All right. I'm going to talk about the water levels.
The water levels in Lake Michigan have fluctuated in approximately 30-year cycles over the past century. They range between 175 and 177 metres, but with a long-term mean of about 176 metres, above sea level.
One of the many consequences of global climate change is there are lower than normal water levels in the Great Lakes, and we are seeing this now. For lakes Huron and Michigan, which are essentially two lobes of the same lake, water levels have been at or below the long-term average since 1999. The mean water level between 1999 to 2013 is 176 metres, which is an average reduction of 53 centimetres below the long-term mean. No other of the Great Lakes is associated with as large or as long a reduction.
There are many consequences of this, but the sustained low water levels have had immediate and devastating effects on the quantity and the quality of the fish habitat in coastal wetlands. Some of these negative effects have included up to 24% loss in breeding and nursery habitat, because they are no longer accessible to migratory fish. There is deterioration in the habitat structure related to disappearance of some of the submergent vegetation in the deeper water and a reduction in the species richness of fish and plant communities. If water levels were to drop to 174 metres, which is predicted by the global circulation models, access to another 50% of the wetlands now extant will be lost.
Even if wetlands don't dry up, we are also concerned about the thermal quality of these wetlands. We have monitored the water temperatures in some of these embayments and have found that the temperature of the water that is used by pike is approaching 27.5°C, which is the point at which the fish stop feeding. We know when they don't feed, they're not growing and they start to die.
There is very little information on how water temperature in these nearshore habitats is changing. There is not a single monitoring system in the whole of eastern and northern Georgian Bay that is now being monitored by government. This highlights the need for more targeted research to understand the threat of warming temperatures and low water levels on the health of nearshore embayments.
I'm going to skip now to talk very briefly about our seeing the same sort of problems that Dr. Taylor was talking about with regard to the nearshore algal blooms in Georgian Bay. This is a big problem, because these are the kinds of things we expected to see in the lower lakes but never expected to see in Georgian Bay.
We're now seeing algal blooms in some of these embayments, and anoxia developing below eight metres from the middle of June until the end of September. All of these are happening because, we think, of association with the low water levels. But there's also increased development, and there are aging septic structures that are also contributing nutrients. None of these is being regulated in such a way that we can actually know what exactly is happening.
A lot of this is really a plea for you to make an effort to establish some monitoring specific to the Georgian Bay context, because it's very clear that you cannot just extrapolate information from Lake Erie, a system that is very shallow and which has a lot of people living in it, to something that is on the Precambrian Shield and that has a very low nutrient concentration.
I want to finish off by telling you that almost all of the work I have done in the last 10 years has not been funded by government agencies. It has been funded by small charitable organizations and private foundations. I think there is a bigger role that governments should be playing in making sure that some of these things are actually monitored and carried through over the next 20 years.
Thank you.