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Outdoors: Concerns rise over Lake Superior's low water levels

Tim Eisele
Special to The Capital Times  —  8/22/2007 10:45 am

Lake Superior's fishery is in pretty good shape right now, but there are major concerns about water levels.

Steve Schram, supervisor of the Lake Superior fishery for the Department of Natural Resources in Bayfield, said lake trout populations in the lake are recovering nicely and the whitefish fishery has commercial catches that are near an all-time high.

"We are seeing a big change in the communities. This used to be a lake dominating by herring, as forage fish 100 years ago, but then they declined after over-harvest in the 1940s and smelt were introduced and they increased," Schram said. "But, now that has reversed and smelt have declined while native herring have increased, which is a good thing."

Coho salmon populations are fairly stable, according to Schram, and the Chinook salmon harvest is low probably because forage fish are under intense pressure from predators.

Walleye populations are going through a change and used to be stocked, but stocking stopped six years ago and the population is changing to larger, older fish. Biologists are not seeing much natural reproduction from walleyes and had planned to begin stocking again this year but that was curtailed when VHS concerns entered the scene.

"Smallmouth bass are doing well, with a number of year classes, and the minimum size limit has allowed fish to reach good size," Schram said. "We did a bio-energy study to see if there was enough forage to feed all the big predators, and there is."

Schram said that Lake Superior water levels are down 18 inches from normal and the north has been in a prolonged drought, and less ice cover has sped up evaporation.

"The lake has gone through cycles in the past and we hope it will come back up," he said.

Roger Gauthier, program manager with the Great Lakes Commission in Ann Arbor, Mich., has been involved with Great Lakes hydrology issues on behalf of the Commission and earlier the U.S. Army Corps of Engineers for about 30 years. He said there was a distinct drop of almost two feet in Lake Superior's water levels between last August and this past March.

"That's a precipitous drop, and Lake Superior's water levels have been running close to a record low (1925 and 1926) since last September," Gauthier said. "Lake Superior has over 50 percent of all the total storage of the Great Lakes, which is quite substantial. It is clearly related to evaporation during that time."

Gauthier said that the ice cover is never 100 percent complete on Lake Superior, but recent ice cover was not as thick or as long as usual. In addition, snowfall was significantly below average, and he points to those as the factors for lower water levels now.

Gauthier does not believe there is any proof that water is being diverted from the lake, but instead the levels are occurring purely from climatic reasons.

"The Great Lakes are the canary in the coal mine, and if we set new record lows at the same time as doubling of atmospheric carbon dioxide, a lot of people will point to climate warming," Gauthier said. "Considering their size and where they are in latitude, the Great Lakes are a good indicator of what is happening in global dynamics."

Another organization, the Georgian Bay Association, which represents people living on Lake Huron Bay, has reported that drought and evaporation have contributed to steep drop-offs in lake water levels, but that dredging and other human activities on the St. Clair River is responsible for Lakes Michigan and Huron losing 2.5 billion gallons of water per day.

Tim Eisele
Special to The Capital Times  —  8/22/2007 10:45 am