Lake Tomah carp removal project aims at improved fishery, lake habitat
Weekly News Article Published: October 20, 2009 by the Central Office
TOMAH - In the past week and a half, thousands of dead carp have floated to the surface of Lake Tomah, the result of a chemical treatment by the state Department of Natural Resources.
From a biologist’s perspective, it is a gratifying sight and for local residents it is cause for celebration. It means this reservoir has been released from the death grip of the invasive carp. Lake Tomah has been given that rarest of gifts – a fresh start.
In two to three years this weedless mud hole will once again be a clear-water lake with rich green plants waving in soft, near-shore currents. Within five years, healthy populations of northern pike, largemouth bass, black crappies and bluegills will thrill a new generation of fishermen.
“It’s wonderful and it’s exciting,” said Ruth Nystrom, an enthusiastic lakeshore resident who helped cook lunch for work crews on treatment day. “It’s going to be clear and the fishing is going to be good. It’s going to be a real asset for Tomah.”
Pilot Rene "Sparky" Stimart of Skyline Helicopter used his small and highly maneuverable craft to spray a mixture of water and rotenone on Lake Tomah. The spray jets created large droplets so there was no misting and the mixture fell entirely on the lake.
WDNR Photo by Ed Culhane
Much of this excitement was highlighted by the low-flying helicopter used to drop precise amounts of rotenone on the lake, which was captured in a new video report of the lake treatment available on the Lake Tomah rehabilitation project page of the DNR Web site.
In the meantime, Jordan Weeks, the DNR fisheries biologist who headed up the project, said the floating carp tell what happened to this lake.
Within an hour after treatment was completed, dead carp began surfacing in the shallows. Their small, uniform size revealed stunted growth. They had destroyed their own habitat.
WDNR Photo by Ed Culhane
“None of the carp were large,” Weeks said. “They reached a medium-small size and stopped growing. By rooting up every vestige of aquatic vegetation they had destroyed the habitat so thoroughly that even the famously hardy carp could not thrive.”
The decaying population of harmful invaders will soon disappear, with a good deal of help from flying scavengers.
“The seagulls are going to be too fat to fly this winter,” observed Joe McDaniel, chairman of the Lake Tomah Committee.
Years of planning and weeks of precise calculations and detailed logistics preceded treatment day, Oct. 8, when more than two dozen DNR employees took up stations around the lake and along stretches of the Lemonweir River which carries water to and from the reservoir. Carefully measured doses of rotenone, an organic pesticide, were used to kill all fish in the lake. The chemical does not harm birds or mammals.
Fortunately, few game fish were affected because there were few game fish left in the lake. The DNR lifted all size and bag limits this past spring.
“I think the fishermen did a pretty good job this summer of cleaning it out,” McDaniel said. “Everything you see floating is carp, and there are thousands of them.”
Much work is left to be done. The lake will be kept three feet below normal elevation until late summer 2010 to allow aquatic vegetation to take root.
“The weed beds are out there,” McDaniel said. “They just weren’t able to grow because of the carp.”
The city will dredge out the sediment basin at the mouth of the Lemonweir so that silt falls out before it flows into the lake. Monroe County will bring in tons of rock to stabilize the small islands in the lake and to create off shore reefs to attenuate the erosive action of waves and boat wakes.
A new handicap accessible fishing pier will be erected over one of the lake’s best fishing holes. More than three dozen felled oak trees will be anchored offshore to create underwater structure and habitat, something for invertebrates to hang onto. DNR will begin stocking game fish and set regulations to allow a first-class fishery to develop.
“It’s been a busy project, working with the state,” said Ken Patterson, the city’s director of public works and a key member of the planning team.
Bryce Richardson, soil and water conservationist for Monroe County said much of the island restoration and rock work will begin this winter. Eventually, stinging nettle and canary grass will be replaced by more beneficial native plants.
As the operation was set to begin DNR fisheries biologist Jordan Weeks went over safety procedures with Scott Humrickhouse, director of the DNR West Central Region.
WDNR Photo by Ed Culhane
“The coordination went well between the agencies,” Richardson said. “It was fun to be involved with it. As far as I can tell, everything is going according to plan.”
Weeks said it will take about four years to re-establish a fishery. With luck, he said, the lake won’t need another rescue for at least a half century.
“Thanks to all the help we got from the different groups, it went as well as it possibly could have gone,” Weeks said.
DNR watershed expert Patrick “Buzz” Sorge, who helped the city obtain grants for the project, credited McDaniel for revitalizing the lake committee and generating the social will to take on such a dramatic project.
McDaniel said when folks would complain about the upcoming treatment, he’d ask them how many ice shanties they saw on the lake in recent winters. The answer – hardly any. Back in the day, he said, Lake Tomah supported a village of ice fishing shacks.
In a few short years, McDaniel said, a new fishing village will spring to life.
FOR MORE INFORMATION CONTACT: Jordan Weeks (608) 785-9002 or Ed Culhane, DNR West Central Region public affairs manager (715) 839-3715
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