A vast blanket of algae, which could threaten tourism and fisheries and affect drinking water, bloomed in Lake Erie because of the huge amount of phosphorus from the fertilizer overuse.

The International Joint Commission informed the authorities that the use of fertilizers should be limited as it is swept by rains from farms and lawns to the lake. It suggested that crop insurance should be tied to farmer's use of fertilizers and that Ohio, Ontario, and Pennsylvania should prohibit sales of phosphorous-based lawn fertilizers.

The commission's proposal will surely encounter strong opposition from fertilizer manufacturers and agricultural organizations. Especially from the groups who have already filed an appeal in federal court to bar the Environmental Protection Agency from controlling farm-related pollution from phosphorus and other hazardous chemicals along the Chesapeake Bay.

"The long-term potential impact on fisheries is something we're really worried about," said Donald Scavia, a scientist at the University of Michigan's Graham Environmental Sustainability Institute, to New York Times.

The biggest farm source of phosphorus is the fields along the Maumee River watershed in Indiana and Ohio. However, the chemical can also come from leaky septic tanks and storm sewers.

To bring back the lake to its original state, the commission, which studies and regulates water use in lakes along the edge of the United States and Canada, use of phosphorus in surrounding fields must be reduced by 39 percent.

In order to achieve the 39 percent target, regular residents in Ohio, Ontario, and Pennsylvania, must limit use of fertilizers in their lawn except for the first growing season of new lawns, or when the phosphorus content of the soil is too low. Inspection of septic tanks and replacement of leaky ones are highly recommended, too.

Farmers in the lakeside states and provinces, on the other hand, must stop spreading fertilizer on snowy or frozen grounds because when it melts, there is a high chance for the phosphorus to be carried away. They must also limit spray of fertilizer during the fall season.