WORTHINGTON — More than mid-way through this winter, it’s beginning to appear less likely that a wintertime seining of carp in Lake Okabena will happen this season.
Ice thickness on the lake didn’t reach depths to support vehicle traffic until mid-January, and when the deep freeze worked its magic, in blew a blizzard to create deep snow drifts across the Worthington lake.
The snow created challenges in getting around to find the carp, Okabena-Ocheda Watershed District Administrator Dan Livdahl said.
Last week, he walked two paths across Lake Okabena with his radio telemetry equipment in hopes of picking up the signal of the 15 carp surgically fitted with radio-tagging devices last May. What he found is a lack of carp schooling together. Over the course of two days, he captured signals from nine of the 15 carp — Ogre, Oke, OKGo, OK60, Oops, Olga, Oma, Ole and Ovie.
“We have two fish that have been missing since last summer and I think they’re dead,” Livdahl said of Otto and Oscar. He picked up their signal on the radar last May, within a couple of weeks of being surgically implanted with the tracking devices.
“They said they could lose 10% to 20% to mortality from surgery,” Livdahl said of the biologists from Wenck Associates who performed the surgical implants. He believes the carp were possibly discovered deceased on the shoreline prior to last June’s Regatta and thrown in the garbage. Then again, it’s possible the carp were taken out by bow hunters who didn’t notice the tags.
Another possibility, however, is that the fish made it over the dam and are now somewhere in Lake Ocheda. With that lake’s three basins, it’s too big of an area for Livdahl to look for the missing carp.
As for the nine carp found last week, three were in Sunset Bay, fairly close to the causeway. The other six were spread out — a couple near Chautauqua Park, one near Sunset Park and the rest at different points along the southern side of the lake.
Since the carp haven’t schooled together, Livdahl said it would be a waste of money to try to do any seining at this point.
Southwest Minnesota’s commercial fisherman, Scott DesLaurier, told Livdahl the carp aren’t schooling this winter because of high oxygen levels in the lakes. The high oxygen levels keep the carp more alert, and when they realize there is netting activity taking place, they escape the area, DesLaurier said.
He still plans to survey Lake Okabena with his sonar equipment the week of Feb. 16.
With the carp spread out in the lake, Livdahl is in conversations with Wenck about the carp control program moving forward.
The whole point in reducing carp in Lake Okabena is to improve water quality. The lake is impaired, and high populations of the rough fish stir up sediment and can destroy the vegetation needed in a healthy lake.
In addition to the 15 carp inserted with radio tags last May, Wenck personnel placed Passive Integrated Transponder (PIT) tags in 173 carp last October. The less invasive tagging program was done to help determine a better estimate of carp numbers using a formula that would be implemented during carp seining.
Currently, Livdahl said discussions are underway to keep the carp in Sunset Bay during spawning. Last year, 11 of the 15 radio-tagged carp were found in the bay during June spawning.
“We would like to put some sort of barrier between Sunset Bay and the lake, but we don’t want to (mess with) people fishing,” Livdahl said, noting lures could get caught in the barrier and create problems at the channels between the lake and the bay. There’s also concern the barriers could get clogged with debris.
An electro-fishing barrier also creates concerns, particularly with people who like to fish at the channels.
As for seining in Sunset Bay during open water seasons, the primary obstacle is the lack of a boat landing.
“This is a work in progress,” Livdahl said of the project to reduce carp in Lake Okabena. “My direction to Wenck was to give us some options so we can move forward.”