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The Rochester Democrat and Chronicle has an extensive report on how zebra/quagga mussels, algae and phosphorous are working together to create a ring of pollution along the shallow, near-shore sections of Lake Ontario.  Many of the same problems plague Lake Erie as well.  Excerpts and link:

Phosphorus, a highly reactive element obtained by mining phosphate rock, was named a pollutant of concern by the U.S. and Canada in their 1972 Great Lakes Water Quality Agreement. An ingredient of fertilizer and cleaning compounds, phosphorus was discharged into the lakes in large quantities. The agreement called on the two nations to tighten control of phosphorus at sewage treatment plants and reduce phosphate additives to laundry soaps.

Those steps and more were taken. For example, New York was among several Great Lakes states that had essentially banned phosphates in laundry soap by the mid-1970s.

Billions of dollars were spent in the Great Lakes to improve sewage treatment plants’ ability to control phosphorus and other pollutants and to minimize raw sewage overflows into water bodies in cities where wastewater and stormwater shared sewer pipes. In Monroe County, about $500 million, most of it federal money, was spent to build huge tunnels to prevent such combined sewer overflows.

The results in much of the lake were impressive. Water quality improved dramatically, and fish and other aquatic species rebounded. Springtime phosphorus levels in the lake’s deep waters, which in the 1980s were often above the international target of 10 micrograms per liter, have been less than half that level in recent years, according to EPA data.

“Off-shore — two, three, four miles and more out — the water is very transparent. It’s clear down to 30 to 35 feet,” said Joseph Makarewicz, a distinguished professor of biology at the State University College at Brockport and the U.S. chief scientist on the research project.

As phosphorus tapered off, so did algae.

“It appears that the severity of complaints declined through the 1980s. And when you got in the later parts of the ’80s, it didn’t seem to be such a problem any more,” said Todd Howell, Great Lakes ecologist with the Ontario Ministry of the Environment in Toronto and chief scientist for the Canadian portion of this year’s research.

But in the late 1990s, citizen complaints about fouling of beaches and shorelines began to recur. When Howell surveyed the lake bottom in 2000, “there was scads of the stuff there,” he said, and complaints became even more frequent after that.

No systematic survey has been made in U.S. waters, but there is no doubt that the algae is running wild again.

Full story:

http://www.democratandchronicle.com/apps/pbcs.dll/article?AID=/20080824/NEWS01/808240353/1002/NEWS

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