Climate and Water Issues in the Athabasca River Basin: Presented by David Schindler

David Schindler is the Killam Memorial Professor of Ecology at the University of Alberta. From 1968 to 1989, he founded and directed the Experimental Lakes Project for the Canadian Department of Fisheries and Oceans near Kenora, Ontario, where he pioneered the study of freshwater lake systems and helped convince governments in Canada, the USA and Europe to legislate controls on acid emissions and phosphorus detergents. His current research interests include the study of fisheries management in mountain lakes, the biomagnification of organochlorines in food chains, the effects of climate change and UV radiation on lakes, and global carbon and nitrogen budgets. During his career, he has headed the International Joint Commission's Expert Committee on Ecology and Geochemistry, and the US Academy of Sciences' Committee on the Atmosphere and the Biosphere. He has also served as President of the American Society of Limnology and Oceanography, and as a Canadian National Representative to the International Limnological Society.

In addition to teaching courses in ecology and environmental decision making at the University of Alberta, David Schindler is an engaged citizen and outspoken environmental educator, appearing before environmental panels, writing letters, presenting to political commissions and legislative bodies, and speaking at public forums. In recognition of his outstanding scientific and public contributions, in 2004 Dr. Schindler was appointed an Officer of the Order of Canada and elected as one of the 100 Edmontonians of the Century.

Athabasca University was pleased to host David Schindler on October 22, 2004 as part of AU's weekly Lunch 'n' Learn forum, hosted by Athabasca University Research Office. Athabasca University 's Dr. Lorelei Hanson, Assistant Professor of Environmental Studies and Human Geography, edited and condensed Dr. Schindler's public talk and slide presentation for Aurora. Dr. Hanson's most recent work examines sustainable rural communities and the sociology and political ecology of agriculture.

During the past two years Dr. Schindler has been conducting research on the changing ecology of the lakes, streams and principal waters of the Athabasca River basin. He spoke about the effects of climate change and industrial pollution on our regional ecosystem and discussed the sustainability of our current treatment of the Athabasca River and its tributaries.

What follows is an edited excerpt of Dr. Schindler's talk.

Today I'll be talking about the Athabasca Basin and some broader issues with respect to water problems on the prairies.

This is a map of Canada's plumbing. The yellow lines illustrate river flows and the black dots are population and industrial centres, and of course both these and all of our agricultural occur in the south. In this country we are always assured that we have so much water with 7.5% of the surface area of Canada being covered by it. But in fact if you look at the distribution of that water, much of this is not accessible to most of us. While we have some river systems that start in the south, much of the water is really in the northern part of Canada. Similarly, while we have over 2 million lakes in Canada, most of them are north of where much of the population lives.

Of particular concern with respect to water in Alberta is the area around Calgary and Edmonton that is increasing rapidly in population and dependent upon a very few river systems. Add to this picture that even in the mid-20^th Century, the wettest period in the past 2,000 years, there was no net outflow from river basin systems like those which feed much of southern Alberta. In short, what we see is that evaporation on average has exceeded precipitation. So the only reason that cities like Calgary can survive is because of flow out of the Rocky Mountains, both in terms of underground aquifers and surface waters. The Athabasca River, the second largest river in Alberta, is also of particular interest because it's the only river in Alberta that doesn't have major water withdrawal from it so far, or any dams on it. Every other major river in this province has been dammed at least once, and in many cases several times.

The first thing to be concerned about in terms of our water supply is climate warming. The media like to quote from a rare handful of climate dissenters to make it look like there's a real controversy over climate warming, when in fact there is very little dispute about the existence of climate change; the debate is over how much warming will occur. There are very few people, with the exception of a few old fossils who haven't done any research in the past 20 years, who think that carbon dioxide and other greenhouse gases aren't part of the cause of climate warming.

If you take all of the world's climate models and plot them, you can see there's pretty remarkable agreement that for the next three or four decades the global average temperature will increase by another degree or perhaps two, or two and a half. But in the center of a continent, those averages are really not what we want to look at.

When one looks at a Canadian climate model, it shows you that in the middle of our continent, by 2050 we would have an predicted increase of 4 to 5 degrees and by 2100, you would see that in northern Canada, there is predicted to be an increase in temperature of over 6 degrees. In the Athabasca region, it is predicted to be 4 to 5 degrees warmer than in the mid-20^th century. So if these predictions come to pass at all, we're in for some pretty severe changes in weather.

