Herring Coming Soon
The herring migration will start again in May 2025.
Starting in May 2025 new videos will be available and we will be calling on volunteers to document the run size. Until that time, you can check out videos from last year to practice counting or see how the system works.
Love Nature? Count Fish.
Help us track river herring populations in the Mystic River watershed, and be part of an environmental success story. Watch a video and record what you see. Scroll down for the latest data. Have questions about the online counting, check out the FAQs here.
Read instructions for more detail.
Today's Activity
Each bubble represents one video count from today. The bubble is placed at the time when the video was counted (not when the video was recorded). The size of the bubble indicates how many fish were counted in that video. Hover your mouse over the bubbles to see more information, or click and drag to zoom in.
Videos Counted Today
Total Estimated Fish Run
Each bar shows our current estimate of the total number of fish migrating each day. These totals are updated in real-time using a statistical model that estimates how many fish migrate over the entire day based the individual counts of videos recorded on that day. The error bars represent our uncertainty in the daily total (95% confidence interval).
Total Estimated Fish Run
Number of Fish Counted
Each bar shows the total number of fish that have been counted for each day (so far). These totals will increase as more videos are watched. Note that these totals tend to be much less than those in the chart above, which uses these counts to estimate the total number of fish passing over the entire day, not just during the videos that have been counted so far.
Total Fish Counted
Number of Videos
Each bar shows how many videos were recorded each day, plus how many of those have been counted and how many remain to be counted. The number of recorded videos depends on how active the fish were on that day, but also whether the camera was properly configured to only record when it detected fish and not other things floating by.
Total Videos
Counted
Total Videos Remaining