The herring season is over.
Commercial fisherman Steve Dahl’s 18-foot steel skiff, pulled from the Knife River Marina in early December, sits on a trailer in his yard. A thin veneer of ice still clings to its gunwales. He fished the season right to the end.
Fishing was good.
“This fall, I was almost overwhelmed,” said Dahl, 64, of Knife River. “You’re doing 600, 700, 800 pounds a day. It wears you out.”
But the previous two falls were not so good, Dahl said. Fisheries biologists say Lake Superior’s herring population is in decline. They are not sure what’s causing the population to decrease, but they believe that an increase in predators and a warming climate may be factors.
The short answer is that not enough little herring are growing to maturity. Herring recruitment — young herring that become eventual spawners — has become more sporadic in recent decades, biologists say.
“I think we still have a lot of herring, but the trajectory of the population is what’s giving us pause,” said Dan Yule, a fisheries scientist at the U.S. Geological Survey’s Great Lakes Science Center in Ashland. “A lot of surveys suggest we are in decline.”