This large best of country embraces districts, some of which are valuable for the purposes of the agriculturalist, while others will for ever be comparatively uselss... The least valuable portion of the prairie country has an extent of about 80,000 square miles, and its that lying along the southern branch of the Saskatchewan, and southward from thence to the boundary line,...

Captain John Palliser, London, July 8, 1860

At least for the southern parts of Alberta and Saskatchewan, we've known for a long time that this area is dry because of the journals and work of explorer, John Palliser. As we now know from paleo-ecological studies, Palliser came through this area in year 20 of a 30 year drought. He wasn't too impressed with the potential of Saskatchewan and Alberta for agriculture, but people came anyhow and made a go of it. For a long time people thought Palliser was wrong. I think the evidence now is showing that Palliser was not wrong, people were just lucky.

Most of the concern for Palliser was related to the area bounded by Edmonton and stretching over into Saskatchewan. What this slide (Figure 6) shows is the precipitation amounts that fell in the mid-20^th century for this area. The average evaporation for the southern part of Alberta is 500 to 550 millimetres. So you can see how much we have to make up with water from our mountain flows and our aquifers. The areas that are over the evaporation rate are the water towers in the Rocky Mountains, with the glaciers and snow paths generating flows. But note also that this northern part, including where the Athabasca flows, has only around 400 millimetres of precipitation a year.

People tend to think of climate change as being about a warmer climate with perhaps a little more precipitation, and that sounds like a wonderful combination. What they forget is that as you heat the climate up, evaporation goes up too. These are our calculations for two sites, Edmonton and Ft. McMurray, illustrating increases that have already happened in evaporation as a result of the warming trend. What you see is a 12 or 13 per cent increase over the mid-20^th century mean. If you project another three degrees of warming, which would happen sometime between the middle of this century and toward the end of this century, you see almost a 25 per cent increase relative to mid-20^th century values. There's lots of other statistics for northern Alberta that indicate that the climate is warming, as is the evaporation rate.

This slide illustrates that in Edmonton we've had a 50 per cent increase in frost-free days and a 33 per cent decrease in days that are colder than -20. In Athabasca, there's been a 140 per cent increase in frost-free days and in Ft. McMurray a 23 per cent decline in cold days. Even High Level had a 40 per cent increase in frost-free days. Right at the mouth of the Athabasca at Ft. Chip, there's been a big reduction in cold days, and a big increase in frost-free days. So things are really beginning to happen in terms of the climate changing.

This is another University of Regina study and it illustrates precipitation divided by potential evapotranspiration. The lightest two colors on here represent sub-humid and semi-arid conditions. Under those conditions, crop growth is considerably inhibited by lack of water. The top diagram (Figure 9) is for the mid-20^th century and the bottom graph illustrates the climate change that we are expecting in the mid-20^th century. Note that that second lightest colour increases both along the bottom of the second diagram and up in the north-west corner of the diagram. The implications of this would be more forest fires.

I mentioned the major glaciers as a part of the flow of many rivers in Alberta. If you sum up this flow as a part of the annual flow at the mouth of the Athabasca or any other river, it doesn't add up to much of the overall river flow. But if you look at the flow in July and August in somewhere like the Calgary region, it can be pretty important. This is the Saskatchewan glacier which as we can see retreated about 1.5 kilometres in 75 years. This is the headwaters for the North Saskatchewan.

The worst stake of all is in the Bow River Basin. This is Bow Glacier in 1898, and again in 2002. Comparing the two pictures (in Figure 11) you can see that the ice is disappearing over the top but the tree in the centre is still here, leaning another 90 degrees, but there's only a few twigs missing in 100 years. What we see is a huge decline in the Bow, and even greater decline in the other glacier that is the headwaters of the Bow, the Peyto Glacier. In July/August, at the park boundary as the Bow flows toward Calgary, glacial melt can compose over 50 per cent of the river flow. It's believed, based on a recent Environment Canada study, that the Peyto Glacier has dwindled so far that even with increased warming it can't yield any more water. We think the Bow is close to this, but the data are not good enough yet to do a glacier mass balance at this point.

Then getting to the Athabasca River we can look at the Athabasca Glacier. It too has declined about a kilometre and a half. This is 1923 to 1993. In 1993 we see the emergence of a new lake in Canada. It didn't exist in 1923 as it would've been under the glacier, as would the Ice Fields Parkway.

