Salem Sound Coastwatch completed the eelgrass field germination experiment for the WHOI Sea Grant project, “Modeling and piloting a new seed-based approach to large-scale eelgrass restoration in Massachusetts,” a study with the Massachusetts Bays National Estuary Partnership (MassBays) and the MA Division of Marine Fisheries (DMF). For this study, the team investigated the timing of eelgrass flowering and seed production, the impact of seed-harvesting on donor beds, and the viability of harvested seeds. In addition to these studies, we also investigated the germination success of seeds planted in the field. In September 2024, over 3,000 eelgrass seeds were planted off of Winter Island in Salem, MA. These seeds were planted within two different treatments – either contained in burlap pouches or planted directly in the sediment as a control. The eelgrass seeds were then allowed to germinate over 8 months, from September 2024 to June 2025.
Early this summer, the burlap pouches and the control plots were removed for analysis. With help from volunteers, the number of germinated shoots and recovered ungerminated seeds were counted. This involved sorting through sediment, shell, and other debris to locate the eelgrass shoots and tiny seeds from each study plot. Overall, we found that seeds had more success germinating when they were protected in burlap, rather than planted directly in the sediment.
Salem Sound Coastwatch and the MassBays team hope to use this information for future eelgrass restoration efforts, including a pilot restoration project in Beverly this fall. This week, over 20,000 eelgrass seeds will be planted in biodegradable bags in the waters off of Dane Street Beach and Lynch Park. Volunteers will help in this effort by assembling the planting bags, while SSCW staff snorkel to stake them to the seafloor. We look forward to tracking the growth of eelgrass in this area!