Great Lakes stressed out

By Debora Van Brenk London Free Press December 19, 2012 

A comprehensive study analyzing and ranking 34 stressors the Great Lakes are battling against shows Lakes Erie and Ontario are under the greatest stress. It’s no coincidence that’s where the highest concentration of people — and the associated variety of pollutants we produce — lives and works. 

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If the Great Lakes were human, they’d be in serious need of stress counselling and intervention.

A comprehensive study analyzing and ranking 34 stressors the giant freshwater lakes are battling against, and where the biggest issues are, has just been released to policy makers and researchers.

The study maps and quantifies how each part of each lake is faring from a bombardment of everything from heavy metal contamination to mussel invasion and high nitrogen levels.

Lakes Erie and Ontario are under the greatest stress, it shows. That’s also where the highest concentration of people — and the associated variety of pollutants we produce — lives and works.

“We’ve all heard the phrase, ‘loving a place to death,’ ” said David Allan, of the School of Natural Resources and Environment at the University of Michigan. “We love these freshwater lakes so much — having made them a foundation of where we live, work and play — that we’re doing them damage.”

Some aquatic ecosystems are feeling the heat from climate change while others are particularly hard-hit by industrial waste or agricultural run-off. “We don’t know enough about the resilience of these locations,” Allan said.

“Is that system reaching the point where it can’t bounce back?”

The Great Lakes Environmental Assessment and Mapping (GLEAM) project took three years and involved the efforts of scores of people in Canada and the U.S, under the leadership of Allan, who spent his boyhood in London and attended Tecumseh public school.

It’s the first comprehensive look at a variety of factors that influence the health of the lakes, and in enough detail to assess their impact on a grid.

The assessments are also weighted so that light pollution, for example, is accorded different ranking of importance than invasive zebra mussels.

That makes it a valuable tool policy makers and communities could use when figuring out where best to spend money and effort, Allan said.

It reinforces that the $1 billion spent in the U.S. on a Great Lakes Restoration Initiative is being spent on places that need it and it also highlights other areas that are in need of urgent attention.

The data could lead to new strategies — perhaps working on areas where a little money could go a long way rather spending a lot of money making only a minor difference.

One hope is that it leads to more informed blueprints for “cost-effective restoration, getting the best bang for the buck, doing it well,” Allan said.

On the map, Lake Ontario is a virtual sea of red — multiple stress factors having a high impact in many places — while Lake Erie appears to be only marginally better. On the Canadian side of Lake Huron, areas of concern include Goderich and areas north of Kincardine.

The research doesn’t suggest the red places are dying or beyond repair, Allan emphasized, only that they are at the upper end of the scale researchers used.

He described it as a snapshot in time, a scientific survey intended to spark conversation, deliberation and community action.

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WESTERN STUDY

In a parallel study at Western University, researchers are in the final phases of a project that looks at lake stressors during the past 50 years. It then projects four different scenarios for the next 50 years.

Irena Creed, professor of biology and Canadian Research Chair in watershed sciences at Western, said the locally led study has included a small army of researchers throughout the Great Lakes community.

It analyzes not just environmental and ecological stressors but geopolitical, governance and demographic factors as well.

Her group will present its findings at the University of Michigan in January during a workshop among policy and research leaders.

“We have to figure out what future we as a community want to push towards,” Creed said.

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Thirty-four Great Lakes stressors were divided into seven categories:

 Aquatic habitat changes, such as shoreline hardening and erosion control structures, port and marina development, and tributary dams

Climate change that includes seasonal, average and extreme temperatures, precipitation, ice cover

Coastal development: Land-based human development, such as residential, commercial and industrial activities

Fisheries management: Changes to Great Lakes ecosystems resulting from fishing pressure, stocking activities, and aquaculture

Invasive species: Changes to Great Lakes ecosystems from invasive and nuisance species in abundances not previously seen

Pollution: Nutrients, sediments, and waterborne contaminants transported from watersheds to the Great Lakes by streams and rivers and atmospheric deposition

Toxic chemical pollution: Chemical pollutants from industrial and agricultural sources development

Main Lake Huron stressors

Decreasing winter ice and increased water temperatures

Coastal pollution

Fewer fish for commercial fishing

Nitrogen and affecting water quality

Mercury and copper sediments in the lake bed

PCBs

Main Lake Erie stressors

Invasive species such as round goby and zebra and quagga mussels

Nitrogen affecting water quality

Phosphorus causing algae blooms

Decline of commercial fishing stocks, especially on north shore

PCBs

Mercury and copper sediments

(Source: GLEAM Project, University of Michigan)

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For more information:

http://www.greatlakesmapping.org/home