Olympia Oyster

The Olympia oyster (Ostrea lurida) is one of the only native oyster species on the west coast of the U.S. and Canada. It was once widely distributed from Alaska to Baja California, and covered large expanses of intertidal areas in oyster “beds”.

How Oysters Benefit Nature and People

Olympia oysters were once an important food source for native Californians and an ecologically important habitat for numerous other aquatic organisms. Oysters provide habitat and refuge for other organisms, such as octopus, crabs, and juvenile fishes, who take shelter on the structure oyster beds provide.

Oysters increase both habitat complexity and biodiversity. Here in California, you might notice that the endangered California Least Tern uses oyster shells to line its nest! Oysters are filter feeders, so they improve water clarity and help stabilize mudflats.

California Least Tern

Threats to the Species

Beginning in the 1900s, overharvest of this species, increased coastal development, destruction of wetlands, and increased water pollution led to significant declines of the Olympia oyster. Today, native oysters exist primarily as small remnant populations in bays and estuaries.

However, we have lost an entire native habitat as well as the critical ecological and economic benefits provided by once healthy, fully-functioning components of our estuarine ecosystems.

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Today, over 85% of the world’s oyster reefs have been lost since the 1900′s and are one of the most severely impacted marine habitats on the planet.

Living Shorelines Project

The primary goal of this project is to integrate native Olympia oyster habitat restoration into a larger eelgrass restoration project in Upper Newport Bay in Southern California. This work is designed to address pressing issues related to habitat loss, sea level rise, and increase community awareness about the benefits of protecting marine ecosystems, including:

  • Return of historically present but currently depleted species
  • Enhanced habitat quality and connectivity for fish and wildlife
  • Improved water quality
  • Erosion control
  • Sea level rise adaptation

Restoration of oysters and eelgrass is critical to the health and resiliency of the Newport Bay ecosystem because both species provide many ecosystem services for our coastal wetlands. Oysters increase the abundance of fish and wildlife through their creation of complex habitat and improvement of water quality through filter feeding. Oysters also stabilize sediments and buffer erosion and wave energy, which reduces the impacts of sea level rise.

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Eelgrass meadows provide similar ecosystem services by creating habitat, nursery, and foraging grounds for many invertebrate, fish, and bird species; cycling nutrients; sequestering carbon; stabilizing sediment; and improving water quality.

Simultaneous restoration of the Olympia oyster and eelgrass has never been attempted in southern California, but smaller restoration efforts of both species individually in Newport Bay have been successful.

Coastkeeper has partnered with Dr. Zacherl from CSU Fullerton, Dr. Christine Whitcraft from CSU Long Beach, environmental engineers at Anchor QEA, Inc. as well as students from San Diego State University and the University of Southern California to initiate this innovative and multi-benefit project. Due to the benefits oysters and eelgrass may provide for each other, integrated restoration of the two species is the logical next step to recover greater ecosystem connectivity and function in Newport Bay.

By providing the habitat that native oysters need, we will facilitate the return of this endangered species and the many ecosystem benefits they provide. In addition, by involving the community in the restoration process we will increase community engagement and stewardship in Newport Bay. Lessons learned from our project can also be used to better inform future living shorelines projects.

2017 Oyster Restoration Implementation

Unlike most restoration projects that rely on plastic mesh bags, our oyster restoration used entirely biodegradable materials. This year, 249 students and volunteers hand-sewed more than 500 bags using coconut coir, the fiber found on coconut husks, and filled the bags with 40,000 pounds of Pacific oyster shell to create habitat on which the native Olympia oyster could settle. The project team and over 150 volunteers transported the shell and bags into Upper Newport Bay during the low tide before dawn. Almost 2,000 volunteer hours were spent on the project.

Coastkeeper will use the sites restored with oyster shells as a case study to analyze the potential benefits of restoring eelgrass and oysters simultaneously. As we continue to monitor the area, Coastkeeper anticipates seeing more signs of habitat improvement, including an increase in the population of endangered Olympia oysters and other native species.

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