Redhorse suckers floated up by the dozens as the electroshocking boat passed. Even I, standing well above the rushing Kankakee River on Wilmington’s North Island, could pick out the redhorses.

When the electroshocking crew — biologists Rob Miller, David Wyffels and Tristan Widloe — came back from collecting walleye for brood stock downstream of the Wilmington Dam, I asked for a rundown of fish seen.

Rob Miller drives the boat while David Wyffels and Tristan Widloe (bright waders) net walleye Wednesday during collection of brood stock on the Kankakee River below the Wilmington Dam.
Credit: Dale Bowman

Widloe rattled off smallmouth bass, redhorse (silver, golden, river, shorthead), northern hog suckers, common carp, quillback suckers and a small flathead catfish.

I don’t know Widloe, so I wasn’t sure if he was messing with me with his confident distinction of four redhorse. So I asked Miller and Wyffels, whom I know, if such a distinction could be made simply by seeing them float past.

They assured me it could, especially by someone such as Widloe, who has seen and handled thousands of redhorse and has become an aficionado of the suckers.

Widloe even dug up the ideal spawning temperature for shorthead redhorse (47 degrees) for me. He noted, however, the reason redhorse were there probably wasn’t related to spawning but because the habitat was right.

The Kankakee is special that way. The river redhorse is threatened in Illinois because of habitat degradation, and the Kankakee is a rare place where they are seen regularly.

I am still impressed by Widloe’s ID skills. Anytime I catch a redhorse, I take photos before releasing it, then try to identify the species when I get home.

As special as the Kankakee is, it has some habitat issues, primarily related to the sand load rolling downstream from Indiana. That’s why I was there: to watch the collecting of brood stock for the walleye-stocking program.

The tons of sand rolling downstream greatly reduced spawning of walleye.

In 2000, the Illinois Department of Natural Resources started an innovative stocking program. Brood stock were collected from the Kankakee, then taken to the LaSalle Fish Hatchery. There they were stripped of milt and eggs, then returned to the Kankakee. The eggs were hatched, then the young were stocked in the Kankakee.

I didn’t like the idea initially because I thought that if nature was saying walleye couldn’t survive in current conditions, why try to force it? But the program turned out to work well without messing up the ecological balance of the river, and the DNA of the native walleye is being preserved.

As the biologists set up Wednesday, Wilmington fisherman Charlie Friddle waded out and found 44 degrees. Miller said the water ideally would be closer to 50 to catch the peak of the spawn.

Nature is interesting when it comes to spawning.

When the crew came in, they had 15 walleye, nine of them females. The biggest topped 6 pounds. Cold water or not, one female was already spent (dropped her eggs).

‘‘Some come early, some come late,’’ Wyffels said. ‘‘We want the ones in the middle.’’

There was enough time to electroshock below the Kankakee Dam. Miller said they rarely collect females there, and that held again this year. Of the eight walleye collected there, only one was thought to be a female.

Why the difference for collecting females below the Kankakee and Wilmington dams?

Tristan Widloe transfers walleye from the collection boat to the aerated tanks for transporting to LaSalle Fish Hatchery Wednesday during collection of brood stock on the Kankakee River below the Wilmington dam.
Credit: Dale Bowman