximately 26,460 ft2 of intertidal habitat. There was no net loss of intertidal habitat with a net gain of 27,571 ft2, representing 51% of the full potential gains that could have been achieved with zero fill. The majority of intertidal area losses were attributed to expansions of existing armored shorelines associated with repairs and rebuilds. This analysis method of quantifying shoreline conditions is a useful tool that provides critical information for tracking and developing adaptive management plans.