Each Saturday morning, by kayak or on foot, with volunteers or on his own, Sean Connaughty picks up trash in Lake Hiawatha. Some 6,500 pounds of it from the south Minneapolis lake over the last five years. Pop bottles and plastic barrettes. Styrofoam and syringes.

Connaughty, 53, sorts it, bags it and records its origins. Then, sometimes, he uses it to make art.

In the sculpture garden outside the Minneapolis College of Art and Design stand four billboards that, at first, look like advertisements. But Connaughty is drawing a different kind of attention to mega corporations he’s found to be the biggest sources of trash in the lake, recreating their logos with litter.

The iconic curves of McDonald’s golden arches are, for example, bundles of straws.

“If we are going to change this situation — not just for Hiawatha but the larger situation — everyone has to own their part, their responsibility,” he said. “That includes the corporations.”

With these new works, Connaughty, an artist and University of Minnesota professor, is drawing on his personal activism on behalf of Hiawatha, the 55-acre lake a few blocks south of his house.

In his neighborhood and at City Hall, Connaughty has become known as the lake’s outspoken caretaker, dedicated to the daily work of dealing with what officials have acknowledged is a problem with trash. His art broadens that preoccupation, turning a local challenge into a global statement about humans’ effect on the environment.

“It’s been long-seeded,” said Kerry Morgan, MCAD’s gallery director and program director of the McKnight Foundation’s fellowships for midcareer visual artists. With Lake Hiawatha, “he’s found a way to integrate what is a passion of his with a skill set that’s uniquely his.”

Artists are increasingly grappling with concerns about the environment, from climate change to water degradation, mixing art with their personal activism. Museums and galleries are responding, hosting exhibitions that consider those new works and also look back at how artists have depicted ecology for centuries.

A 1989 graduate of MCAD, Connaughty had applied for the McKnight Artist Fellowships and their $25,000 prize for more than 20 years, he said. In 2018, he got it. In addition to the sculpture garden, Connaughty’s trash-based work also appeared in MCAD’s indoor gallery. This spring, he’ll be a part of a discussion at the Minneapolis Institute of Art, Morgan said.

Connaughty has been creating eco-focused artwork for decades. He traces his concern to his childhood in Eden Prairie, where he grew up on a dead-end dirt road “surrounded by prairie and forest and beauty.” Then that land was leveled, developed. “It stuck with me,” he said.

In recent years, he created a series of underwater biospheres that grew in size and complexity, culminating in an orb-shaped ark, 7 feet in diameter, that floated — briefly — in Lake Superior. The “Ark of the Anthropocene,” a concrete sphere holding plants in its belly, bobbed in the harbor for 38 hours in 2014, then sunk.

Connaughty decided that he wanted to launch the ark in Lake Hiawatha. In researching his proposal, he spent many hours in and around the lake, discovering its troubles. To figure out how so much trash was getting into the lake, Connaughty created an experiment:

He dropped a small green ball into a storm drain next to his house. Two weeks later, he fished the ball out of the lake, near a storm sewer outfall. He began advocating for a mitigation system that would screen out trash and treat pollutants. Connaughty is on an advisory committee that’s working on recommendations for the Hiawatha Golf Course property, including stormwater diversion and trash management.

“When I was a kid, I had no agency to effect any change,” he said. “I was powerless. As an adult, maybe I can do something about it.”

In August, Connaughty met with Minneapolis Mayor Jacob Frey, presenting to him the results of this year’s Earth Day cleanup. He and his Friends of Hiawatha volunteers picked up 18,961 pieces of trash, including some 3,550 pieces of Styrofoam. Bottle caps and spray cans. They pulled some 1,200 blue bristles from street-sweeping machines.

“I didn’t recognize them as trash, as litter,” Morgan said of the blue plastic strips. But after participating in cleanups, she started seeing them everywhere. “That’s the beauty of what Sean’s doing,” Morgan continued. Now, she picks up litter on a daily basis.

The billboards, too, began with a big pile of trash — more than 300 pounds of it, sitting in MCAD’s gallery. Students, faculty members and neighbors were invited to help separate it. Connaughty traced back the trash to the corporations responsible for creating it: McDonald’s, Mars, PepsiCo and CocaCola. Those companies have responded to his project, emphasizing their goals to make their packaging recyclable or compostable.

A Mars spokeswoman said, in part, that the company was “disappointed to learn” that its packaging has been found in the Lake Hiawatha Trash Survey and that it remained focused on a goal to design packaging that is 100% recyclable, reusable or compostable by 2025. A McDonald’s spokesman noted that McDonald’s restaurants in Minneapolis comply with the Green to Go Environmentally Acceptable Packaging Ordinance, which includes recycling and garbage receptacles.

On his walks along Lake Hiawatha wearing a wide straw hat, Connaughty has chatted with neighbors who know his mission. Mostly, their response is positive, he noted. But he also noticed that when he mentioned the 920-acre stormwater system that extends to Lake Street, “people want to blame somebody.

“Some people went as far as blaming immigrants,” Connaughty said. “Given our times, I didn’t want to contribute to a toxic narrative.”

So he took a deep look at who’s responsible, arriving at the idea that it’s a triad: the consumer, the producer and the municipalities.

“It would be easy to get misanthropic,” he said matter-of-factly. “The goal just seems to be getting further and further away.”

But he’s an optimist at heart, he said. If people change their behavior, companies change their practices and the city puts a system into place, he said, maybe, just maybe, “the lake will be swimmable again.”