Lab Joins Boston Harbor Ecosystems Network on Eelgrass Field Trip

By Liana Greenberg-Nielsen

 

What’s long, green, often underappreciated, and provides a myriad of ecosystem services to coastal communities and species? Eelgrass!

 

Zostera marina, commonly known as eelgrass or seawrack, was the focus of a field trip put on by the Boston Harbor Ecosystem Network (BHEN) on June 30th. Stone Living Lab’s Education and Engagement team was excited to attend the event with colleagues and partners from around the greater Boston area. The field trip brought us to Fisherman’s Beach in Swampscott and to Cat Cove Marine Laboratory in Salem.

 

On the shore of Fisherman’s Beach, we watched as Phil Colarusso, marine biologist at the EPA, and other brave volunteers in wetsuits dragged a seine across the bottom of a eelgrass bed. A seine is a net that hangs vertically in the water, touching the seafloor. By pulling the seine through a patch of eelgrass, researchers are able to gently collect fish, invertebrates, and other species that are living in the grass. After identifying, counting, and measuring the animals, they are returned to the ocean. Surveys like this are able to show researchers the diversity and abundance of the environment. Some highlights we saw were: pipefish, juvenile sculpin, a tiny hermit crab, and more shrimp than you can imagine. Eelgrass beds are known as a type of nursery habitat, a place where young fish and shellfish can safely grow up with a much higher survival rate. Because of this they are critical to the health and longevity of New England’s fishing industry.

 

As the tide came in, we changed locations to Cat Cove Marine Laboratory in Salem. Here, we heard from Forest Schenck (MA Dept. of Marine Fisheries) and Jill Carr (MassBays) on their work around eelgrass reproduction and restoration. Using drones, researchers were able to map the health and size of eelgrass beds along the Massachusetts coast. Forest and others from DMF demonstrated a seed sorting contraption that is able to separate viable eelgrass seeds based on their buoyancy – nonviable seeds sink to the bottom, leaving behind the viable ones. They hope that the viable eelgrass seeds can be used to replant meadows that have been lost. Scientists estimate that Massachusetts has lost about half of its eelgrass in the past 20 years. They currently estimate that there are about 19,000 acres remaining. The Northeast Regional Ocean Council has produced a helpful map that shows the current eelgrass meadows. With the collected data and research around successful eelgrass reproduction, scientists aim to be able to restore some of the declining population.

Eelgrass beds provide many ecosystem services: beds can help protect against coastal erosion, a major concern for coastal communities. Meadows absorb incoming wave action to decrease the strength and size of waves that hit shore. The plants’ roots hold onto the floor, stabilizing mud and sand that would be washed away.

Eelgrass meadows also serve as carbon sinks. Carbon sinks work by absorbing more carbon from the atmosphere than they emit. They’re often associated with forests and other land plants but the ocean is home to some of the most productive carbon sinks. Eelgrass is able to collect carbon and store it in the sediment for decades or even centuries, as long as the meadow stays intact.

 

Events like this with a focus on eelgrass increase awareness of both the benefits the plant has and the challenges it faces.  By bringing attention to the humble eelgrass and the impacts it has, hopefully more work can go into protecting and restoring the population.

 

We would like to share a huge thank you to Diana Chin and the BHEN team for organizing this insightful trip! It was inspiring and exciting to connect with folks from different organizations and backgrounds around a shared interest in coastal protection.

 

Some information for this post was found in an article by Barbara Moran for WBUR, and in an EPA report about blue carbon reservoirs – check them out to learn more about the research being done around eelgrass in New England!