Note: "Researchers are able to net walleye while letting other species such as northern pike, steelhead, muskellunge and brown trout float away and recover." I wonder what the size range of the muskies were? Anyone know Frank Kolson to ask him?

1,000-volt shocks help DNR research river walleye in U.P.

<url url="[Permission to view this media is denied]
"><link_text text="[Permission to view this media is denied] … 8804300333">[Permission to view this media is denied]

04/30/08

PARADISE — As winter runoff floods Upper Peninsula rivers, researchers say they're using an electric shock to stun and catch walleye in one waterway to learn more about their spawning habits.

The base of the Tahquamenon River's Lower Falls offers ideal spawning conditions for walleye, with melt-off water bringing temperatures toward the optimum range of 42 to 48 degrees, researchers say.

"There's fast water and the right substrate," state Department of Natural Resources researcher Frank Kolson told The Evening News of Sault Ste. Marie. "There is good oxygen and enough current to keep the eggs from getting silty."

The waters are far too fast and discolored for visual observation, so DNR researchers use 1,000 volts of direct current.

Researchers are able to net walleye while letting other species such as northern pike, steelhead, muskellunge and brown trout float away and recover.

The study of spawning fish that continued last week had brought in hundreds of walleye.

"We take a cross-section (of the fish) and we can read the rings," said researcher Jim Waybrant. He compared the process to counting rings on a tree, saying it offers an accurate age count.

Kolson said the purpose of the study is to give the DNR with an accurate estimate of the mature walleye in the system.

Biologists haven't been able to distinguish the different walleye populations. Some stay in the river system all year, while others return to Lake Superior after spawning.

There is some evidence that natural spawning is taking place at this location, but officials haven't been able to say for sure.