Superior in good shape, but not in clear
HOUGHTON — Conditions are largely good in Lake Superior, said Rob Hyde. But steps will have to be taken to keep it that way.
Hyde, a Great Lakes program officer for Environmental and Climate Change Canada, Canada’s environment department, spoke Tuesday at one of two public events as part of the State of Lake Superior Conference. The three-day conference is hosted by the International Association for Great Lakes Research.
The department is one of more than 30 federal, state, provincial and tribal government organizations that collaborate to restore and protect the lake through the Lake Superior Partnership Working Group. Those agencies are working with another 170 communities, businesses, nongovernmental entities and academics around the lake, including at Michigan Technological University, Hyde said.
“We’re looking to make sure we understand and maintain our understanding of the condition of the lake, talk about what’s really stressing the lake, and we work together to always try to identify what additional actions are necessary to restore and protect the lake,” he said.
That means listening to other members as well as outside groups with knowledge around the lake, he said.
The Great Lakes Water Quality Agreement, a compact between the U.S. and Canada, sets objectives for the Great Lakes. People should be able to swim, drink and fish. Pollutants shouldn’t be present in amounts that harm fish and wildlife. Lakes should be free of algae growth and invasive species.
Lake Superior scored a “good” on most indicators, including drinking, swimming, pollutants, habitats and species, algae and miscellaneous. Two were only “fair”: eating and invasive species. Groundwater was left undetermined due to a lack of scientific consensus. (The same indicators for Lake Erie found one good, three fair, one fair to poor and four poors.)
The “fair” for eating reflects fish advisory consumption in some areas. Some invasive species also continue to spread.
Trends can be reversed, Hyde said. Lake trout, now plentiful, were nearly wiped out in the 50s by sea lampreys, overfishing and habitat degradation.
Mercury, which is toxic, can reach humans through contaminated fish. After government clampdowns in the 1990s, emissions, from sources such as mining and fuel combustion, decreased by 82 percent from 1990 to 2015.
Remaining major sources nearby are taconite mining in Minnesota and two coal-fired power plants in the U.S. The largest mercury source is atmospheric, largely coal-fired plants from the U.S. and globally.
“The trend of mercury in the atmosphere is also decreasing, so that is other good news,” he said.
Stressors in the lake include invasive species, climate change, chemicals, and fragmented habitats.
The partnership’s management plan has commitments to enhance lamprey control efforts and to eliminate the phragmites plant, a dense wetlands plant that crowds out native species. It’s already harmed beaches and biodiversity in the lower Great Lakes, Hyde said.
Climate change could increase the temperature water temperature by as much as 12 degrees by the end of the century, Hyde said. (After the panel, attendees overwhelmingly selected climate change as the greatest issue facing the lake.) Cold-water fish, such as brook trout, would be stressed. More extreme rain events are also likely, as are more algae blooms.