Minnesota DNR works to tag steelhead trout on Knife River to understand population decline
A popular fish near Duluth has seen its numbers decline dramatically over the past decade.
Steelhead are a type of rainbow trout that head to the Knife River to spawn. But fewer and fewer have been making that trek in recent years.
"They've been in Lake Superior since the late 1800s. They are part of the ecosystem. They are part of the food web," said Cory Goldsworthy, Lake Superior Fisheries Supervisor for the Minnesota Department of Natural Resources.
During the spring spawn, a beautiful part of the Knife River attracts a beautiful fish.
And as steelhead make their way upstream, some are getting caught in the DNR's river trap. They are weighed, measured, and then up top, they get their tag. Then the fish are released. The entire purpose of this is to learn where they're coming from, where they're going, and why their numbers have dropped.
"Now Lauren is going to put in a pit tag injected into the back," said Nick Peterson, DNR Fisheries Specialist.
In 2016 the DNR counted 1,000 adult steelhead coming through their Knife River trap. Now, that number has dwindled to just 200 steelhead.
"Here in the North Shore we are caught in this drought-flood cycle. Where either all of our rain comes at one time, or it doesn't come at all," said Goldsworthy.
Goldsworthy believes flooding has blown out some fish habitat, and drought has limited their resources.
"Our rivers rely primarily on run-off, so if we don't get rain our rivers get really low," said Goldsworthy.
The trapping and tagging also helps determine what can be done to help steelhead. They're learning that while they can't control Mother Nature, they may be able to help the fish in other ways, and give them a chance to flourish once again.
"With our stocking program, that's our hope is that we can provide not only harvest opportunities like we have done for 30-plus years, but also provide catch and release opportunities and then bolster these wild populations as well," said Goldsworthy.
Goldsworthy said brook trout and salmon are other fish that have been impacted by weather patterns in recent years.
