Biggest Year Ever for the Herring Run in the Mystic River

The numbers are in!  An estimated 789,000 fish made the annual journey from the ocean to Upper Mystic Lake to spawn, according to numbers released by the Division of Marine Fisheries. This makes 2019 the biggest year for the Mystic herring run since counting started in 2012.

This year’s data is the latest installment in a remarkable ecological restoration story. Every year, two species of river herring—Alewife and Blueback herring—make the stressful journey from ocean to freshwater to spawn, all up and down the New England coast, as they have done for centuries. But they have been overfished at sea, and dams on rivers have stolen their inland breeding habitat, including within the Mystic River watershed. In 2012, a fish ladder opened up points upstream of Lower Mystic Lake for the first time in 150 years. The result, based on annual counts, has been that the population loyal to the Mystic River has more than tripled.


 “What makes the herring population recovery such a great and unique ecological success story is that it is happening in the most urban watershed in New England,” said Patrick Herron, Executive Director, Mystic River Watershed Association. “How cool it is that urban centers and healthy ecosystems are not mutually exclusive. If we can triple the population of herring through better fish passages and improved restoration, then there are many other environmental issues we can tackle successfully.”

To document the herring migration, the Mystic River Watershed Association (MyRWA) runs a successful volunteer led monitoring program. More than 160 volunteers went weekly to count herring in 10 minutes blocks from April through June.

 “I use the Mystic River data as an example on how to conduct visual counts. You are one of the few groups that adhere to the recommended protocols consistently year after year," says John Sheppard, Research Biologist at the Massachusetts Division of Marine Fisheries (DMF).

 In 2019 the Mystic River Watershed Association also monitored for river herring at Horn Pond, upstream from Mystic Lakes. Despite struggles to make it past Scalley Dam, an estimated 10,000 herring made it into Horn Pond. The City of Woburn, DMF, and the Mystic River Watershed Association are committed to improving this fish passage. The data shows that herring are now able to make it past Center Falls Dam in Winchester in large numbers, and opening up Horn Pond as spawning habitat would be a major next milestone.

 “If we restore habitat and keep our water clean, life will fill it,” said Andy Hrycyna, MyRWA Watershed Scientist. “I am excited to continue this trend for river herring in the Mystic.”