StructureSpot

LADYSMITH – The day was warm, the water temperatures hovering between 89 and 90 degrees, making it more comfortable for students from three Rusk County high schools who spent the morning up to their necks in water.

Some students in a boat mixed cement to anchor individual spruce trees to the bottom of the Dairyland Flowage while others swam or waded with trees they positioned at the sides of submerged rock piles. The rocks had been dropped through the ice along the shore during the winter.

The position of the rocks had been marked with a GPS. Those coordinates, plus some searching by students, helped locate the piles this summer. The individual trees with cement foundations would be placed between the rock piles to provide additional cover.

The idea is to provide a diversity of habitat to give minnows and small fish a place to live, which in turn will provide food for bigger fish, said Jerry Carow of the Rusk County Wildlife Restoration Association, the nonprofit group coordinating the project.

The work began three years ago when Dairyland Power Cooperative drew down the reservoir to repair a dam. The association and Dairyland Power took the opportunity to haul rocks and trees onto the dry lake bed to create aquatic habitat.

When the power company refilled the lake, they saw no reason to stop creating habitat. They just had to change their methods, Carow said. Because Dairyland Power has a five-year permit from the state Department of Natural Resources to create habitat in the lake, they decided to keep going with that work.

Since the project began three years ago, the power company has brought in about 6,400 cubic yards of rock – the equivalent of a four-mile stretch of rock three feet wide and three feet high, Carow said.

So far the project has involved the installation of about 2,000 trees. Another 500 to 1,000 could be added, Carow said.

The project involves students from Flambeau, Bruce and Ladysmith high schools during summer months. During the rest of the year, prisoners from Flambeau Correctional Center provide the labor.

Fat fish

The habitat work appears to be helping fish in the flowage, said John Thiel, senior environmental biologist with Dairyland Power.

Natural reproduction of walleyes always has been good on the flowage, an impoundment of the Flambeau River, but growth of the fish typically has been slow, he said. Now the walleyes are growing faster.

“We’ve had a 2-inch increase in the average size of walleyes we’ve collected,” Thiel said.

During the next few years, more walleyes should be moving into the legal size range, he said.

Black crappies have become more abundant and also are growing well, Thiel said. Bluegills are not abundant in the flowage but are more common now than they were, as are perch and smallmouth bass.

When the reservoir was created in the early 1950s, the power company removed trees logs and stumps along the shoreline. Officials at the time figured drifting wood might interfere with power generation.

“At the time they didn’t realize they were removing all the good fish habitat,” Thiel said. “What the lake really needs is shallow water fish habitat.”

The reservoir always has been home to big muskies, but the waterway is low on suckers, a favorite food of muskies. One potential problem was a perched road culvert on nearby Crooked Creek that may have been blocking upstream spawning movements of suckers and other fish in the spring. Officials lowered the culvert so fish could get upstream, and they plan to survey the creek later this summer to find evidence of spawning by suckers, Thiel said.

Regulations

Dairyland Power and the wildlife association had wanted to bring in heavy equipment and move some existing gravel on the reservoir’s bottom three years ago when the reservoir was drained, but the DNR nixed that idea because of mercury contamination in the sediment. The mercury came from paper plants upstream.

Thiel thought the project could have been completed without recirculating mercury in the system – Dairyland had done some testing of the sediments – but the power company lost that argument.

That decision caused Dairyland Power to change plans and downsize the reefs they wanted to build, but, with the help of the wildlife association and other community groups, fish habitat in the flowage is much improved, he said.

Summer jobs

This is the fourth summer that Charlie Coughenour, a student at Ladysmith High School, has done conservation work for the Rusk County Wildlife Restoration Association.

“It’s a lot of fun. It gives me something to do in the summer, plus I get paid,” said Coughenour, who will be a senior this fall.

Twenty-four high school students worked this summer on the project, which included fish habitat improvement, repairing erosion sites, building a nature trail and creating fishing access sites.

Students work for five weeks and earn $24 per day, plus one-half of a high school credit. The students are supervised by teachers and four college interns.

Coughenour said he has learned some construction skills in the program and it’s also influenced his career choice. He plans to attend UW-Stevens Point and study environmental science.

Knight can be reached at 715-830-5835, 800-236-7077 or joe.knight@ecpc.com.