Thank you, sir.
I guess I won the prize of going first because I'm the oldest. I'll tell you what that led me to think about in the Great Lakes.
My short talk is called “The Rise and Fall, and Rise Again, of Pollution of the Great Lakes”.
When I worked at the Canada Centre for Inland Waters on the Burlington side of Hamilton harbour, we were very excited when the Canada-U.S. Great Lakes Water Quality Agreement of 1972 was signed. The scope was broad and it was based in large part on our scientific efforts. The need for a major cleanup was obvious, and the two countries, Canada and the U.S.A., Ontario, and eight states made clear commitments to pollution control programs in the agreement and in the related Canada-Ontario agreement.
Two main problems had been identified. The first was over-enrichment by the nutrient phosphorus, causing major algal blooms, which subsequently resulted in dead areas at the bottom of Lake Erie, and nearshore problems in practically all the lakes, but probably not Lake Superior. The second problem was a pervasive plague of toxic chemicals contaminating fish, water, and sediment. These problems were tackled vigorously by building sewage treatment plants for all municipalities and industries, and regulating phosphorus in detergents and some toxics, such as PCBs and the pesticide DDT.
This effort had wonderful effects, and by the late 1980s the main body of the lakes was pronounced healthy again. But after that, in both countries the governments relaxed a bit, and reduced both staff and attention to comprehensive science and monitoring. They considered, and many other people did, too, that the job was completed and well done.
Unfortunately, along with the inattention and staff reduction came a serious backsliding over the past two decades in the condition of the lakes. Algal blooms on Lake Erie, especially blue-green algae producing toxic cyanobacteria, are now seen as worse than before the big cleanup that began in 1972.
How did this occur? Well, the International Joint Commission has determined in its report this year on Lake Erie that more diffuse sources of pollution rather than the point sources from before are mainly to blame; that is, more often there are large quantities of phosphorus in runoff from urban and suburban areas and farmlands.
Some of this increase is due to changes on the ground. These include bigger sprawling suburbs with fertilized lawns and many pets, and more intensive agriculture using bioavailable fertilizer for things like the corn-soybean rotations that are common now.
Such changes leave more phosphorus on the ground to be dissolved in the runoff and loss of the protective coastal wetlands allows more rapid discharge to the lakes.
The contribution of the changing climate has also been critical. On the U.S. side of the basin, heavy rain events that produce runoff have increased in frequency by 27% since the 1960s. In a study I did recently for the Grand River Conservation Authority in Ontario, which also discharges to Lake Erie, it was found that the annual number of surface runoff events has increased 18% from the 1970s due to more frequent heavy rains and winter snowmelt periods.
Intense precipitation events increase in a warming climate, and the theory shows it to be by 7% per degree Celsius of temperature increase in the atmosphere.
This committee has already heard—I've seen the testimony—from representatives of Toronto and Hamilton about the impacts these heavier rains are having on polluted runoff and floods from their territories.
One of the consequences of this combination of changing land use and changing climate is that much larger quantities of the nutrient phosphorus is carried in the runoff waters, and much more of that phosphorus is of the dissolved bioavailable type.This is a double whammy, both more large flow events and higher concentrations of dissolved reactive phosphorus in those flows.
When these polluted flows reach the warming waters of the Great Lakes, large algal blooms are produced. An example on Lake Erie is on the cover of the 2014 International Joint Commission report, where you see a boat trying to plow through a huge algal bloom. I didn't bring copies of this because I was told by IJC that they had sent copies to all members of the committee.
This re-eutrophication, which is what the process is called, is also beginning to be felt on the shores of Lake Ontario, Lake Huron, and perhaps Georgian Bay as well. The report of the IJC documents the preventive actions that must be taken to reduce phosphorus sources on farmland and in urban areas from ending up in the lakes, and I would commend to you the proposals they have.
In addition, a new era of toxic chemical pollution has also been documented. For highly toxic mercury, after reductions from 1970 to 2005, we now see concentrations on the rise again in some fish and fish-eating birds, such as loons. Coal-fired electricity generating plants in the U.S.A. continue to be a major airborne source of mercury to the Great Lakes, although Ontario has thankfully reduced its number of coal-burning power plants.
The good news is that serious health and ecosystem threats from DDT and from PCBs have decreased as a result of regulations, as shown by analyses of herring gull eggs at Burlington in a program that began in 1972.
But there are a host of new contaminants, not removed at conventional sewage treatment plants, finding their way to the lakes. These include pharmaceuticals, dumped or excreted. There are small but growing concentrations of anti-inflammatory drugs in Lake Erie's open water, far from shore. Antidepressants are observed in Lake Ontario and antibiotics down the St. Lawrence River. Endocrine-disrupting substances are found in Lake Huron.
The gender composition of a community near Sarnia, Ontario is changing, with only half as many boys as girls being born. We've seen similar kinds of changes in fish communities—more females and fewer males. Toxic flame retardants are on the increase.
But on a very positive note, recent research has shown that ozonization, or using ozone, in water and waste water treatment could remove many of these newer pollutants and help clean up our waters.
In summary, our generation, through our governments, holds in trust these vital waters for all to use and for future generations. But if we want the Great Lakes-St. Lawrence system to be healthy, fishable, drinkable, and swimmable, we must renew our commitments. This means an increased commitment to monitoring and science, and a commitment to undertake control measures based on scientific findings. We owe this to ourselves, to our grandchildren, and to their children.
My colleagues will tell you some of the ways we can move forward.
Thank you.