Volunteer River Herring Monitoring at Beaver Dam Brook and Manomet Brook

2023 Herring Count Results Are In!

The data from 2023 have been compiled and Mass. Division of Marine Fisheries has provided us with a population estimate of ~2,390. This is the highest population estimate thus far, although close to the estimate of ~2,246 in 2019. All the fish were seen at Tidmarsh #2. This was a welcome increase in abundance after multiple years across SE Massachusetts with low counts. Similar recoveries were seen at other South Shore runs including Pembroke's Herring Brook (up to ~190,000 after an estimate of ~5,800 in 2022) and Plymouth's Town Brook (~277,000 up from ~169,000 in 2022).

Other facts:

  • Volunteers counted for a total of 6,800 minutes, equivalent to ~113.3 hours or ~4.7 days!
  • The first fish were seen on April 16th and the last fish was seen on May 28th.
  • The peak 10-minute counts were on April 26th and May 4th (22 fish each); May 4th also had the highest daily count of 41 fish.
  • The total number of fish counted was 182.


Thank you to our volunteers and project partners who put so much effort into documenting the recovery of herring in Beaver Dam Brook.



By Sara P. Grady
October 31, 2023