Niagara Gazette — TRAVERSE CITY, Mich. — The U.S. and Canada should crack down on sources of phosphorus runoff blamed for a rash of harmful algae blooms on Lake Erie, an advisory agency said Thursday. The algae produce harmful toxins and contribute to oxygen-deprived "dead zones" where fish cannot survive.
The International Joint Commission said in a report that urgent steps are needed to curb runaway algae — a problem that led both nations to reach their first agreement to improve Great Lakes water quality more than 40 years ago, when some considered Erie ecologically dead.
Tougher standards for municipal and industrial waste treatment produced improvements by reducing the flow into the lake of phosphorus on which algae feeds. But the problem began worsening in the late 1990s. In 2011, the largest mass on record formed in the lake's western basin, eventually reaching more than 100 miles from Toledo to Cleveland.
"What happened in 2011 was such a shock that people realize more of the same is just not tolerable," said Lana Pollack, chairwoman of the commission's U.S. section. "If we can get the governments to take action on this report, it will make a big difference."
The report says different sources of phosphorus runoff have emerged — primarily large farms, where manure and other fertilizers are washed into tributary rivers during storms and snowmelt. They accounted for more than half of the phosphorus that reached the lake in 2011, while one-third came from smaller farms and nearshore communities as well as city sewers.
More intense storms likely caused by climate change are sweeping more nutrients into the lake, the report said. Additionally, unlike decades ago, much of the phosphorus dissolves in water, making it easier for algae to consume.
The report sets targets for sharp reductions in phosphorus runoff over three to six years, including a 46 percent decrease in total phosphorus and a 78 percent cut in the dissolved type for the lake's central and western basins.