Lake Winnipeg: Canada’s Great Dead Zone
We need to be honest with ourselves. What we have created is the largest inland freshwater dead zone in the world. At 15,000 square kilometres in area, algal blooms in Lake Winnipeg are now larger than the record 8,500-square-mile area of the dead zone in the Gulf of Mexico. We need to admit that we are nowhere near to solving the Lake Winnipeg problem. Nor are we as a nation taking the problem as seriously as we should.
In his book, The Ripple Effect: The Fate of Freshwater in the 21st Century, Alex Prud’homme clearly describes what is wrong. Dead zones are coastal or inland water bodies in which oxygen levels are low—or what is called hypoxic—a condition caused by excess nutrients in the water. Because they stimulate the growth of micro-organisms called phytoplankton nitrogen and phosphorous are the two main nutrients that contribute to dead zones. While phytoplankton are a natural part of almost all aquatic ecosystems, they do not come to the notice to the average person until their numbers skyrocket in the presence of abundant nutrients to cause what are called “algal blooms” that colour the water green, red, yellow, or brown and block sunlight from penetrating into lake and river water. When phytoplankton die they are consumed by bacteria. This process, however, can take up a great deal of oxygen leaving little left in the water for other living things. Fish diminish in population and aquatic organisms such as crabs have to migrate or suffocate. Other organisms either slow their metabolism or shut down all together. Species unable to move out of these zones die. Once all the oxygen has been removed by bacteria out of such waters, new complexes of bacteria bloom that often have toxic properties that can become a serious threat to public health. That is what is happening in Lake Winnipeg.
The obvious solution to the Lake Winnipeg problem appears simple: stop using so much fertilizer and generating so much manure and restore natural wetland function wherever possible. The problem is that each province and state contributing to the condition of Lake Winnipeg has its own fiercely competitive agricultural agenda. When every agricultural community in the basin is doing everything possible to produce a bumper crop each year, fertilizer companies understandably don’t want to sell less fertilizer and stock producers do not want to produce less. No one wants to be the first to stop knowingly over-fertilizing their land and contaminating water just because algal blooms are growing in Lake Winnipeg. But the fact remains that agriculture that has this kind of effect on land and water is not sustainable over the long term because it diminishes the bio-diversity-based planetary life support system functions upon which all of us ultimately depend for our survival.
The Lake Winnipeg situation demonstrates that we have not only affected the global carbon cycle, we have likely altered the global nitrogen cycle as well. In a warmer climate, nitrogen and phosphorous may end up being as pressing a problem as carbon dioxide. Lake Winnipeg should not have to die before we understand the serious nature of this threat and do something about it.
Bob Sandford is the EPCOR Chair of the Canadian Partnership Initiative in support of the United Nations Water for Life Decade and a member of Canada’s national Forum for Leadership on Water. Sandford was also recently named senior global water policy advisor to the Interaction Council. He recently published Ethical Water: Learning to Value What Matters Most in collaboration with Merrell-Ann Phare (click here to win a copy). This op-ed is part of an ongoing series exclusive to watercanada.net.