As I gazed into the deep pool below the deck through my polarized sunglasses, the 4-foot-long dark gray torpedo glided smoothly over the pale sandy bottom near a school of giant catfish.
This hole on the Couderay River near Radisson, Wisconsin, is a favorite spot for lake sturgeon. Max Wolter, a fisheries biologist with the Wisconsin Department of Natural Resources, knows this because his crew had caught them here before, including in 2019, the last time I joined them for the investigation. However, knowing that a fish is there and catching it are two very different things.
In 2019, the guys first attempted to hook the sturgeon using a worm as bait. This year they went straight to a tactic that has proven to be more effective.
Fishery technicians Evan Sniadajewski and Scott Braden unrolled a gillnet – essentially a nylon volleyball net on movable poles – and waded upstream of the pool in waist-deep water. Lee Dubois, a master’s student at the University of Wisconsin-Milwaukee, pulled the huge landing net out of the canoe. Its diameter was about the same size as the circle my arms would make if I told a huge big fish story.
Wolter – standing in the back of his canoe – led a sturgeon towards the gillnet.
The fish rodeo was exciting and fast. Before I could even see a way to help, the guys had stopped the upstream sturgeon leak with the gillnet, and Dubois had picked it up safely in the dip net.
After a few screams of excitement, the tagalongs – four members of the Cable Natural History Museum and I – all waded over to Wolter’s canoe to process our first big catch.
As Sniadajewski showed us this magnificent fish, he began to express himself poetically about their adaptations. Sturgeons are bottom feeders. The whiskered barbels under their snout are coated with chemoreceptors to help them “smell” the food underwater.
“It’s probably the most sensitive part of their body,” he says with awe.
When these barbels detect food (snails, insects, leeches, crayfish and small clams), the sturgeon pushes its tubular mouth down to suck up its prey. Any gravel sucked up in the process is expelled through their gills.
We all took the opportunity to run our hands over the skin of the sturgeon, and I was amazed to find that it was rough, like the skin of a shark. Wolter also pointed out the slightly arched dorsal fin – which when we finally let it go, crossed the surface of the water like a mini jaw.
Sturgeons are fairly old fish. They evolved just as dinosaurs went extinct 100 million years ago and have undergone very few anatomical changes since then (although the 29 species of sturgeon in the world have rapidly evolved into a wide range of sizes. body to fit various niches.)
Wolter waved his portable tag reader over the sturgeon’s head. The scanner beeped!
MNR has tagged sturgeons on the Couderay River for enough years that it is more likely to find tagged fish than unmarked fish.
Since the removal of the Grimh Dam at Radisson in 2011, the Couderay now flows freely into the Chippewa River, where sturgeon populations are healthy enough to be harvested. MNR is documenting the natural recovery of the sturgeons in one of their historic haunts, now that the fish are no longer isolated by the dam.
In Wisconsin, lake sturgeon is a species of “special concern” with a regulated harvest, but sturgeons are listed as threatened or endangered in 19 of the 20 states in the original range of the fish.
Since this sturgeon was only 41 inches long and the one we caught here in 2019 was 50 inches long, we knew it couldn’t be the same fish. The guys would compare the data in the office and learn more about the movement of the sturgeon in the river.
During the day (only three miles of river) we caught three sturgeons, all with tags. We were thrilled to see these fish and to see the guys use all of their skills to catch them. It was a little disappointing for me, because in 2019 we had fished 10 sturgeon on this same stretch of river.
When I asked Wolter where the others could have gone, he cited the dry spring and said they probably went down the river, or maybe not migrated as far upstream as usual, in response to lower water levels. Recent rains have brought the river back to normal, but the fish have not followed.
I could tell these guys have a passion for fish and fishing that I can never match. Many of their days in the field include crossing overgrown streams under the constant attack of mosquitoes and horseflies.
This spectacular day on the river was a real treat – to put their fishing and fish handling skills to work in a beautiful setting. It is because of their passion – and the funding you provide through your fishing licenses – that sturgeon (and trout and bass, etc.) will only disappear deeper into a pond and not disappear. of our state.
Emily Stone is the naturalist / director of education at the Cable Natural History Museum near Hayward, Wisconsin.