Lake Erie has been in the news lately, but for the wrong reasons. Instead of stories about the lake’s continued recovery from industrial pollution in the 1960s or about popular beaches or fishing locations, the news has been about pollution from excessive algae growth and the temporary ban on water use for 400,000 people in Toledo, Ohio.

During much of the 1990s, Lake Erie was seen as an environmental success story. Once considered a “dead lake,” due to industrial and urban pollution, the lake made a rapid comeback after pollution flowing from factories was cut dramatically. The Clean Water Act put teeth and money behind the cleanup of industrial pollution.

So-called source pollution from factories and older sewage treatment plans was effectively cut during this earlier cleanup efforts. Now, more diffused sources of pollution, mostly fertilizer run-off from large-scale farms and manure from livestock feed lots, has phosphorus levels steadily climbing in the lake. And with excessive levels of nutrients, so-called blue-green algae blooms have recurred in recent years, along with the algae’s production of the toxic microcystin.

Toledo is most vulnerable because it draws its water from the western end of the lake, where the water is shallower, allowing summer sunshine to warm the water, creating ideal conditions for algae growth.

Toledo’s location at the mouth of the Maumee River also makes it particularly vulnerable to algae-related pollution. About 75 percent of the Maumee River watershed includes agricultural production and the river carries more sediment and phosphorus than any other Great Lakes tributary. Overall, Lake Erie takes in more runoff-carried phosphorus than any other Great Lake, receiving about 44 percent of the total of all five lakes.

Lake Erie’s problems with excessive algae growth are not unique. Lakes in China and New Zealand have similar algae issues. In the U.S., the Chesapeake Bay has suffered from agriculture-related algae pollution. Florida’s Lake Okeechobee, surrounded by large farms, citrus groves and golf courses, also suffers green algae pollution.

As with most problems that have developed over decades, there is no quick fix. Years of unchecked flows from of agricultural runoff into streams and rivers that flow into the lake have left behind a layer of phosphorous-rich sediment that will take years to return to normal levels. One estimate suggests that if farm runoff were to be cut by 80 percent, it would still take at least 20 years for the phosphorus in Lake Erie’s sediment to be depleted enough to not trigger toxic algae blooms.

The successful cleanup of Lake Erie from industrial pollution resulted in a rapid recovery and a good-news environmental story for the region. But cutting pollution from large factories and municipal sewage plants was achieved relatively easily became the sources of the pollution were identifiable and limited. But with today’s agricultural pollution, the sources are far more numerous and extend throughout the wider area of the lake’s watershed, which extends from central Indiana to lower Michigan, in addition to shoreline areas of Ohio, Pennsylvania, New York and Ontario.

Failure to start taking stronger steps to reduce phosphorus pollution in Lake Erie will mean more toxic-algae blooms, more drinking water restrictions for cities along the lake and more beach closings due to pollution. None of that is good public relations for the Great Lakes region Not only will future algae blooms inconvenience people living along the lake’s shores, it also will hurt tourism, much like the recent oil spill in the Gulf of Mexico that kept tourists away.

The news coverage of algae pollution with pictures of disgusting green sludge in drinking glasses and the water ban for Toledo should fuel public and political pressure to step up efforts to dramatically cut phosphorus coming into Lake Erie.