Project aims to control invasive carp west of Lake Minnetonka
Star Tribune, 6/23/2018
A kayak glides across still water. Families stroll a boardwalk, passing anglers on a pier jutting above Wassermann Lake. Picnic areas and parks coexist with wildlife along the lake’s western shore.
Anna Brown, a planner and project manager with the Minnehaha Creek Watershed District, can only imagine these scenes. For now, the water is cloudy and algae crowds the shore.
And Wassermann Lake, like others in its 14-lake system southwest of Victoria, is filled with the common carp, the fish driving the disruption of these waters.
But there’s a plan to fix that and realize visions like the Wassermann West Waterfront Park that Brown dreamed of. “We effectively need to get [the carp] out and create a cleaner slate,” she said.
In May, the watershed district received a state grant of $567,000 for a three-year plan to remove carp, an invasive species that stirs up lake beds, uproots plants and encourages algae growth.
The project, which begins this summer, is part of the Six Mile Creek-Halsted Bay Habitat Restoration, a 10-year, multiorganization effort to make 2,488 acres of the subwatershed more hospitable for wildlife and people as development in the area grows.
The organizations involved include Carver and Hennepin counties, the Three Rivers Park District, Laketown Township and the cities of Minnetrista, St. Bonifacius, Victoria and Waconia.
Introduced as game fish in the 1880s by European settlers, carp long have made Minnesota’s waters their home. In recent years, as the watershed district focused on creating a plan to restore the subwatershed connected by Six Mile Creek, it enlisted University of Minnesota researchers to see how deep its carp problem went.
From 2014 to 2016, the Minnesota Aquatic Invasive Species Research Center found levels ranging from unsurprising to shocking. The worst area was Halsted Bay, one of Lake Minnetonka’s most degraded bays, where levels were “off the charts.”
“We were catching more than one carp a minute,” said Justine Dauphinais, the project’s research fellow. “And that was the highest catch rate we’d seen in any of our research, since 2008 when we started this.”
On average, carp populations were about five times the target for sustainability. Using researchers’ findings, the watershed district created a plan to remove the carp, limit their growth and promote predator populations.
That connection to research made the plan stand out among 52 applicants for the grant money, said Julie Blackburn, a member of the Lessard-Sams Outdoor Heritage Council.
“It was so connected,” Blackburn said. “Clear to the science, clear to see they had identified the pathway to restoration.”
Blackburn said the plan also stood out because its implications were so far-reaching — people, fish, birds, plants and other water bodies all stand to benefit. It helped that the project is in the metro area and abuts Lake Minnetonka.
By combining the efforts of researchers, citizens, watershed districts and state government stakeholders, Brown said they can attack things systemically, targeting carp populations before moving on to the balanced ecosystems and vibrant recreation areas of their visions.
“I think often people think of impaired water bodies as something that’s past the point of no return or something along those lines, and in this case there’s a healthy fish and healthy plant community just within arm’s reach,” Brown said. “It’s just about taking the right management steps to bring that out.”