Luck would have to be in the air – and the water – for a river herring to come swimming below the footbridge right now and be counted.
It was a sunny, warm mid-May day along the Shawsheen River between Stevens and South Main streets. Birds sang. A few families walked nearby. Children ran in circles.
Below the aged footbridge, Emerson College biology professor Jon Honea, an Andover father originally from Arkansas, went knee deep in the water and scrubbed algae from metal panels on the river's bottom.
The recycled street signs contrast with the herring – alewife and blueback – making them easier for volunteer fish counters to see.
This year, 2020, could be a watershed one. For the first time in centuries, mature river herring that were spawned here and moved to the ocean will perhaps return to where they entered the world as hatchlings.
They arrived in 2018 as the progeny of newcomers who ventured here after the Balmoral and Marland Place dams came tumbling down, removed, in part, to allow the return of native species.
So far fish numbers are few. Only seven had been counted as of May 14, three of them by Jane Cairns and her daughter May 11.
"It was exciting," said Cairns, a counter for all three years.
There were 500 and 1,500 counted the past two years between April and June. But there is still about a month of counting left.
Herring numbers have declined over the past two springs in many of the state's more than 100 herring river runs; and this spring there are fewer volunteers to count them at the Shawsheen site.
"This year we have about a dozen counters," Honea says. "Usually we have about 300, but not as many folks are out and about this year."
For the first time, the volunteers are using their smart phones – instead of a communal clipboard – to register findings, an online survey designed by Andover High School teacher Seema Gupte.
Another health precaution this year is a digital thermometer that automatically registers the water temperature. Honea installed it. No more need to plop a thermometer in the water and read it. Today the temperature is 55 degrees, just the way fish like it.
The runs of foot-long river herring were once so great in New England waters that lobstermen baited traps and farmers fertilized fields with them.
The fish are said to be delicious — and not just to humans. They are critical items on the food chain, eaten by striped bass, bluefish, osprey and eagles as the herring swim from the Shawsheen to the Merrimack to the ocean and back.
A female lays hundreds of thousands of eggs, but only one or two make it back to spawn. It's these fish Honea and the other spotters seek.
Thousands of them have been counted downriver at the Lawrence fish elevator on the Merrimack and some may be Shawsheen bound.