Wicked Local Medford
July 13, 2014
Medford citizen scientists monitor 2014 herring migration
The 2014 herring migration was tracked by more than 90 volunteer herring monitors at the DCR Upper Mystic Lake dam in Medford as part of the third year of the Mystic River Watershed Association’s Herring Monitoring Program.
This baseline study provides valuable information to marine biologists who are studying river herring, referring collectively to two similar species — the Blueback and Alewife herring — in one of the commonwealth’s largest urban watersheds.
The monitoring program takes place at the Massachusetts Department of Conservation and Recreation dam between the Upper and Lower Mystic Lakes, which span Winchester, Medford and Arlington.
Trained volunteers stand over the fish-ladder at the dam, installed in 2011, to count the herring as they make their way to the Upper Mystic Lake to lay eggs (or spawn). The Massachusetts Division of Marine Fisheries analyze the data collected to provide an estimate of how many herring enter the Upper Mystic Lake during their spring migration.
“The Herring Monitoring Program draws volunteers from Medford, Winchester, Somerville, Arlington and other communities to the Mystic Lakes to witness this powerful sign of spring,” said Beth MacBlane, outreach coordinator for the Mystic River Watershed Association. “We see families monitoring together and great enthusiasm and dedication from our volunteer monitors.”
This season 31,296 herring were observed, for an estimated run size of 239,059 +/- 37,288 herring in the Mystic River. These results suggest the number of river herring entering the Upper Mystic Lake may have increased slightly in 2014.
Monitoring river herring is especially important in light of the species’ recent population decline. Over the last decade, coastal landings of both river herring species averaged a little more than one million pounds — indicating a decline of more than 98 percent when compared to averages from 1950 to 1970.
Between 2000 and 2010 Alewife counts in Massachusetts’ Monument and Mattapoisett Rivers — two of the state’s most significant herring runs — plummeted almost 85 and 95 percent respectively.
River herring population decline is associated with many factors including pollution, by-catch (unintentionally caught fish), lack of spawning habitat, habitat degradation, and dams.
In April, river herring — after traveling hundreds of miles from the northern Atlantic Ocean — make their way up the Mystic River to spawn. Before the new dam, efforts like the Mystic River Watershed Association’s Bucket Brigade allowed herring to enter the Upper Mystic Lake.
The fish-ladder, a step-like structure that enables fish to pass through the dam, provides access to an additional 165 acres of prime spawning habitat and allows Mystic River Watershed Association volunteers the opportunity to conduct an accurate count of river herring in the Mystic.
This data will become an important baseline determining critical herring trends and learning more about habitat conditions.
The Mystic River Watershed Association would like to thank the many volunteers who participated in the herring count and the Medford Boat Club. This program would not be possible without the support and collaboration with the Massachusetts Department of Conservation and Recreation and the Massachusetts Division of Marine Fisheries.