DULUTH – The virus that causes COVID-19 has been detected in Lake Superior at popular Duluth beaches — though it's unlikely it can spread via the water.

Traces of SARS-CoV-2 were found in the water on Park Point, below Leif Erikson Park, at the E. 42nd Avenue beach and at Brighton Beach over the Sept. 11 and Sept. 18 weekends. The source of the virus is unknown.

"The research team describes the detection level at 100 to 1,000 copies per liter, or 10,000 times lower than levels observed in wastewater," according to the University of Minnesota Medical School, Duluth Campus. "The CDC is not aware of any scientific reports that indicate the virus can spread to people through exposure to lake water."

Researchers have been testing water samples every weekend since July at eight Duluth beaches. The goal is to further scientific understanding of how the virus acts in the water and whether it can spread there.

"Water has not been shown to be a significant source of infection. ... Water is not a natural environment for the virus," lead researcher Richard Melvin said in August. "However, we want to provide clear, scientifically sound information that citizens, public officials and business owners can use to make informed decisions about water-related activities."

It's more likely the virus will spread through the air among people packed too tightly on beaches, experts say.

Water testing will continue with additional funding through the Minnesota Sea Grant, which provided $10,000 to initiate the project.

Researchers will work with lake current experts and the Minnesota Department of Health to investigate the source of the virus found in Lake Superior.

Brooks Johnson • 218-491-6496