WORTHINGTON – Okabena-Ocheda Water District Administrator Dan Livdahl spoke to the Worthington City Council during a special meeting this week, updating them on attempts to control the carp population in Lake Okabena.
Livdahl told the council that the University of Minnesota has been pioneering techniques for years, trying to find a weakness in the carp life cycle. To date, seining for the carp as the only action has never been successful, Livdahl said, because the fish reproduce too quickly.
In 2019 and 2020, carp were captured and tagged with transponders that would allow the district to track their movements, hoping to find a way to interrupt the spawning cycle of the fish. According to Livdahl, the spawning seems to be happening in a concentrated area of Sunset Bay, with a basically a two-day window.
Options to interrupt the spawn would be to either trap them in the bay and let them get killed off in winter, or exclude them from the bay, which would give natural predator fish a chance to eat many of the eggs released by the carp.
The most effective method would be the winter kill, Livdahl said, but it comes with problems – namely, the smell and mess of all the dead fish in the spring.
“This is something we wouldn’t even attempt unless the city and the people on Sunset Bay agreed to it,” he said.
After considerable discussion, the council decided that an informational meeting on the subject should be planned, so residents of Worthington can hear options and offer their thoughts.
The watershed district has spent over $55,000 on equipment, professional assessments and one seining event. The city had budgeted $52,000 to carp management in 2019, which will be transferred to the OOWD.
“We’ve spent a lot of money to get this far,” Livdahl said. “It would be a real mistake for us to not continue at this point.”