Massachusetts Seagrass Restoration Database
The goal of this Seagrass Restoration StoryMap is to inform and facilitate future seagrass restoration efforts in Massachusetts (and beyond) by compiling relevant information in a single database.
Below is a summary of eelgrass (Zostera marina) restoration efforts in Massachusetts, based on information collected from 12 seagrass practitioners using a combination of phone interviews and online surveys conducted in 2019. We gathered information on project location, source populations, methodology, acres restored, project success, and current status (when available). The first section features a map depicting the locations of all seagrass restoration projects in MA, including information on date, area, method(s), initial success, and current status. The second section includes visual depictions and written descriptions of the different seagrass restoration methods, with links to further information. The third section includes a map of all seagrass beds that were used as source populations for restoration projects in Massachusetts.If you know of any restoration projects not represented in this database, please contact Dr. Randall Hughes < rhughes@northeastern.edu >.
Restoration Projects
Methods of Restoration
Burlap disks
AKA tortilla method
20 holes are punched into a disk of burlap fabric in two concentric circles of 10 holes each. Each eelgrass rhizome is threaded in through an outer hole and out through the corresponding inner hole, so the leaves and the end of the rhizome both come out the top of the disk.
The disk can then be buried in the sediment at the restoration site, and will serve to anchor the woven rhizomes to the seabed until they have rooted. Eventually, the burlap will biodegrade.
Horizontal Rhizome Method (HRM)
A pair of eelgrass rhizomes are aligned parallel, with their shoots on opposite ends. The pair is pushed 1-2 cm into the sediment, and a bent bamboo skewer is used to anchor the two rhizomes in place. The bamboo skewer, similar to the burlap, will eventually biodegrade.
Transplanting Eelgrass Remotely with Frames (TERFs)
The TERF method allows a large number of eelgrass rhizomes to be anchored to a single foundational element: for standard TERFs, this is a wire frame with several weights on either side; in a modified TERF, this may be a wire or twine grid with a PVC frame.
Pairs of eelgrass rhizomes are affixed to the bottom of the frame using biodegradable paper ties. When the TERF is placed on the seafloor, the side with the rhizomes is facing down. The frame and ties both hold the eelgrass in place and prevent disruptive burrowing by crabs, giving the eelgrass the time needed to root.
Standard TERFs can be lowered off the side of a boat or placed on the seafloor by a pair of divers; modified, lighter-weight TERFs may need to be anchored with spikes in order to stay on the sediment. Both types only need to be set on top of the seafloor, rather than buried. After 3-5 weeks, once the ties have dissolved, the frame can be collected from the site.
Clump planting
This method involves digging up a clump of eelgrass from a healthy site and replanting the bundle of rhizomes and roots at a restoration site. Each clump, or sod, typically contains 5-15 shoots, some of which may be growing off the same rhizome(s).
Seeding
Though eelgrass grows rhizomes which generate new sprouts, it can also be grown from seed like other vascular plants. The projects in this database that used the seeding method all spread the seeds by hand, but other methods for dispersal have been utilized as well, such as buoy-deployed seeding and burying seeds with a mechanical seed planter .
Restoration Source Sites
Each pin represents a location identified by survey respondents as a source for a restoration project. Some pins may represent different locations in single seagrass bed.
