Oxygen Levels In Minnesota Lakes Dropping Faster Than Oceans, Study Finds
MINNEAPOLIS (WCCO) -- Climate change is causing earth's temperature to rise, and as that happens, the level of oxygen in our lakes is going down.
That's according to a study released Wednesday, co-authored by University of Minnesota researchers. They found dissolved oxygen levels in lakes around the world are declining at a faster rate than oceans. Eighty-four Minnesota lakes were included in the data set.
Brian Nerbonne, a regional fisheries manager with the Minnesota Department of Natural Resources, says the agency regularly measures dissolved oxygen levels in lakes.
"Climate change is certainly affecting all the lakes in Minnesota. Some are more sensitive than others," Nerbonne said. "Dissolved oxygen's really important for aquatic life that lives in our lakes. It's something we've been concerned about in the Department of Natural Resources for a number of years."
Nerbonne says the new study confirms those concerns. It spanned about 400 lakes around the world going back to the 1940s. It found that lakes are getting warmer, which lowers oxygen levels. That hurts fish habitats and biodiversity, and increases greenhouse gas emissions.
Gretchen Hansen, a University of Minnesota assistant professor of fisheries ecology and a co-author on the study, says we must act fast.
"There are direct management actions we can do to slow down or reverse these trends," Hansen said. "[That's] kind of the hopeful point of it."
Nerbonne and Hansen say local efforts should be focused on stopping unwanted nutrients from getting into the lakes, because those cause damaging algae blooms. That means controlling how surrounding land is used.
"Minnesota is actually really a leader in devoting resources and money to protecting watersheds to slow down and reverse these oxygen losses," Hansen said.
Hansen and other U of M researchers are now turning their sights specifically to Minnesota lakes in order to refine their recommendations on how habitats can be better protected here.