What I'm going to do next is show you some long term flows and then a detailed pattern for the Athabasca River. It's no surprise that with climate warming and drought for part of the period, as well as human withdrawals or dams which increase evaporation among other things, that we've seen a decline in every river in Alberta. These data are for the May-August period. We went with that four month period as we reasoned that this is the period when there's really high human demand for water, be it agriculture or municipal use of watering lawns, and so on. You can see these two rivers (Figure 13), the Old Man in the south and the Peace in the north, have declined about 40 per cent in the past 100 years.

The worst of the rivers is the South Saskatchewan, which in the year 2000 was only flowing at about 20 per cent. We now have the last three years of data. This river has huge irrigation withdrawals from the Old Man and the Bow, and also lots of dams to hold water back, causing evaporation to increase.

Now let's have a look at the Athabasca. Everyplace there's a red star on here is a long term gauging station. Sunwapta is just below the glacier, so almost all of the water it sees is due to glacial melt. Then we get down into the areas of interest, in particular the oil sands which occur down in this area below Ft. McMurray.

This graph illustrates in blue the May to August flows in 1970. For these gauging sites, the red bars are the flows by 2001. These numbers aren't based on two years, they are based on a 30 year regression line that I'll show you in a few minutes. You can see from this a big decline in flow of about 30 per cent. But as you can see here, Sunwapta has increased because the warmer climate still has more ice to melt. You can imagine once that ice is gone, that little increase is going to occur here either. In other words, we will not be seeing any glacial flows until we get another ice age.

If you look at the water yield, flow divided by area upstream, you can see an equivalent pattern. Again, the only case where there's an increase over that period is where the glacial flow begins. In particular, down here in the oil sands area between Ft. McMurray and Embarass, there are declines of 40 or 50 per cent flow.

This is the flow trend for the upper end of the Athabasca River. Sunwapta increased by 23 per cent over that period.

This is in Ft. McMurray, where we see a decline of 27 per cent. This is the lowest decline we've seen for any river in Alberta, probably because it has the biggest glacier and still has things to melt as the climate warms. Also there's no dams on it, as I mentioned, and no major water withdrawal.

One thing that this lower flow does is increases the time the water spends in a lake. These are four lakes at the experimental lakes area in Ontario, just as an example, because I have long term data for them. This was a period when the climate warmed by 1.6 degrees centigrade from 1970 to 1989. You can see that a lake that used to have its water renewed every five years in 1970 now takes about 20 years for this renewal. What that means is that if those lakes are getting point sources of nutrients, the concentrations of this nutrients will build up to be four times as great simply because there's less washout. This is a really important part of the nutrient budgets of lakes. It's probably part of the reason why for the last several years we've been seeing some big increases in the algal blooms on our lakes.

This is an equation that I published in 1978, indicating a predictor of eutrophic conditions. It's simply the total amount of phosphorus that a lake receives (phosphorus being the nutrient that causes algal blooms in most cases) divided by the volume of outflow. Of course the volume of outflow from a lake is a function of its inflow. When you subtract evaporation from inflow, you get outflow. So most people worry about doubling the input of nutrients because it will cause more algal blooms, but if you half the volume of flow, it has the same effect.

Another factor in what happens is that we have a lot of bad plumbers screwing with the landscape's plumbing. In agricultural areas, as soon as an area is cleared, farmer start dreaming about how to fill in the wetlands. This is typically what happens during dry conditions when water levels are down. People get in and dig around with their biggest equipment and try to fill in those holes, because the wetlands get in the way of farming. You can't grow wheat on wetlands. But there seems to be general lack of understanding that the water standing in those wetlands is to a very large degree what replenishes the underground aquifers. So the same farmers that are out there filling in wetlands are phoning you up five years later in a drought, complaining that their well has gone dry.

There are also some straight temperature effects on water. This is from a U.S. study and it is in degrees centigrade. In some past work that I did, I showed that lake temperature was a near-perfect linear function of air temperature above the lake. So all they've done is go to air temperature predictions from climate models, and project what the water temperatures will be in different areas. For most of Canada, for example Lake Superior along the 49^th parallel, they're projecting a 6 degree centigrade increase in air temperature. Most of the fisheries of these areas are cold water fisheries. Some of them, like lake trout and whitefish, live very close to their thermal limit as it is. The thermal limit of those species is around 23 degrees centigrade, and a lot of the lakes that are our most productive fisheries, like Lesser Slave, for example, normally get up to 19 or 20 degrees. Same for Lake Athabasca. So if we see 5 or 6 degrees of increase, we're going to see some big changes in fisheries.

