Lake seining success yet to be seen

• Fish

Brian Korthals/Daily Globe Buckets of fish await transfer to the live wells of a transport truck during buffalo harvest from Lake Bella in October.

Talk about it

WORTHINGTON — After pulling his nearly half-mile-long nets through Lake Bella over a five-week period this fall, commercial fisherman Scott Des Lauriers hauled in an estimated 170,000 pounds — 85 tons — of rough fish.

But will the removal create a positive impact on water quality in the shallow prairie lake?

That is yet to be seen, according to Okabena-Ocheda Watershed District Administrator Dan Livdahl. It may take a year or two to see the impact the fish seining had on Lake Bella, but Livdahl said earlier this week he isn’t really optimistic.

“Seining alone will not improve lake water quality,” he said. “It could be one tool in the toolbox to manage the fish in the lake.”

Those other tools, Livdahl said, could include a lake draw-down, which would result in a die-off of both rough fish and game fish; followed by adding a lot of predator fish to the lake to feed on carp eggs and help control rough fish reproduction.

The fish seining project was discussed this summer during a meeting of the Lake Ocheda Landowners group, and Des Laurier — whose commercial fishing license keeps him busy in southwest Minnesota — promised to bring his nets into both Lake Bella and Lake Ocheda.

Two weeks ago, Des Laurier was making arrangements to move to Lake Ocheda, but high winds and an equipment breakdown kept him at bay. Now, with a thin sheet of ice covering the lake, he’s had to call it quits for the season.

Des Laurier said Lake Ocheda is at the top of his list for seining as soon as the water reaches an optimal temperature next fall. Seining when the water is too warm causes problems for the game fish, he said.

Buoyed by

buffalo at Bella

Des Laurier’s uncle used to be a commercial fisherman in southwest Minnesota, and Lake Bella was never great in terms of harvesting large amounts of rough fish. That certainly wasn’t the case this time, however.

“We had really only expected to make a couple of hauls there, but our first haul was a big haul and we kept catching fish,” Des Laurier said.

He estimates 90 percent or more of the rough fish removed from Lake Bella this fall were buffalo — a fish similar in appearance to carp that feeds primarily on microorganisms and algae in a lake.

By comparison, carp are bottom dwellers and tend to cause a lot of damage in lakes because they stir up the sediment. When sediment is stirred up, sunlight isn’t able to penetrate the water to fuel growth of beneficial plants needed to stabilize lake bottoms.

Livdahl said it is possible that less fish in the lake next year could create less stirring of the sediment. At the same time, though, a reduction of buffalo means fewer fish will be eating the algae.

“Even if we see an improvement in water clarity, we may not be able to attribute it to a reduction of fish,” Livdahl said. He’s already planning to take water clarity measurements with a Secchi disk on Lake Bella next summer to see if the seining has made a difference.

“In a 110-acre lake, (the seining) removed a lot of biomass,” he said. “You’d expect there to be some difference in water quality.”

Still, Livdahl said, each year is different. Major rain events can cause water to flow quickly through the system, carrying nutrients and sediment with it from the top of the watershed north of Lake Okabena, through Lake Ocheda and into Lake Bella, which is at the bottom of the Okabena-Ocheda Watershed.

“Removing the fish can’t hurt things,” Livdahl said. “It might help in the short-term.”

Both Livdahl and Des Laurier admit there are likely more rough fish in Lake Bella than previously thought.

Catching carp … or not

According to test maps created by the Minnesota Department of Natural Resources, Lake Bella is believed to have a high population of carp. Des Laurier, however, said they weren’t being caught.

“Carp are much more difficult to catch because they hug the bottom of the lake,” he explained. “Buffalo are more of a mid-water fish — they’re not looking for a place to get out of the nets.”

Des Laurier completed two hauls on the south end of Lake Bella, and another four hauls from the north end, which was more heavily populated with fish.

“We had one on the north end where a bunch of fish got away from us — there were so many in the net they went over the cork line,” he said.

The success left Des Laurier with a plan to return to Bella after he’d completed some hauls from Lake Ocheda, but the fall-like weather didn’t hold out long enough.

“Anytime in the fall before freeze-up, wind is a major factor,” he said. “The ice is a huge hindrance. Our net is a half-mile long, and if we collected all the skim ice in that haul, you’d never move it.”

Market for rough fish

With the hauls he completed on Lake Bella this fall, Des Laurier made five semi-trailer tank shipments of live buffalo fish to New York. The carp and other rough fish — one catfish and one sheephead — were sent to Spirit Lake, Iowa, where they are processed and then shipped to New York to be marketed as whitefish.

All of the game fish caught in the nets were safely returned to the water during the fish harvest and not affected by the seining process.

Des Laurier said removal of the rough fish has created more room for the game fish to thrive, but he really didn’t see great numbers of game fish in Lake Bella.

“We caught about 20 nice-sized northerns, but they could have been the same fish getting caught in the nets twice,” he said. “We caught about the same number of walleyes.”

The nets also caught “a few crappies and one or two bullheads,” although most of the smaller fish are able to get through the five-inch spaces in the mesh netting.

With Des Laurier’s shipments of buffalo to New York, along with those of other commercial fishermen across the country, the market for buffalo has dipped. Until it rebounds, he put the rest of the rough fish from his Lake Bella hauls in a holding pond in Fulda. He has equipment in place there to be able to pull the fish through the ice later this winter.

Meanwhile, after Jan. 1, he and his crew will start seining again — working on East Graham and West Graham in northern Nobles County, then crossing into Murray County to work at Talcott. If time allows, he also hopes to get to Round Lake and Little Spirit Lake.

“I think Lake Ocheda is just way too shallow to mess with in the winter,” Des Laurier said.

Outlook for Ocheda

With such low water levels now on Lake Ocheda, Livdahl said there could be a freeze-out this winter, causing a significant fish kill. The water level at the Lake Ocheda dam is about 1.5 feet below normal, which is significant considering the lake depth is usually only 3- to 4 feet deep.

If a fish kill does occur, Des Laurier said, it would have far more impact than he could ever hope to have by seining the lake.

The problem is that if any carp do survive a freeze-off, their reproductive efforts would quickly repopulate the lake. That’s why Livdahl and the Okabena-Ocheda Watershed District board are looking for more tools to use from the toolbox.

For the last two years, the OOWD has tested a model fish barrier designed and constructed by Marv Rall of Worthington. The barrier was placed on one of the 10 bays on the Lake Ocheda dam, and Livdahl has been monitoring its effectiveness.

“We just wanted to see if it filled up with trash — if the water continued to flow through it,” he said. It was also put to the test during this summer’s high water levels to make sure it wouldn’t break.

The purpose of the fish barrier is to keep carp from swimming from Peterson Slough and Lake Bella into Lake Ocheda.

“We want to keep as many reproductive-age carp out of the lake as possible,” Livdahl explained. In the times that he’s visited the dam, he’s seen the fish barrier work to keep carp from swimming through, but since it was only placed on one bay, the fish eventually gave up their fight with the barrier and simply swam over to one of the nine open bays.

Livdahl said the barrier was designed to allow a northern pike to get through, but not a one-year-old carp.

Ultimately, the regional hydrologist will have to approve of the design and plan for the fish barrier, and that’s the OOWD’s next step in the process. Livdahl said he plans to submit the design soon.

“The final step would be convincing people that it’s worth the sacrifice,” Livdahl said.

Those people he needs to convince are the Lake Ocheda landowners — those who live or farm around the prairie lake.

Tags: news, lake, seining