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April 25
MyRWA Earth Day Cleanup, 9AM-Noon
MacDonald Park, Medford

April 25, May 2, May 9
Mystic Community Earth Day
Various locations

May 12 *Note date change
Committee Meeting, 7-9PM
Tufts University, Lincoln Filene Center, Rabb Room

 May 17
Mystic River Herring Run & Paddle, 9AM
Blessing of the Bay Boathouse, 32 Shore Dr., Somerville



MyRWA launched the fourth year of the Herring Monitoring Program on April 8, 2015. The data is used to estimate the total herring run size in the Mystic River and is shared with the Massachusetts Division of Marine Fisheries to help inform trends across the State.  MyRWA would like to thank the DCR, Medford Boat Club and of course all the monitors for supporting this program!



Herring is a type of fish. The Mystic River Watershed supports two species of herring: Alewife (Alosa psuedoharenous) and Blueback Herring (Alosa aestivalis). Both species, collectively called river herring, are anadromous. This means they spend most of their lives at sea and return to rivers—like the Mystic—to spawn, or lay their eggs.



In colonial times and earlier, herring in the Mystic River were extraordinarily abundant.  But from the 1900’s until today a much smaller population of river herring is present. Since the dam has been rebuilt this is the first time that a fish ladder will be in place to allow an accurate count of herring.

According to the Herring Alliance some river herring runs on the Atlantic Coast have declined by 95% or more over the past 20 years. In 2006 the National Marine Fisheries Service designated river herring as a species of concern. Population decline may be associated with numerous factors including by-catch, habitat loss and degradation, water pollution, poaching, access to spawning habitat, and natural predators.



The Herring Monitoring Program will monitor herring swimming through a fish ladder to estimate run size. Counting will occur from April 1 – mid June following the Division of Marine Fisheries protocol.

The goal of the herring monitoring program is to collect valuable data about herring populations as they make their way up the Mystic River to reach their native spawning grounds and to educate the public about river herring.  We hope that through participation, volunteers will increase their understanding and stewardship of the Mystic River and the watershed.

Volunteers monitor river herring at the Mystic Lakes Dam fish ladder, counting fish and collecting data to estimate run size in the Mystic River. Previously the dam prevented river herring from reaching their native spawning grounds. In the past, a bucket brigade was assembled to hoist the fish over the dam. Thanks to the Upper Mystic Lake Dam Rehabilitation project, a new fish ladder allows passage for river herring.



2014: 31,063 herring were counted from April 1 through June 26, 2014. Using modeling software provided by the Division of Marine Fisheries, the Mystic River herring run was estimated to be 239,059 +/- 37,288 herring.

2013: 23,635 herring were counted from April 1 through June 26, 2013. Using modeling software provided by the Division of Marine Fisheries, the Mystic River herring run was estimated to be 193,125 +/- 24,250 herring.

2012: 21,052 herring were counted from April 1 through June 23, 2012. Using modeling software provided by the Division of Marine Fisheries, the Mystic River herring run was estimated to be 198,932 +/- 18,062 herring. This was the first year of the Mystic River Herring Monitoring Program.



Volunteer to be a fish monitor!  No previous experience or knowledge is required. To find out more about this volunteer opportunity or the project, please email:



MyRWA also monitors American Eel (Anguilla rostrata) passing through the Upper Mystic Lake Dam. Read more about eel monitoring here.


This program would not be possible without the support and collaboration with:



CLICK HERE for 2015 Herring Monitoring information





Click to enlarge

Click the image below to identify herring.




More than 90 volunteers signed up to be part of the 2015 Herring Monitoring Program, which began on Wednesday, April 8th. If you have any questions about the program, please contact


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