Oconomowoc, Wis. About 13 miles of the Oconomowoc River
underwent chemical treatment on Nov. 1 to remove carp that have
plagued the river, which now could become a better fishing
destination for anglers.
“During the last few months we took several canoe trips down the
system and it’s surprising how nice of a trip it offers,” said Sue
Beyler, DNR fisheries biologist for Waukesha County. “There really
are some nice fishing opportunities in there, and some of the fish
grow to a nice size. I spoke with some people who caught bass up to
It’s these nice fish that some locals were worried about, but
Beyler said the DNR has been capturing most of the game fish and
saving them for post-treatment stocking.
“Some of the fish have been in holding in Lac La Belle, and
others we placed in a pond out at Bong Recreation Area,” she said.
“Locals don’t have to worry about the fish that were in the system;
we’re putting almost all of them back. After the treatment, we
really didn’t find any large game fish that were killed.”
In fact, the DNR also is introducing more fish to the Oconomowoc
“We will be putting in northern pike up to 22 inches into the
system that we got from Big Muskego Lake, where they have too many,
at about 8.5 per acre,” Beyler said. “We’re also taking some
largemouth and smallmouth bass from other lakes in the watershed,
such as Okauchee, Pine, and Oconomowoc.”
Some residents were worried that the rotenone treatment of the
river would affect some of the fish in the lakes, but Beyler said
that there’s no problem.
“All the lakes are upstream from the rotenone,” she said. “We
then detoxify the water before it would enter the Rock River in
Jefferson. We’ve already restocked the game fish back into the
river and everything is doing fine. These treatments, especially in
a river, don’t affect the system for too long.”
The carp in the system have been controlled by an electrical
barrier that keeps them from getting back into the lakes.
What happens to all the dead carp?
“They’ll get caught up in trees along the river and just
decompose,” Beyler said. “A lot will end up downstream and float
into the Rock River. We’ve been working with the biologist for the
Rock River in Jefferson County, and although in some cases we try
to remove the dead fish, in this case we determined that it would