A big part of what makes Cape Cod's Wellfleet Bay such a productive ecosystem is a mix of fresh and salt water. In the northern part of the Harbor, the Herring River teems with life during the warmer months, but the estuary's productivity has actually been compromised for over 100 years. Now state and federal agencies, environmental groups, local shellfishermen, and concerned citizens are working to restore this important waterway.
The upstream portion of the Herring River was blocked by a dike in 1909 to reduce the mosquito population. The result was not the hoped-for reduction of mosquitoes, but an ecological disaster that led to a collapse of one of the Cape’s largest herring runs, as well as the contamination of oysters and other shellfish. Invasive species such as European phragmites eventually took over the vast expanse of marshland, acidifying the peat and limiting the ability of the marsh to absorb carbon and withstand flooding. Nursery areas for numerous fish species were also blocked or destroyed.
Now, a $70 million project is underway to restore the natural tidal flow of the river and rebuild the marsh in what will be the largest estuarine restoration project in the Northeast.
Explore New England visited the river in 2020 to film a segment with Bob Prescott, Director Emeritus of the Mass Audubon Wellfleet Bay Wildlife Sanctuary. Prescott spoke about the history of the dike and the massive task that lay ahead to restore the river and surrounding marshland.