We all know, sadly, that the tailing ponds of Alberta's tar sands are so large (and ugly) that they can be seen from space.
But there is another blot upon the geography of Western Canada that is also visible from space: the massive blue-green algae blooms of Lake Winnipeg, the 10th-largest freshwater lake in the world.
Blue-green algae is a plague found elsewhere in Canada, where phosphates have leeched into lakes from fertilizers, animal fecal matter, bad septic systems and other sources. The blooms are making headlines in Quebec, where years of lax law enforcement have produced blooms in dozens and dozens of lakes. Belatedly, the Quebec government has set aside money to combat the plague. Rural municipalities are finally requiring upgrading and/or more regular cleaning of septic systems. It's going to take a long, long time, however, to recover from years of neglect.
In the 1960s, Lake Erie was the site of a big phosphate buildup. U.S. and Canadian governments managed to reduce the flows of phosphate into the lake, which responded.
Lake Erie, of course, is a shallow lake with a mean depth of 19 metres, but Lake Winnipeg is even shallower with a mean depth of 12 metres. There are few towns or cities of any size bordering it, which perhaps partly explains why its degradation has received less attention than blue-green algae blooms elsewhere in Canada. The small population means that pressure from people around the lake can't be the underlying cause of the problem.
Instead, as a recent report from the International Institute for Sustainable Development (IISD) in Winnipeg underscored, the Lake Winnipeg basin is the second-largest in North America, covering nearly one million square kilometres and draining parts of four U.S. states and four Canadian provinces. Waters that flow into Lake Winnipeg - from as far as the Rocky Mountains to the west, South Dakota to the south and the southern half of Northwestern Ontario to the east - empty into the Nelson River system before arriving at Hudson Bay.
The principal man-made contributor to Lake Winnipeg's problems comes from agriculture throughout that vast basin. The IISD reports that slightly more than 100,000 farms dot the Lake Winnipeg basin. They cover nearly 47 million hectares of land and produce $18.5-billion in annual farm revenues. What leeches into a river in Alberta or Saskatchewan or North Dakota can wind up in Lake Winnipeg. The top source seems to be the Red River, which is prone to flooding and drains a great deal of land in the U.S. upper Midwest and Southern Manitoba.
Livestock, whose emissions of methane contribute materially to increases in greenhouse gases, also produce about 166,000 tonnes of phosphorous per year, according to the IISD. Farmers themselves paid about $1.5-billion to purchase fertilizer, a major source of phosphorous and lime throughout the Lake Winnipeg basin.
The contributors to the problem in Lake Winnipeg operate a long way away, so the cause-and-effect relationship is neither seen nor understood by those whose practices contribute to the problem. Similarly, as is always the case in the tragedy of the commons (in this case the degradation of Lake Winnipeg itself), no one person or farm makes enough of a contribution to the problem to be held accountable, so little remediation happens.
The IISD speaks of the ultimate fix being a "green New Deal," but acknowledges that more scientific study is needed to understand better what's happening in Lake Winnipeg and its basin. The institute also has a charmingly naive view of "substantial shifts in production and consumption patterns." They aren't going to happen, not with so many vested interests involved in existing production and consumption patterns. That said, there is plenty of room for using less phosphate, monitoring what is used, and thinking of new wastewater treatment technologies that remove phosphates from waste water. A Vancouver-based company, Ostara, has developed one such technology that has now being used in a commercial phosphorous-recovery plant in Portland, Ore.
As with many large environmental challenges, no single solution will solve the blue-green algae blooms in Lake Winnipeg, Quebec or elsewhere. That the blue-algae blooms in Lake Winnipeg get so large as to be seen from space, however, suggests perhaps more concerted thinking and action are required.
Editor's Note: The International Institute for Sustainable Development reports that there are 100,816 farms in the Lake Winnipeg basin. Incorrect information appeared in the original newspaper version of this column and in an earlier online version. This online version has been corrected.