Scientists try to get a handle on invasive carp at St. Paul's Como Lake

It's proof that anyone can have a bad day on the lake.

A team of scientists — outfitted with underwater fish-tracking technology that would make the average angler drool — was shut out during the first-ever attempt to harvest invasive carp from St. Paul's Como Lake on Friday.

Scientists had been tracking 30 microchipped carp living in the lake, in addition to monitoring water temperatures and other conditions. But when they triggered four large box nets — baited with corn and submerged near the shoreline — on Friday morning, all four came up with zero carp and just a smattering of small panfish.

"This is part of a process to figure out how to catch these fish," said Przemek Bajer whose company, Carp Solutions, was contracted by the Capitol Region Watershed District for carp removal. "We do this every day, so we are not too fazed. It's all part of the game."

In other words, it's not over. Scientists will return twice this fall with plans to net some of the carp. The bottom-feeding fish stir the lake bottom looking for food, which releases nutrients that in turn feed algae, lowering water clarity and causing a host of other problems.

"We know they're in there. We are using the best available science to understand their behavior and get them into the nets," said Britta Belden, water resource project manager with the watershed district.

Warmer temperatures lower oxygen levels in the water, which affects carp behavior, said Bajer, a University of Minnesota assistant research professor who is part of the U's Minnesota Aquatic Invasive Species Research Center. The research doesn't show an abundance of carp in Como Lake, he said — it took his team three days to catch the 30 they tagged earlier this year.

The team had been baiting nets for several weeks late this summer, but wasn't seeing a lot of action on their tracking. Then, things picked up earlier this week.

"Three nights ago, there were nine [tagged fish] in one of the nets," Bajer said.

But then activity dropped to nothing in the last 24 hours, and they wanted to see what was going on. Though Friday's attempt was unsuccessful, the changing season will increase the odds of netting some fish, Bajer said.

"We tend to do better in the fall when the water cools off and there is more oxygen in the water in lakes with poor water quality and algae blooms," he said.

Invasive carp removal is the latest in a series of efforts by the Watershed District and others to clean up Como Lake. The Watershed District — which was formed in 1998 at the behest of a group of residents concerned about Como Lake — has a long-range plan that includes chemical treatments, stormwater management, planting native plants around the shoreline, reintroducing native aquatic plants to the lake and managing invasive plant and animal species.

Belden said community support for efforts to improve the lake has been overwhelming.

"The community is incredibly invested in this lake," she said. "They are very passionate about it and want to see it do well."

Sheila Johnstone, who walks around Como Lake daily with her roommate, Horace Dyson, was one of the bystanders watching the nets being checked Friday. She wholeheartedly supports efforts to improve the lake — and can now enjoy sitting by the water.

"It smells and looks a lot better," she said.