A lot of these discontinuous permafrost areas are now melting. Once the water drains away, you can see this change in ecosystem type and general collapse of the landscape. So lots of things happening that have damaged the plumbing and threaten to evaporate the water as climate warms.

Then on top of that of course we have industrial development. Here in Alberta we have a lot of human industry right to the northern part of the province. Looks like some sort of arm connecting with the industrial U.S., which probably isn't too far from truth.

In particular, if you look downstream on the Athabasca, we encounter the oil sands. This map shows the projected oil sands projects through to 2010. You can see these light grids each of which is a township or about 100 square kilometres. So we have this vast area variously estimated to directly impact up to 2000 square kilometres that's slated for development. Remember that every barrel of oil produced currently relies on six barrels of water. While some of the plants are projecting that they can get that down to three barrels of water per barrel of oil, it hasn't happened on average so far.

This is what this area is covered with, for the most part; 56 per cent of that area is covered with a wooded fen. It's basically a thick peaty layer with some very old trees growing out of it. The wooded fen acts like a big sponge. If you have a high rainfall or a big snow pack that melts in that area this absorbs it and then releases it slowly, so there's still some flow in the rivers come fall. It doesn't all hit a straight tube and channel off to the river as one pulse in the spring, which is the sort of the thing that we've done to make southern rivers flood.

This is what they call a restored wetland up there. This is from Syncrude's display site. They've had several meetings of wetland scientists, who have all said you can't replace the wooded fen. What Syncrude calls reclamation is more like a golf course where the lawnmower is broken - a hard land with a little pond at the bottom. And only about 2 per cent of the wetland area has been reclaimed. My guess is you won't see much more than that unless somebody puts some pressure on them. Right now the big pressure is to get that money out of the ground, not to reclaim the landscape. I wouldn't be surprised if you could see these pits from a satellite a 1000 years from now.

This is water use in the Athabasca. The blue line is the licensed data that three of my students found for a class project a couple of years ago. What it shows is very little licensed water use exists. This yellow dot should refer to an estimate by Alberta Energy and Utilities Board, not Alberta Environment. The yellow dot is AEUB's projected use of water in 2012. If you look at the oil sands projections, the red bars here are for a 6 to 1 water to oil use. You can see the bars are fairly long because projections vary. The green bars are for a 3 to 1 ratio of water use to a barrel of oil produced which is based on the optimistic assumption by companies like Shell - who last fall announced a new project - that they can meet their objective of 3 to 1 barrels of water used for every barrel of oil produced. Even if that happens, if you look at this scenario, that's still equivalent to about 50 per cent water withdrawal of the winter flow of the Athabasca in that area. However, this huge water withdrawal didn't phase the Energy and Utilities Board as they got the rubber stamp out and stamped the Shell project to go ahead. But it scared the companies enough that they're putting in water reservoirs to store water at high flow to use during winter conditions when low flow conditions might be a problem.

The only regulation we have are the fabled emissions intensities that Ralph Klein and George Bush dreamed up, where you don't have to reduce emissions, you just have to reduce emissions per barrel of oil produced. They're planning to get that down to about half of what it was in the 1990s. Of course, meanwhile, they're going to increase the output of barrels of oil several fold. So our overall greenhouse gases will go through the roof.

So there are a number of reasons why we can expect the flows in the Athabasca to decrease in the next half century or so. First off, glacial flows will decrease. A lot of the winter precipitation is already falling as rain, which you might expect from those climate shifts. And we're getting more frequent winter melts, so that a lot of what does fall as snow disappears during the winter. It's not there for the spring melt period when we'd like to have it in the rivers. For example, the people at the University of Lethbridge project that the Old Man will lose about 30 percent of its snow pack by the mid-20^th century. So there'll be that much less water available in the spring. Evaporation is going to go up, but precipitation isn't going to go up as much. Then we have this huge removal of peat lands, which will cause higher flood flows, but late season flows will probably simply not be there in the small tributaries to the Athabasca. And on top of that, industrial demand.

