Over the course of 22 events from June through September, 835 volunteers helped clean up the Mystic River by partnering with the Mystic River Watershed Association (MyRWA). Working from canoes volunteers removed the invasive plant, water chestnut, by hand. More than 134,800 pounds of plant material were removed from the Mystic River in Medford and Somerville as well as the Arlington Reservoir.

Native to Asia, Europe and Africa, water chestnut thrives in the nutrient rich waters of the Mystic River Watershed – in some places extending nearly shore to shore. This vegetative mat impedes boating, fishing, and swimming and crowds out native plants. Additionally, the decomposition of large quantities of water chestnuts lowers dissolved oxygen, which can lead to fish kills.

“The invasive water chestnuts have been quite a headache for our rowers,” said Rich Whelan, Program Director of the Gentle Giant Rowing Club, who practices on the Mystic River in Somerville. “As they multiply, the lanes of travel on the Mystic narrow and even the slightest misjudgment in course can cause the chestnut plant to become tangled in our oars which has the possibility of causing a rowing shell to flip. The work the Mystic River Watershed Association has done to remove them from the river has allowed us to continue rowing not only productively, but safely.”

The Mystic River Watershed Association has partnered with boat clubs, municipalities, local corporations, the Massachusetts Department of Conservation and Recreation, Massachusetts Water Resources Authority, Charles River Canoe and Kayak and community volunteers to tackle water chestnut since 2010. Progress is also being made to manage water chestnut through a mechanical harvester. Funding for this year’s work has been provided by National Fish and Wildlife Foundation, Massachusetts Water Resources Authority, Rockland Trust, Wynn Boston Harbor, Riverside Yacht Club, Mystic Wellington Yacht Club and the City of Medford.

“We are fortunate to work with many partners in this effort and continue to see progress year after year,” said Patrick Herron, Executive Director of the Mystic River Watershed Association. “Removing water chestnut is not only a fun way to experience the Mystic, but has meaningful impact on the health of our local river.”

The Mystic River Watershed Association thanks the community volunteers who supported this effort, as well as the following companies and organizations that sent groups of volunteers in 2016: