In 2008 the Department of Energy and Environment (DEE) (formerly the Department of Marine and Environmental Affairs (DMEA), and the Environmental Management Division (EMD) before that), undertook as a project the task of establishing a baseline population estimates for the number of river herring migrating upstream at Town Brook. EMD partnered with the University of Massachusetts – Amherst and the Massachusetts Division of Marine Fisheries to complete this project. EMD utilized three different methodologies to establish the population: a video counting system that ran 24 hours a day over the course of 70 days, 3 daily ten minute counts every day for 70 days along with subsequent analysis of the data, and the Smith-Root electronic fish counter. Both the video counting system and the Smith-Root system provided counting coverage 24 hours a days over the entire herring run season.

Help us track changes in river herring populations over time by counting the number of fish passing through the fish ladder at Jenny Grist Mill dam located on Town Brook in Plymouth, Massachusetts.

From April through June of each year, an underwater camera system records short videos (10 - 60 seconds long) of river herring at the Jenny Grist Mill dam.

After each video is recorded, it is immediately uploaded to this website so that folks like you can help us count the number of herring passing through the dam.

With these video counts, we then estimate in real-time the total number of herring that have migrated so far this year. Every video count matters, and helps bring us one step closer to an accurate estimate of the total herring run.

If you have not been to this site before, please take a moment to view the instructions and learn what to count and what not to count, which is important for us to collect accurate data.

If you've already seen the instructions and are ready to go, then let's start counting!