Lake Erie "Dead Zone" Getting Worse: Scientists Confused

Windsor Star
07/09/2002

University of Windsor biologist Jan Ciborowski is leading the Canadian side of an international effort to learn the causes of a "dead zone" threatening a large portion of one of the Great Lakes.

"It's been a bit of a shock ... things are getting worse," Ciborowski said of a summer phenomenon that is seeing the emergence of an oxygen-deprived area devoid of life in the deepest parts of Lake Erie. It's a repeat of a problem that plagued the lake during its most polluted era in the 1960s and '70s, but one that scientists thought had been licked.

The problem has not only resurfaced after a multi-year and multibillion-dollar binational effort at removing the suspected causes, primarily phosphorous overloading, but the dead zone is forming earlier in the year.

The U.S. Environmental Protection Agency is funding a $500,000 US effort that will see 40 researchers from 17 universities, armed with an eight-boat flotilla of research vessels, scour the lake in search of answers to why the lake bottom is dying.

Almost half that money is going to five Canadian research groups led by Ciborowski, who is joined in the effort by Great Lakes Institute for Environmental Research scientific colleagues Tim Johnson, who is based at the Ministry of Natural Resources research station in Wheatley and Doug Haffner, the Canada research chair for Great Lakes environmental health.

Possible causes

Ciborowski said a handful of potential villains has already been identified, including zebra mussels, climate change and increased levels of ultraviolet radiation getting through the Earth's protective ozone layer.

As the shallowest of the Great Lakes warms in the spring stratification occurs, with the oxygen supply near the bottom getting cut off by warmer layers of water nearer the surface. If the oxygen levels there reach zero before cooler temperatures arrive in the fall, an anoxic situation develops creating a barren region.

A dead zone is feared for Lake Erie's central basin by the end of the summer. How it might have an impact on the area's important commercial fishery is "very much" a concern, he said.

Ciborowski co-organized a 1999 Lake Erie conference in Windsor that led to the formation of a scientific network and development of a Lake Erie Millennium Plan, both of which are credited for the quick response to this latest threat to the most biologically diverse of the five Great Lakes.

"We had this proposal ready to go," said Ciborowski, adding it was "alarming new data" by Environment Canada and the U.S. EPA that triggered the release of funds enabling this summer's action.

IN A NUTSHELL

What: Great Lakes researchers looking into the cause of a Lake Erie "dead zone," an area devoid of life.