San Francisco Bay Living Shorelines Project
Coastal Conservancy & 17 regional partners
At two locations, the San Francisco Bay Living Shorelines Project is demonstrating the potential of establishing native eelgrass and oyster beds to protect the San Francisco Bay shoreline while creating biologically rich and diverse habitat that is resilient to changing environmental conditions.
Habitats created through the project were quickly shown to benefit a wide variety of wildlife while decreasing energy from wave action. The decreased wave energy reduces flooding and erosion of the shoreline and allows sediments to accrete, enabling the shoreline to rise along with sea levels.
Findings from this project are being used to design future projects and develop best practices for managing living shorelines and submerged habitats.
- Oyster shell-bag mounds and eelgrass beds were planted 150-250 meters offshore and are being monitored to observe their biological and physical effects and impacts as living shorelines.
Monitored: Wave attenuation, sediment accretion, bird and fish utilization, and water quality
Four alternatives to oyster shell-bag mounds were tested as structures for oyster settlement (due to scarcity of shells for shell-bag mounds).
- Monitored: Oyster recruitment and growth
- Sites were chosen 150-250m offshore, dependent on slope, to achieve eelgrass’s preferred depth; oysters can tolerate higher tidal elevations.
- Site access had to be carefully planned in order to access shallow subtidal environments.
- More than half a million clean oyster half shells (six semi-truck loads) were used to build reefs.
- Eelgrass was transplanted from different sites to test which donors performed best.
Oyster Settlement Results
- Reefs reduced 30-50% of wave energy.
- Sediment accumulated 15 cm around oyster shell bags and 24 cm inside.
- Many rare and valuable species such as black oystercatchers, dungeness crabs, and steelhead were quickly attracted to the site.
Eelgrass Restoration Results
- Eelgrass transplanted from Point Molate was more successful than donors from Point San Pablo due to similar muddy conditions.
- The ephemeral nature of beds in San Francisco Bay may require ongoing restoration maintenance.
Combination of Oyster and Eelgrass Beds
- Combining oyster and eelgrass beds in one project site increases the diversity of fish and invertebrates using the site, but oyster beds should be spaced apart because of a trending negative impact on eelgrass (likely due to competition for space).
Each location is unique, and site-specific characterizations should be considered in the shoreline design.
Future Research: Test more locations and designs and test the reduction of wave energy at other locations with different slopes, fetch, and sediment types. Look for other sources for shells for shell bags (e.g., develop a shell recycling program).
Costs: $2.1 million ($400k for design and permitting, $450k for construction, $1.25M for monitoring)
Timeline: Design & Pre-project monitoring, 2011-12; Permitting, 2012; Construction, summer 2012; Monitoring, 2012-present
Partners: US EPA, NOAA, USGS, Coastal Conservancy, CA Dept. of Fish and Wildlife, Wildlife Conservation Board, UC Davis, SF State University Romberg Tiburon Center, San Francisco Estuary Partnership, The Nature Conservancy, CA Wildlife Foundation, ESA/PWA, Dixon Marine Services, Drakes Bay Oyster Company (shells)
Photo credits: Marilyn Latta, Stephanie Kiriakolopolos, Susan de la Cruz
- Job Posting: Bay Area Deputy Program Manager“Love San Francisco Bay, the environment, and managing people? This might be the job for you!” The position is located in Oakland, CA. Applications received without ALL the required items (state application std. 678, copy of diploma and/or transcripts, cover letter and SOQ), will NOT receive further consideration for this position. This advertisement will be used for […] (Read more on Job Posting: Bay...)
- Job Posting: Project Development Analyst (Limited Term/Full Time)“Love the California coast and the environment? This might be the job for you!” The position headquarters is located in Oakland, CA. Applications received without ALL the required items (state application std. 678, copy of diploma and/or transcripts, and cover letter), will NOT receive further consideration for this position. This position is advertised as limited-term/full-time but may become permanent/full-time. […] (Read more on Job Posting: Project...)
- Job Posting: Executive OfficerExecutive Officer/California Coastal Conservancy The State Coastal Conservancy is seeking a new Executive Officer. This is an exciting and rare opportunity for an experienced professional to lead an organization’s efforts to protect, restore, protect and improve natural lands and waterways and increase access to the coast for families and individuals in California. Mission Statement […] (Read more on Job Posting: Executive...)