Oysters

What do oysters need to grow in the San Francisco Bay?

The intertidal zone is the area where the land and sea meet, fluctuating between being submerged during high tide and exposed during low tide. This dynamic environment creates distinct zones and specialized organisms that must adapt to both wet and dry conditions, as well as temperature and salinity changes. The Olympia oyster is native to the West Coast of the United States and serves as the target restoration species for Brisbane Shell Beach. Oyster beds are incredibly important for marine ecosystems and coastal communities due to their ability to filter water, provide crucial habitats, and stabilize shorelines. They act as natural water filters by removing pollutants, capturing excess nutrients, and improving water quality. Oyster beds also form reefs that offer shelter and food for a wide variety of fish, shellfish, and other marine life. Additionally, these reefs help protect coastlines from erosion by stabilizing sediments and acting as natural breakwaters. 


What Renew SF Bay aims to accomplish
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RSFB plans to establish sustainable Olympia oyster beds by identifying appropriate areas within OLU28 that provide conducive conditions for sustained growth of native oyster populations and identifying innovative, cost-effective spat capture and growing methods using adaptive nature-based solutions such as substrate constructs utilizing logs and sanitized shells in compostable bags.

Eelgrass

The subtidal zone is a coastal region that is consistently submerged under water, encompassing nearshore and offshore regions. It's a more stable environment than the intertidal zone, offering less exposure to air, drastic temperature fluctuations, and sunlight variations. Subtidal communities are diverse, including kelp forests, seagrass beds, and coral reefs found in shallower areas, while deeper regions are dominated by phytoplankton. 
RSFB is proposing the establishment of sustainable Zostera marina eelgrass meadows by identifying appropriate areas within OLU28 that provide the ideal conditions for sustained growth. 

​Eelgrass beds are crucial for marine ecosystems and coastal protection. They provide essential habitat, shelter, and nursery grounds for a wide variety of fish, invertebrates, and birds. Eelgrass also helps stabilize sediments, reducing erosion and improving water quality.  The goal is to identify innovative and cost-effective seeding methods such as the use of naturalized manila clams with native eelgrass seeds glued onto their shells and disbursed within the desired growth areas.

Image Source: San Francisco Bay Subtidal Habitat Goals Report. 2010

Spotlight

The Brisbane Marina Gardens project is a wetland restoration surrounding the harbor master’s office. The goal of the project is to remove invasive iceplant and reintroduce native salt grass and its companion plants like pickleweed, alkali health, fleshy jaumea and marsh gumplant. 

The project is expected to take place during the Spring of 2026 pending approval by the City of Brisbane. Volunteers will take part in every stage of the project: invasive species removal, soil remediation, planting and regular upkeep. The garden is expected to be self-sustaining following establishment.

Native Plants

​Plants in the Upland Zone

Native plants are vital to restoration across every tide zone—subtidal, intertidal, and upland—because they support healthy, resilient coastal ecosystems.  Across all zones, these plants enhance biodiversity, increase ecosystem stability, and play a key role in adapting to sea-level rise and climate change.

Sierra Point is a landfill, susceptible to salt water intrusion. Multiple lombardy poplars have died and future plantings must take sea-level rise into consideration. The soil also contains toxic levels of heavy metals and is highly sodic, unsupportive of many native plants without considerable soil work. 

The upland zone is at the edge of the shoreline above tidal action, characterized by a reduced risk of flooding, absence of anaerobic conditions and lower saline soil conditions. Native plants are crucial for healthy shoreline ecosystems as they stabilize shorelines, improve water quality, support biodiversity, and provide habitat for wildlife.  Their deep root system prevents erosion, and they filter pollutants from runoff, preventing them from entering the water.

Native plants also offer food and shelter for various species, contributing to a balanced and resilient ecosystem.  Removing invasive plants and maintaining the upland zone is key to the restoration process. RSFB plans to incorporate the use of proper site planning; assessment, preparation, planting and maintenance. These methods are needed to identify and remove invasive species to allow the native plants to stabilize the shoreline areas.

Toyon, commonly known as Christmas Berry is a native stalwart. (Heteromeles arbutifolia)

Plants in the intertidal zone

The intertidal zone includes a group of plants that make up tidal salt marshes, which are adapted to withstand high physiological stress from heat, intermittent waterlogging, and high salinity. During acrid summers in San Francisco, salt marsh plants endure high saline environments followed by wet winters inundated by fresh water. While salt marshes in San Francisco Bay historically served as hotspots of plant and animal diversity, providing habitat for invertebrates that migratory birds fed on, the majority of tidal salt marshes in San Francisco Bay were lost during the 19th and 20th centuries due to reclamation. Today, there is a significant push to recover salt marshes for carbon capture, biodiversity, resting grounds for migratory birds, and their promise as horizontal levees. 
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Renew SF Bay is committed to enhancing the shoreline with native plant species and mitigating the growth of invasive species. Pacific Cordgrass is an important colonizer of salt marshes, providing habitat and protection for wildlife. There is ongoing effort to remove the invasive, hybridized cord grass in San Francisco Bay. Other important species of native marsh plants include pickleweed, California sea lavender, marsh gumweed, and alkali heath. 
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Pickleweed (Salicornia virginica) growing with saltgrass (Distichlis spicata)
​along the shoreline in San Francisco Bay.