Let's have a look at forestry. This is the boreal forest. The yellow and green here are the intact remaining forest. Canada still has 57 percent intact, Russia only about half that. But Alberta is the all-time winner - we only have 21% of our original forests left. The others have all been pretty severely compromised.

These are some of the things we've seen happen in the last 50 years or so. I could show you series like this from around Drayton Valley, from around Swan Hills, from around Sundry. This is La Crete, 1950, not a road. The pale areas are peat lands and the dark areas are forests. In 1969, 1980, 1993, where's the forest?

And of course the other factor as climate warms is we'll probably have increasing incidents of forest fire. In fact, it's pretty well doubled already, and the Canadian Forestry Service people indicate that it'll probably double once again by mid-century. So fire is still bigger than harvest, but you can see the amount of harvest here is going up at a pretty relentless rate.

This is some of that area that I showed you near La Crete. Right behind the forest's disappearance they're planting crops already, and of course busily trying to drain these areas as well. I doubt whether agriculture is going to be very lucrative in that area. That's getting pretty close to the Northwest Territories border, although who knows after climate changes enough. The main point I want to make is this forest isn't being replanted. It's gone forever. We have long ago run out of new crop land in the white zone of Alberta, so any big increases are coming out of the green zone. With respect to water, what that does is to pretty well double the output of nutrient that's transferred from the land into water. Remember our waters are nothing but sewers of the landscape.

This is the Red Deer River. If you get rid of that riparian zone that keeps nutrients out of the rivers, as well as silt and pesticides and other things, and just plough right to the edge of the river and channelize all the streams and drain all the wetlands, you create a lot of problems. Then what happens when you get a big rainstorm after you've just manured or put pesticide or herbicides on the fields is it all goes straight into the river. So we're compromising all of our water sheds in a lot of ways.

And this graph (in Figure 38) illustrates this for all of Canada. Look at the increase in nitrogen fertilizer in particular but also note that phosphorus is not far behind.

When I started working on nitrification of lakes in the 1960's and '70's, if you drew a pie diagram like this, the municipal and industrial part of phosphorus release would've been 50 percent. So we eliminated phosphate detergents and we put phosphate removal, so-called tertiary treatment, on most of the big effluents that drained directly into lakes, or in some cases, rivers. So we've shrunk that with one stroke of the pen. But meanwhile we've let agriculture run wild. This is just manure and fertilizer, and doesn't even include the effects of land clearing. So what we did is to trade an easily controlled source of phosphorus, this nutrient that causes algal blooms, replaced it with very diffuse sources, ones that are very hard to control.

There's yet one more player in what happens in these basins. This is pretty typical for the Athabasca basin. Of course we have trails all over the place made for seismic activity, for oil pipelines, for skidder roads, etc. But what it means is that even remote lakes which only people willing to camp out and walk in on skis could fish 40 years ago are now accessible to most people. Anyone who can turn a key can drag a lot of electronic equipment in there, and a big boat and motor, an ice augur in the winter and ask a result the fisheries are being whacked.

So it's no surprise that if you look at all the major drainages of Canada, the fisheries are either in decline or collapsed. The two darker colours here indicate declining for blue, and habitat decline. So a high proportion of the fresh water fisheries in Canada are going just the way of the cod fishery, but no one notices. In the case of Alberta, a lot of lakes have 70 and 80 percent mortality of every year class. If you take 70 or 80 percent of a year class every year for the seven or eight years that it takes a walleye or northern pike to reach reproductive size in these northern lakes, you can see why we don't have any fisheries left.

With respect to water quality, this is what happens. Typically our lakes have four trophic levels topped by something like a pike or walleye or lake trout, that feeds on minnows and other small planktivorous fish. They in turn feed on the crustaceans that normally graze on the algae in lakes, or the so-called phytoplankton. What happens is that if you have four trophic levels, you have a low abundance of algae. If you eliminate the upper trophic level, the planktivores go crazy, as they have in lakes like Lac La Biche, which has a huge population of spot tail shiners. They whack the daphnia, so the grazing power goes down and the lake goes green. If you eliminate all of the trophic levels you can turn it back to a low algal abundance again. This has been documented in hundreds of cases in North American and Europe. It's known as the trophic cascade, the fact that you switch from low abundance of algae whenever you have an even number of trophic levels, to a high abundance when there's an odd number.

