Tracking River Herring

A new electronic tagging program has debuted on the Coonamessett River in Falmouth, MA in hopes of answering questions on the migration of river herring.

This year, volunteers from the Coonamessett River Trust (CRT) are aiming to tag 400 river herring and track their spawning migration throughout the river system. Last week I volunteered to help out, and had the opportunity to participate and learn more about this unique project.

Corralling and netting of river herring
First we netted the herring, using two large seine nets, at a run where they first enter the river from saltwater.

we only came up with a couple of little pond shiners
Our first attempt didn’t go as planned, and we only came up with a couple of little pond shiners.

netted herring
On our second attempt, we hit the jackpot. Over 100 herring were balled up in the net. A long-handled dip net was then used to pass the herring, one at a time, to the biolgist who was tagging the fish.

Small incision for tracker insertion
The first step in the tagging process is to scrape away a few scales, and make a very small incision in the belly of the fish with a scalpel.

recording the tag number
Next the tag number is recorded with a handheld device.

Closeup of passive instrument transponder
The tags, called passive instrument transponders, or PITs, are about the size of a pill.

The tag is quickly implanted into the body cavity of the fish.
The tag is quickly implanted into the body cavity of the fish.

Measurement and sex determination
They are then measured, and their sex is determined.

Recording data
The tag number, length, sex and species (alewife or blueback) are then recorded, later to be added to a database.

The herring are then released back into the river
The herring are then released back into the river. Of the 60 fish we tagged that day, all seemed to happily swim away.

Several counting stations have been strategically placed along the river. A wire is strung across the river at each location. Every time a tagged herring passes under the wire, data will be be recorded. These counting stations were made available by Dr. Heidi Golden, a biologist at Marine Biological Laboratory in Woods Hole, MA. The equipment was purchased to study the migration of grayling in Alaska. Since she doesn’t do her research there until late summer, she has donated her equipment to help learn more about the spawning habits of the Coonamessett River herring.

Tagging the herring will help the researchers better understand where they travel within the river system. Aside from the river itself, there are three potential ponds where herring can spawn along it’s 3 mile stretch. It is currently unclear where the main spawning area is. This information will assist in efforts to identify and make passage improvements.

Culvert trapping herring
Humans have modified the river for centuries with mill construction and cranberry cultivation along it’s banks. Numerous culverts and barriers exist as a result of these activities. Some of these structures restrict fish movement and degrade habitat by modifying flow, raising water temperatures and degrading streambed characteristics.
The researchers also hope to learn a great deal about the survival rates of the fish during the spawn.

The public can participate in this effort by “adopting” a fish for $10 each or three for $25. Donors can name their fish, and at the end of the season the trust will be able to tell each person when their fish was tagged, where it went, and when it left and headed back to the ocean.
Those interested in adopting herring, or volunteering to count them, should contact Charles Cooper at or Lou Turner at

3 on “Tracking River Herring

  1. chris

    Great project, nice write up ! Saw some herring this weekend in the Boston area and they weren’t alone 😉

  2. richard b martin

    So happy to see such concerted efforts being made to sustain habitat for the herring, and all sea creatures for that matter! From the sea we may have come, but so much depends upon the sea and it’s bounty, that should we forsake it and not protect it, I would expect we would have no choice but to follow the seas to our demise. Thanks to all the volunteers, and technical support that sustains the effort to “DO THE RIGHT THING”! Kudos! But what does a 56 year old bus driver from Boston need be concerned about some little fishes ? I’ll tell you why I am concerned. I am a grandfather who would like to teach his 2 Autistic grandsons how to fish. As well as another grandson and two granddaughters ! So, we are going to need a great supply of fish if my calculations are correct ! And maybe, A couple of marine biologists in the making. thank you all …..

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