State officials are repairing an electric fish barrier in Lost Island Lake, which is near Ruthven in northwest Iowa. Mike Hawkins, a fisheries biologist with the Iowa Department of Natural Resources, says the barrier is targeting a fish that’s considered a nuisance.
“We’re using that one to prevent common carp, which were introduced into Iowa back in the 1800s and have caused all kind of problems for us in our natural lakes, especially our shallow natural lakes,” Hawkins says.
Lost Island Lake is just 16 feet deep. Hawkins says carp destroy native acquatic plants and increase sediment in the water by rooting around the bottom of a lake. “They just do a lot of things that are not good for the lakes,” Hawkins says, “and so in an effort to reduce their ability to reproduce, which they do in connected marshes, we put an electric barrier there to keep them from migrating.”
Over the past several years the DNR has stocked Lost Island Lake with walleye, northern pike and even large mouth bass. “We actually have several barriers at Lost Island Lake to prevent fish from moving into the watershed wetlands, but in one location we resorted to an electric barrier, which is kind of your last barrier option,” Hawkins says. “They’re expensive and tough to maintain.”
But Hawkins says they’re incredibly effective and use a fairly low amount of electricity to create the electrical field in the water to keep the fish from swimming. Over time, though, the water causes erosion damage on the electrodes. Hawkins and his team began replacing those electrodes yesterday.