This is the key organism, this is daphnia and as you can see they are about two and a half millimetres long. These are very slow moving organisms that are really good targets for minnow size fish and they spend their time filtering algae from the water and eating it. You can see this is the intestinal tract right here. Each one of these animals can filter about 4 millilitres of water a day, and abundances will be up to 100 per litre of water in a lake that fishery hasn't been tampered with.

But what we've tended to do is go into these very clear low algal lakes, get rid of the habitat, the weed beds and snags, and fish out the predators. The planktivores then go crazy. As a result, the grazers that keep the algae down are depleted and as no surprise, the lake turns green. So that's added to all the increases in nutrient sources and the decreases in dilution because of lower water flows. So three factors now.

Figure 45 is Lac La Biche. Most people think of that as a forested basin. But the red is aspen-dominated, and the green is spruce-dominated. The white area here is all farmland. On top of that there's a ring of cottages, as most of you know are pretty well right around the southern part of that lake and a few on the north. Sewage inflow from the town, which goes into this bay via Red Deer Brook, and the black circled basins here are the ones we used to produce that example that I showed you earlier, with these being the ones with the high nutrient flow and these that have a bit of clearing in them but not so much being the ones we consider to be pretty well intact. So lots of things happening to lakes.

This shows you what's happening to the fishery. This gives us a view of the walleye fishery but pike is about the same. They didn't keep good records of sport fisheries until the 1990's, but as this graph illustrates there has been a huge commercial harvest on that lake which amounted to up to 800 licenses. And what we see is that over time because of the walleye harvest over time is that the walleye fishery collapsed. Most other Alberta lakes show exactly the same pattern.

For most Alberta lakes there is very little historic data. So we decided that if we could deduce what had happened to Lac La Biche from fossil records we could have some sense of the history of many Alberta lakes. So in February of 2003 three of us from the University of Alberta went out to get some samples: myself, Alex Wolf from Earth and Atmospheric Sciences and my wife Susanne Bailey. As this slide shows, we took mud cores from Lac La Biche basin, 16 in all. This is about half a meter of mud, which represents over a century of deposition. Things like diatoms that Alex works with, and nutrients are preserved in that sediment as it falls. So if you can figure out the dates of any layer in here, and measure the nutrients and look at the diatoms, you can figure the state the lake was in. So we've done that. We used lead 2-10 decay to get the dates, which we can confirm in a couple of other ways that I won't go into.

This is the flux of total phosphorus into the sediments over time in that lake. You can see why the locals are complaining that water quality has deteriorated in the lake. The very slow transition in phosphorus amounts probably this represents early land clearing and then in recent years we see a huge increase in phosphorus going into the lake sediments.

Nitrogen actually increases as well, but not as fast as phosphorus but the key thing about nitrogen is that it promotes blue green algae, because they're the only group that can fix nitrogen from the atmosphere. Of course this is part of the problem. The algae float right on the surface where they have a lot of atmospheric nitrogen, so they're very visible. These are also the species that cause taste and odour problems, and that produce the microtoxins that we've been hearing more and more about.

So when we look at the plankton abundance, which we can do by looking at pigments preserved in sediments, both chlorophyll and kerotinoids in this case, we see that same huge four or five fold increase in deposition with time. More recently we've looked at the pigments that are indicative of these blue green algae that are the objectionable species. You can see that for three out of the four types of pigments, they've gone up over time as well. So it's pretty obvious what's happened to the lake. I can show you plots like that for pretty well any other lake in the southern part of the boreal forested part of Alberta. It's happening across the board and it is caused by various developments together that are taking place.

I'll show you another example that's of huge concern, and that's Lake Winnipeg, which is the next river basin farther south. It eventually ends up in Hudson's Bay. The Lake Winnipeg watershed reaches all the way to the mountains. The lake is about the same size as Lake Erie, but the watershed is about a dozen times bigger.

Lake Winnipeg has been producing some huge algal booms of blue green algae. Last year they measured 6,000 square kilometres in area and lasted for several months, which resulted in lots of beach closures on the lake.

I studied that lake in 1969. These were the nutrient figures we came up with for nitrogen phosphorus and, as an indicator of algal blooms, chlorophyll.

But look at what's happened in the 1990's. Again, these are some data showing huge increases in algae through the 1990's.

