It’s a toxic green menace so big it’s visible from space. Looming especially large last August, it has tainted the drinking water of thousands of people, killed fish and created noxious “dead zones” in Lake Erie.
Massive algae blooms are the culprit – spreading a sickening scum across vast expanses of fresh water in the warm weather of summer. And they’re getting worse.
Canada and the United States are pushing back against this slimy threat by agreeing to reduce phosphorus flowing into affected areas of Lake Erie by 40 per cent. The target was announced last Monday. It’s a welcome first step but meeting this goal will require tough and determined action.
Phosphorus, a key ingredient in fertilizer, feeds the growth of harmful algae. Dozens of experts on both sides of the border have used computer models to calculate that a 40-per-cent drop in levels of the chemical should bring Erie back to health.
Unfortunately, that kind of reduction isn’t easy to achieve. The main source of the phosphorus pouring into Lake Erie is runoff from farmers’ fields and manure piles. It makes it far more difficult to cut than the filth pumped out by a few big factories.
Nonetheless, it’s vital that flow is diminished. A toxic algae bloom contaminated the drinking water of 500,000 people in Ohio alone in 2014. And beaches are commonly closed due to the health threat posed by giant blobs of algae. They can produce a liver toxin called microcystin. Swimming in tainted water can irritate the skin, sicken humans, and kill dogs.
Fish are affected in a different way. When algae blooms start dying off they’re broken down by bacteria. This decay process uses up oxygen on a massive scale, sometimes leaving “dead zones” in the water where fish are unable to survive.
As the shallowest and warmest of the Great Lakes, Erie is especially at risk. Yet it’s a vital natural resource, providing drinking water to more than 11 million people as well as opportunities for recreation, transportation and wildlife preservation.
U.S. and Canadian officials have set a deadline of February 2018 to develop specific action plans designed to cut phosphorus by the required level, focusing their efforts on Erie’s central and western zones where the threat of algae is greatest.
Convincing farmers to spread less phosphorus-laden fertilizer on their fields would be one way to proceed. It may be necessary to switch to different crops as well as finding ways to capture or limit runoff. Whatever the approach, it’s important that authorities in charge of cutting phosphorus act in a firm and timely manner.
Erie and the other Great Lakes face tremendous challenges. As well as out-of-control algae there’s serious concern about declining water levels, warming due to climate change, shoreline development pressure, and invasive species, especially a new threat posed by Asian carp.
Millions of Canadians and Americans depend on this extraordinary resource. Their governments mustn’t leave them unprotected.