How much trash is under water in Mille Lacs? A scuba team looked into it.

There were fishing poles, cinder blocks, liquor bottles and golf balls in the tiny portion of Lake Mille Lacs that a scuba dive team sampled over the past week, but it was far less rubbish than they expected to find, the team's leader said.

The preliminary and brief probe of the lake's subsurface, paid for by a $67,000 grant from Minnesota's Clean Water Fund, didn't dazzle organizers with findings of snowmobiles, docks, sunken boats, fishing shacks or automobiles. Rather, divers were surprised by the light loads of litter they found while exploring a sample of heavily fished holes, flats and reefs.

"It's looking remarkably cleaner than we thought it would," said Colin West, founder and chief executive of nonprofit Clean Up the Lake. "We're not seeing significant signs of a problem.''

The group's divers recovered fishing gear, tires, beer cans and a chrome hubcap from an old Buick. But the debris wasn't in heavy concentrations like West has seen in other lakes, he said.

His company's initial inspection of Mille Lacs was spearheaded by Ann Brucciani Lyon, vice chair of the Mille Lacs Area Community Foundation and a member of Minnesota's Keep It Clean Coalition. The coalition, now with volunteers from more than 50 lakes and soil and water conservation districts, successfully lobbied the Legislature in 2023 to tighten waste and garbage controls specific to ice fishing.

"This is about taking a great lake that's loved by a lot of people and making it better,'' Lyon said. "It's a starting point and I'm not sure what will happen next.''

Regardless of what details are revealed in Clean Up the Lake's upcoming summary report, Lyon said the project has boosted public awareness about the undeniable problem of submerged litter washing up on the shores of the 207-square-mile lake. Students from the Isle School District got involved, helping to sort debris pulled from the lake and the scuba team met with community members at a well-attended open house.

Lyon said one purpose of the mission was to encourage more environmental stewardship.

"This kind of data gathering helps to elevate our awareness of what's in our lakes,'' said Pat Murphy, president of Aitkin County Lakes and Rivers Association. "Water connects us all … this starts conversations.''

Mille Lacs is the 13th lake and the first in the Upper Midwest to be examined by Clean Up the Lake, a small organization that made a name for itself in 2022 by pulling 25,000 pounds of trash from Lake Tahoe. The Nevada alpine lake is slightly smaller than Mille Lacs, but attracts far more people — up to 20 million visits a year. The primary sponsor of the Tahoe cleanup hired an artist to make a public sculpture out of the trash.

West said diving in Mille Lacs is a world apart from working in the azure waters of Tahoe, where visibility ranges from 40 to 60 feet. In Mille Lacs, his divers could only see 3 to 4 feet, he said.

The team focused on heavily trafficked fishing spots, like a 35-foot oval hole in Isle Bay that attracts gobs of ice anglers. "They didn't find one piece of litter there,'' West said.

Other locations searched by divers or with an underwater drone included Big Point and Three-Mile Reef, both off the eastern shore. West said late Tuesday that he wanted to sample fishing areas on the north end of the lake, but might run out of time. Thursday is the last scheduled day for exploration.

He said Mille Lacs might not have heavy concentrations of trash because there's no consistency to the wind and waves like on other lakes. The varied contours of Mille Lacs, including its gravelly humps and expansive mud flats, also could play a role, he said. In Tahoe, for example, garbage was densely packed into shelf-like contours on the lake's predictably windward side.

He said his team's observations underwater at Mille Lacs suggest that light litter is getting swept toward shore. "That makes sense to me,'' he said. The junk recovered by divers tended to be heavy and resistant to getting pushed around, he said.

"On our way here, I thought we could be pulling thousands of pounds of trash out,'' West said. "So, it begs the question of 'why not?'''

West, a certified divemaster and film producer, said he has other theories — such as junk could be buried in muck. Many bottom areas of Mille Lacs are covered in loose silt — so much so that walleye anglers routinely deploy special rigs that keep bottom-bouncing lures from getting obscured by dust-ups. West said one diver submerged his arm up to his armpit without touching anything but silt.

Another theory, West said, is that the majority of anglers who fish on Mille Lacs are just good stewards. He also noted that underwater surveys of Mille Lacs will always be of the needle-in-a-haystack variety because visibility is poor and the lake is vast.

Apart from finding trash, his divers were amazed by the concentrations of invasive zebra mussels. They'd pick up an item from the floor shaped like a discarded bottle or another piece of trash, only to realize it was a rock completely covered in mussels.

"The zebra mussels are to a level we've never seen,'' he said.

But, he said, his "overall take'' about submerged litter in Mille Lacs is that the lake is "substantially cleaner than we thought it would be.''

Chad Anderson of the Minnesota Pollution Control Agency said his agency approved the grant in part because no one had previously assessed Mille Lacs for underwater trash. Providing education and raising public awareness about water quality were two other reasons to underwrite the pilot project, he said.

"This was kind of a first crack ... an assessment,'' Anderson said. "If they find tons of garbage, then let's remove it.''

In Prior Lake and perhaps other locations across the state, scuba diving for trash isn't new.

Steve Reinders is a board member of the Prior Lake Association who coordinates the group's annual Dive the Lake Cleanup. Self-funded with the help of private sponsors and volunteers, the event relies on local divers, boat owners and a local marina one morning every June.

"Last year we pulled up half a boat and we've pulled out a whole bunch of telephone poles,'' Reinders said.

At least one snowmobile has been recovered along with common items such as cell phones, sunglasses, boat covers, tires, rims and boat anchors. "You never get all the junk out of the lake,'' Reinders said. "But it's also a public awareness tool.''

At Mille Lacs, Lyon said she and others will be considering how to focus future cleanup efforts.