The World Health Organization recommends that there shouldn't be over a microgram per litre of microcystins in water because they cause liver damage. Yet, we have over 2,000 and nearly 3,000 micrograms per litre in some parts of Lake Winnipeg.

This is where all the action takes place. This is the delta of the Red River. Looks pretty wild, but remember that upstream of this are Winnipeg, Fargo, Moorhead, and lots of fertile agricultural land that isn't fertile enough and so has large amounts of fertilizer applied to it as well. As well, about 85% of the wetlands are pretty well all gone and there's lots of channelization. So there's been huge amounts of nutrients that come down the Red river and flow into the south end of Lake Winnipeg. Meanwhile, the flows are down 20 percent from the historical flows. The Red River used to be by far the biggest river going into Lake Winnipeg and so it was the biggest source of dilution. Now it's the second biggest as the Winnipeg River yields more water even though its flow is also down. The result is that the nutrients tend to stay in the lake.

The last thing I haven't mentioned yet that they did is they now have turned Lake Winnipeg into a hydro reservoir. They've partially dammed it at the mouth. So if you look at the red bars you see that where we used to lose a lot of nutrients from that lake, we're now into a period of nutrient retention. So all of those things, reduced flows, damming the lake, and increasing the nutrient amounts, are turning Lake Winnipeg into a very eutrophic lake.

We have some huge problems in terms of eutrophication of our lakes in Canada and in the past several decades we have seen a shift west in this problem. This is an old graph to which I have added some new data. This is Lake Erie in 1974 when the press was calling it dead. The graph illustrates the average concentration of phosphorus in inflow, and the water renewal time, which is the time that it takes to renew the water in a lake. Here's Lake Winnipeg, right up there with Lake Erie. And at the top is Lac La Biche, probably the most eutrophic lake in Canada, at least among the lakes that have been studied. We solved the problems in the east but are we going to solve them here in the west?

So putting all of that together, we've taken basins under mid-20^th century climate conditions with good flow through, nicely forested catchments, which provided lots of cover for fish to hide and healthy predator populations and we've done this to them. We cleared the watersheds, put in lots of animals and fertilized the land. Once we could get boats in we've whacked the predators. And of course to get boats in you don't like weed beds and snags, so we removed those and left no place for fish to hide. So now the planktivores have gone crazy, the zooplankton have gone down, and the lake turns green.

It isn't as if we don't know the science of what not to do. Leave the wetlands alone, leave the riparian areas around the lakes, strategically fence your livestock out of the river or leave a riparian strip between fertilized land, and be careful when you apply fertilizer.

But we still do it this way. So you can't claim that we don't have the knowledge to do what's right, what we don't have is the will.

Just to summarize, the effects of climate will be to leave us with less water, but it'll also leave us with more pollution in the waters that we have. What I see happening is that somewhere in the coming century we're probably going to have a recurrence of one of those long droughts that you can see in that example I showed of previous centuries.

Meanwhile we're increasing human population numbers and we're turning up the temperature. When increases in temperature, that is to say climate warming and its effects on evaporation, come together with human demand we create some real ecological problems that we are going to have deal with here in Alberta and the rest of Canada.

Publications by David Schindler

Recognition and Awards

As a world renowned scientist, Dr. Schindler has received numerous national and international honours and awards including: the Outstanding Achievement Award of the American Institute of Fisheries Biologists (1984), the Frank Rigler Award of the Canadian Limnological Society (1984), the G.E. Hutchinson Medal of the American Society of Limnology and Oceanography (1985), the Naumann-Thienemann Medal of the International Limnological Society (1988), the first Stockholm Water Prize (1991), the Manning Award of Distinction for Innovation in Science (1993), the first Romanowski Medal of the Royal Society of Canada (1994), the Volvo International Environment Prize (1998), the NSERC Award of Excellence in Research (2000), Environment Canada's Vollenweider Lectureship (2001), the Canadian Nature Federation's Douglas Pimlott Award for Conservation (2001), Canada's highest scientific honour, the NSERC Gerhard Herzberg Gold Medal for Science and Engineering (2001) the 2003 Killam prize, awarded for outstanding career achievements. He is a Fellow of the Royal Society of Canada, a Fellow of the Royal Society of London (UK), a member of the U.S. National Academy of Sciences and has received eight honorary doctorates from universities within Canada and the United States.

Publications by David Schindler

Recognition and Awards

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