North Shore watershed clean for now, but facing risks
Jun 15, 2017 09:09AM
The Lake Superior-North watershed covers more than a million acres in the state's Arrowhead region from the Baptism River, seen here, to the Canadian border. Nate Jorgensen file
A watershed along Lake Superior's North Shore is one of the cleanest in the state, but it faces threats to its water quality, a new report says.
The Lake Superior-North watershed covers more than a million acres in the state's Arrowhead region from the Baptism River to the Canadian border. It includes some of Minnesota's most scenic rivers that plunge over steep waterfalls into Lake Superior.
The watershed contains some of the least-polluted water bodies in the state, according to the Minnesota Pollution Control Agency report.
"They maintain really low levels of pollutants like nutrients and sediment," said John Sandberg, a research scientist with the MPCA. "They have excellent habitat for aquatic organisms like many different types of cold-water fish brook trout, sculpin, different types of minnows. And we found quite a few rare and really sensitive macroinvertebrates — aquatic insects — that live in these streams and rivers."
The good water quality likely can be traced to the fact that the region is dominated by natural forests and wetlands and relatively low levels of development, Sandberg said. Grand Marais, population 1,341, is the largest city in the watershed.
However, Sandberg said some of the watershed's lakes have shown a decline in water clarity. He said they tend to be the more heavily developed lakes in the watershed.
"Now they're not heavily developed like a Lake Minnetonka or some really heavily developed lakes across the state," he said. "But those are the more developed lakes in that Arrowhead region, and that's where we tend to see some of these declines in transparency."
The report says climate change also poses a threat to the watershed, since many of its streams support fish and other organisms that depend on cold water.
The MPCA's next step is to develop strategies for protecting the watershed, Sandberg said