Eelgrass Restoration

eelgrass (Zostera marina) serves as essential habitat for juvenile bay scallops, that we grow annually in the millions at MV Shellfish Group.

Since 2018, the MV Shellfish Group has been working on various eelgrass restoration initiatives both in the hatchery and in experimental restoration sites in Vineyard ponds. Eelgrass restoration initiatives at MVSG include rehabilitation of uprooted shoots found in harbors and on beaches, and annual seed propagation in the hatchery. MVSG has been experimenting with various methods for replanting both shoots and seeds in Lagoon Pond, Lake Tashmoo, and Menemsha Pond. The MVSG hatchery has become well-equipped for processing and propagating thousands of eelgrass seeds with innovative seed-holding tanks at the Hughes Hatchery & Research Station in Oak Bluffs, and plans to incorporate more seed-based restoration initiatives in tandem with shoot-based restoration.

In March of 2023, a pot of eelgrass germinated from seed two years prior entered its next stage of life as it produced flowering shoots with warming spring temperatures. As we refine propagation methods and continue to learn from our growing seagrass nursery, our goal still remains to help re-establish eelgrass beds in island salt ponds for bay scallop habitat.

Importance of Eelgrass:

Eelgrass (Zostera marina) beds serve as crucial habitat for the bivalves we invest our time in, particularly bay scallops. With its spreading rhizomes and dense blades, eelgrass is able to protect shallow areas against erosion and produce a more stable substrate, thus creating habitat for shellfish and many other animals. Like bivalves, eelgrass increases water clarity and nutrient filtration by trapping fine particles, while also sequestering greenhouse gases. Without the protection and ecosystem services eelgrass provides, the future of our reared shellfish is much more uncertain, making this a project we have a clear vested interest in.

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collecting eelgrass:

We gather eelgrass that has already been uprooted; whether it be from boat anchors, wave action, or other natural causes. We collect them from shallow water along the shore, boat landings and harbors. Menemsha Harbor here on Martha’s Vineyard is a hotspot for full, uprooted eelgrass plants. In addition to collecting from Menemsha, we also collect eelgrass from Tashmoo, Edgartown Great Pond, and Moshup beach on the island to increase genetic diversity. These plants may drift around with currents and winds but will never re-plant themselves. By collecting washed ashore eelgrass, we minimize resources needed to harvest the eelgrass, and restore the uprooted plant’s ability to provide for the ecosystem once again.

restoring eelgrass:

Ongoing restoration initiatives include experimenting with various replanting methods of shoots and seeds in our two experimental eelgrass restoration sites in Lagoon Pond and Lake Tashmoo. Every pond system, with their varying dynamics and characteristics, requires a different planting method to successfully re-establish eelgrass. in 2025, MVSG focused more on seed-based restoration and was able to replant 38,000 eelgrass seeds into Lagoon Pond and Lake Tashmoo with various methods learned from colleagues in the region.