Global warming could spur algae growth, oxygen loss in Lake Superior

By Emma Ogutu
ogutu@msu.edu
Great Lakes Echo
Oct. 7, 2009

Editors note: This is part of a series relevant to the International Joint commission’s biennial meeting in Windsor today and Thursday.

One of the reports a U.S. and Canadian advisory commission will consider today in Windsor will look at runaway plant growth in the Great Lakes.

Members of the International Joint Commission, which advises the governments on environmental issues, will likely hear that there is no cause for alarm about excessive growth of algae in Lake Superior.

But global warming is catching up with the Great Lakes, Superior included, and it may soon undergo changes that could turn it into the perfect host for algal blooms.

The effects of global warming could actually be more complicated than just that.  An important question is how prepared the commission and other government agencies are to handle emerging global environmental issues.

“Global warming is here,” said Melvin Visser, a former co-chair of the Great Lakes Regional Corporate Environmental Council and the author of Cold, Clear and Deadly, a book about pollution of Lake Superior and other northern Lakes.
With the earth heating up, the quality of water in Lake Superior will start declining, he said

Others agree.

“Increased water temperatures will definitely hike the bacterial action in any lake,” said Les Kaufmann, a marine biologist at Boston University.  “Bacteria decay matter, producing  nutrients which increase the food supply for algae and in a process called eutrophication eventually deprive the water of oxygen.”

When the lake is not receiving enough nutrients from decomposed matter, there is nothing to stimulate the growth of algae, Visser said. But as the lake warms, the bacteria become more active. That provides the lake with more nutrients which enhance the growth of algae.

It’s not clear what will happen. Orlando Sarnelle, a limnologist and ecologist at Michigan State University, said that there are insufficient nutrients getting into Lake Superior to produce eutrophication, given the sparse human and industrial activities around it.

Yet Visser believes that there are a lot of nutrients and energy locked up in the food web within the vast lake.

“The fact that Superior has been clear this long may be deceptive,” he said.

A Minnesota Sea Grant study found that the extremely low temperatures in Superior delayed decay by making bacteria less active. According to Visser, it is this, almost non-existent decaying process that makes the lake appear to be very clear.

Eutrophication reduces the concentration of oxygen in lakes, causing aquatic life to die.

“Global warming is certainly a major challenge and both the U.S. and Canada need to take action at appropriate levels,” said Frank Bevacqua, the commission’s public information officer.

However, he said that global environmental concerns affecting the Great Lakes are not prominent on the agenda this week, even though the global concern had potential for a ‘very significant effect’ on the lakes.

“IJC is really not the major player here, we have a small role in legislative matters,” he said.

But some Great Lakes activists urge a more active role for the commission.

Jim Ludwig, former president of the Michigan Audubon Society and an independent Great Lakes researcher, believes that the commission is not doing enough.

“IJC could have a great influence on environmental legislation but so far it hasn’t shown enough stomach for fighting for its proposals,” Ludwig said.

Part of the problem, Ludwig said, is that both governments have too many agencies and departments managing the Great Lakes.  As a result, he, said, “There is just a bunch of people pointing fingers at each other and not implementing much.”

Ludwig believes that the commission should be willing to critique all these agencies.

“If you are going to be a watchdog, you should be willing to offend and criticize people,” he said.