Electronic counter installed at Harwich herring run
High-tech device is the first to measure herring from Nantucket Sound
Cape Cod Times
By Doug Fraser
Posted Mar. 20, 2016 at 2:00 AM
Updated at 7:17 AM
HARWICH — Last week, workers from the state Division of Marine Fisheries and the town installed the Cape’s first electronic fish counter on the Herring River. The state now has these counters at four sites and there are nine additional devices maintained by private organizations at other fish runs, said Brad Chase, DMF director of the state’s anadromous fish program.
“Our goal is to get one high-tech counting station at every major area,” Chase said. The Herring River counter is the first one on Nantucket Sound.
The principle behind the counter is relatively simple. Fish are funneled into a narrow passage that resembles an old ear trumpet, allowing just one herring at a time to pass through, breaking an electric current that sends a signal to a counter documenting each fish as it heads upstream to spawn. There are eight counting tubes spanning the fish run at the Herring River to help ease the backup when there is a big pulse of fish.
The electronic monitor is expensive — around $15,000 for the one in Harwich — Chase said. The DMF staff knocked back the cost by fabricating the specialized housing that conformed to the dimensions of the Harwich run in their own shop.
While video counters are less expensive, their recorded video images have to be reviewed manually to get the count, driving up the actual costs to get the data.
Chase said electronic counters will improve the accuracy of population estimates since they keep track of fish around the clock as opposed to human counters who are on duty for only brief spans of time. He said the accuracy of the electronic counters is checked regularly against visual counts.
— Follow Doug Fraser on Twitter: @dougfrasercct