More products of ever-warmer winters: harmful algal blooms, invasive species

Ice coverage on the Great Lakes was historically low this winter, but experts say the unprecedented ice levels are just one issue the lakes are facing as global warming progresses and unseasonable winter temperatures become more likely.

Alongside the lack of ice coverage, the lakes also are facing the proliferation of invasive species, strain on the lakes’ natural, temperature-driven stratification process, and, perhaps most in the spotlight, the rise of toxic algal blooms.

“The projections are not great,” said Nancy Tuchman, founding dean of Loyola University’s School of Environmental Sustainability. “The projections of average surface water increase in temperature across the Great Lakes by 2050 is 7 degrees Fahrenheit, and by the end of the century, it’s 12.1 degrees Fahrenheit. This has enormous impacts on the structure and function of the Great Lakes and the organisms that live in (them).

Harmful algal blooms have been a problem in the Great Lakes for well over a decade, threatening water quality for fish and humans alike. Some of the blooms are so massive they can be seen in satellite imagery.

While the blooms are most concerning in the shallow waters of Lake Erie and in confined areas along Lake Michigan such as Green Bay, they have cropped up in the Chicago area, Tuchman said.

The Illinois Environmental Protection Agency routinely monitors public water supply intakes for potential blooms, including a handful of sites along Lake Michigan.

The toxic growths are not only the product of warming waters, but of excess nutrients fueled by agricultural fertilizer runoff — most notably animal agriculture. One of the largest sources is confined animal feeding operations, known as CAFOs, where thousands of pigs, cows and chickens are kept.

“When thousands and sometimes millions of animals are put in one facility with a very small geographic footprint, those animals create waste, and that waste has to go somewhere,” said Katie Garvey, staff attorney with the Environmental Law and Policy Center.

Because waste is expensive to transport — and to treat — it typically ends up traveling from the land to nearby watersheds via stormwater runoff or subsurface draining systems, delivering the excess phosphorus and nitrogen that harmful algal blooms love.

Some states have put policies in place to limit the maximum amount of nutrients entering the lakes. For instance, Ohio began regulating nutrient runoff last year as a result of a lawsuit against the federal EPA by the Environmental Law and Policy Center and Lucas County, which surrounds Toledo.

But Garvey said it remains to be seen whether the emerging policies will be effective, and there’s still a ways to go to tackle the enormity of the issue, especially with the fundamental problem of unregulated industrialized food systems left untouched.

“The critical thing that states need to do is acknowledge that not all farms bear the same responsibility for water pollution,” Garvey said. “The largest of the large livestock facilities, which are making products at an industrial scale, need to be treated like other industrial-scale polluters. They need to be required to manage their waste responsibly.”

• Jenny Whidden is a climate change and environment writer working with the Daily Herald through a partnership with Report For America supported by The Nature Conservancy. To help support her work with a tax-deductible donation, see

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