For the first time in generations, herring have returned to Horn Pond in Woburn.
Since early May, river herring - ocean fish that return every year to fresh water - have been swimming up the rock spillway at Scalley Dam.
They are easily viewable from Lake Avenue at the bottom of the structure and this migration in the Mystic River system involves hundreds of thousands of fish and will be ongoing through the early part of June.
River herring include two species of herring, Blueback herring (Alosa aestivilis) and Alewife (Alosa pseudoharengus). These two species are referred to as “anadromous” fish as they live the majority of their life in salt water but lay eggs or spawn in fresh water. The millions of river herring eggs that are produced in Horn Pond will develop into juvenile herring within just a few days
In the past few years, fish ladders that allow herring to get past dams downstream at Center Falls in Winchester in and at the Mystic Lakes have been built. As a result, Alewife and Blueback herring can travel from the Atlantic Ocean up the Mystic River, the Aberjona River, and Horn Pond Brook to spawn in Horn Pond in Woburn for the first time in more than a hundred years.
Beneficiaries in Horn Pond will include many other animals that eat small fish, include sport fish such as Largemouth Bass.
“This run of fish is a testament to the value of the living system we have here at Horn Pond,” says Mayor Scott Galvin. “We are committed to our continued protection of this resource but also enhancing the spillway with an improved fishway. The return of the herring to Horn Pond brings back a vital element of biodiversity in this beautiful place.”
Since 2012, hundreds of volunteers count river herring passing through the fish ladder at the Mystic Lakes Dam in Medford to spawn in Upper Mystic Lake, organized by the Mystic River Watershed Association. Counters have documented an increase from an estimated 199,000 river herring in 2012 to an estimated 630,000 in 2017. It is expected that those numbers will expand as new spawning habitat is now available in Horn Pond. In 2017, the river herring run in the Mystic River was the largest run in the Commonwealth of Massachusetts.
“The run of the river herring in our river system is truly a marvel of evolution and natural history that is happening hidden under our noses.”, says Patrick Herron. “The number of fish knocking up against this spillway is testament to the value that an improved fishway passage would have at this site”.
The Mystic River Watershed Association launched a new Herring Education Program in 2017 and is partnering with a dozen local schools to engage youth in this largely hidden annual migration.
Through the installation of an underwater video camera at the Mystic Lakes fish ladder, the herring migration was broadcast into classrooms where students helped document the herring migration, explore data, and learn more about these important fish.
Watershed educators visited classrooms providing hands-on science and STEM education, in addition to hosting field trips to the fish ladder.
If anyone would like to get involved and help monitor the number of herring in Horn Pond, contact Erica Wood (erica.wood@mysticriver.org).
Additional ways to get involved include helping count fish in the online fish counting program or getting involved with a variety of the other Mystic River Watershed Association activities.
The organization is dedicated to protect and restore the Mystic River, its tributaries and watershed lands for the benefit of present and future generations.
