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Eelgrass Restoration

Restoring Eelgrass is Vital to Our Marine Ecosystem


Eelgrass meadows in the San Juan Islands are facing various threats from human activities like boating, nutrient runoff, and climate change. Our restoration project is dedicated to revitalizing essential eelgrass habitats, shown to be in decline at several sites in the San Juans Islands based on monitoring conducted by the Washington State Department of Natural Resources. 

Eelgrass provides essential habitat for species like salmon, herring, and Dungeness crab, which in turn support the entire marine food chain. It also plays a key role in stabilizing shorelines, mitigating coastal erosion and significantly enhancing local water quality by serving as a nutrient sink. Through these ecosystem services, eelgrass protects community properties and is invaluable in maintaining the overall health of the marine environment.

The Eelgrass Cultivation System at Friday Harbor Labs holds flowering heads through their process of releasing seeds, which are then collected and stored over winter.

Eelgrass Restoration in the San Juan Islands


Our restoration efforts are focused on scaling up the practices and capacity associated with harvesting, storing and planting large volumes of viable eelgrass seed. In addition, we work to facilitate the transplanting of mature eelgrass plants when possible.

Restoration through seeding has been proven in different global settings as a cost-effective approach to large scale success. Seeds are abundant each summer in “flowering heads” of the eelgrass shoot. These flowering heads are collected by hand prior to the seeds falling out and dispersing. They are transported either to a planting site while still contained within their spathe for planting through a method known as Buoy Deployed Seeding; or taken to our Eelgrass Cultivation System at Friday Harbor Labs for processing and winter storage.

Seed processing at the Eelgrass Cultivation System consists of allowing the seeds to mature and drop from their spathes into a system of holding tanks and continuous fresh flow of seawater. The ECS serves as an eelgrass nursery to cultivate as much healthy seed stock as possible, store over winter, and prep for planting the following spring. We are currently working on increasing the volume of the ECS in order to host tens of thousands of eelgrass flowering heads and hundreds of thousands of seeds, over a 10x increase from the size we have been working with since 2019.

Seeds stored over winter can be kept dormant through a cold stratification process, and also tested for overall seed viability. After winter storage, seed stock is brought to restoration sites to be planted through one of several different planting methods. These methods include dispersal seeding, injection seeding, hessian bag deployment, and seed buoy deployment.


Volunteers collect flowering heads in the intertidal zone during a summer seed harvest.

To learn more about our eelgrass restoration project, contact Mitch McCloskey at

Eelgrass Publications from our Partners

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For the DNR's Puget Sound Wide Eelgrass Restoration Website 

Click Here! 

How can I contribute?

Thank you for your interest in helping us restore our marine environment. Please contact Eelgrass Restoration Project Manager Mitch McCloskey at if you would like to contribute to eelgrass restoration.

Make a Financial Impact. The eelgrass restoration project receives state and federal funding for our efforts. Financial contributions can help take this funding further, allowing more eelgrass to be planted, and ultimately contribute to the health of our local marine environment. See our donation page here. 

Get involved. We will be seeking volunteers to help in our restoration efforts, as needed. Express interest in volunteering to or follow along as we post volunteer needs on social media (IG: sanjuanislandscd, FB: San Juan Islands Conservation District). 

Give input. We are always looking for ways to improve our project and engage the community. Reach out if you have any questions, insights, or opinions on the eelgrass restoration efforts here in the San Juan Islands. 

Recommended Reading

This project has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement PC-01J89501 through the Washington Department of Fish and Wildlife. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency or the Washington Department of Fish and Wildlife, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.

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