CHAPTER 6

THE PEACE-ATHABASKA DELTA

The Peace-Athabasca Delta meets all our requirements for a “special place” but it also is included here for another reason. The Delta is an example of a natural ecological system where a human community was integrated into the system but where the natural processes governing the system have been distorted by political-economic forces. As a result, the integration of the ecological system by natural processes has been diminished so that neither the wild species nor the human culture can be well-supported by the natural system.

6 – 1: The Delta is an inland delta, unlike those at the mouths of rivers. Its waters are totally fresh. Although different in detail, it is probably more similar to the Okavango Delta in Botswana than any other.

The Peace-Athabasca Delta is at the confluence of the Peace, the Athabasca, and Birch Rivers where they come together at the west end of Lake Athabasca. Downstream these all join to form the Slave River, which, after entering Great Slave Lake, gives rise to the mighty Mackenzie River — the De Cho.

Map 1: All the waters from the upper watershed of the Mackenzie River, the might De Cho, flow together at the Peace-Athabasca Delta. The Delta provided ecological support for the settlement of Fort Chipewyan for 300 years until the late 1960s.

Map 2: The ecology of the Peace-Athabasca Delta always has been controlled by hydrological variables, including the effects of ice. Electricity markets in distant urban centres intervened as external forces replacing and changing natural processes. This hydrologically-driven ecosystem was forced onto a new trajectory.

The partial substitution of technological interventions in place of natural processes had major effects on the 300 year old Chipewyan culture.

Historically the core area of the Peace-Athabasca Delta covered 440 square kilometres, including the large Lake Claire and smaller lakes, such as Mamawi, all less than 2 metres deep with marshy margins. The subwatershed of the Delta was much bigger, extending to the headwaters of the Peace River in British Columbia and the headwaters of the Athabasca River in Alberta. The area that was strongly influenced ecologically by the Delta was at least 10,000 square kilometres and includes 4000 square kilometres of Nationally Significant Wetlands. The Peace-Athabasca Delta was one of the largest inland, fresh-water deltas in the world. Much of the Delta was covered with sedges and reed grass and slightly elevated banks supported long lines of shrubby willows. The water levels in the Delta historically were controlled by the interactions of the rivers with Lake Athabasca and by the seasonal peaking of flows in the rivers interacting with ice dams, particularly on the Peace.

6 – 2: People have been drawn to the Peace-Athabasca Delta for over 300 years of known history and probably ever since the first people reached the upper Mackenzie watershed.

6 – 3: It is a delta. Shallow waters over water-laid sediments. Fertile and formerly a rich source of ecological support for the human component of the system.

Downstream, the Delta and its area of influence are critical components of the Mackenzie (De Cho) watershed, which drains about 1.8 million square kilometres (1/5 of Canada) and is the largest freshwater inflow into the Arctic Ocean.

Because of its geographic positioning in these watersheds, the Delta and Fort Chipweyan were staging places for exploration west along the Peace, east along Lake Athabasca and north along the Mackenzie. Alexander Mackenzie partnered in setting up a trading post at Fort Chipweyan. He set out from there in 1789 to explore the Mackenzie River thinking that it would lead to the orient but, instead, ended up in the arctic.

6 – 4: Historically the Peace-Athabasca Delta has been highly productive because of shallow seasonal flooding, seasonal dry-down and a base of rich sediments.

The Peace-Athabasca Delta is special for a variety of reasons. Historically, the Delta was a highly productive environment that provided predictable support for the indigenous population of Fort Chipewyan and the local area. That productivity was based in the three rivers, the Peace, the Athabasca and the Birch that came together here and on the widespread seasonal flooding of both the Peace and the Athabasca across the lowlands near that river junction. To supply most of their needs, the native peoples integrated the natural riches of the Delta with those from Lake Athabasca. Wood Buffalo National Park, a United Nations World Heritage Site, contains 80% of the Delta.

The natural production of the Peace-Athabasca Delta was, as always, based on the “Green Magic” of plant production in the marshes. This supported fisheries, muskrat harvest, waterfowl and other birds at the confluence of four major North American flyways, and winter grazing for the wood bison from Wood Buffalo National Park.

Historically, as many as a million waterfowl were estimated to use the Delta. The journals of early explorers suggest that, until recently, the natural processes in the Delta had been unchanged for 300 years. Early inhabitants, the Beaver, the Athabasca Chipewyan, the Mikisew Cree and the Metis could have told us more. They had been living here since long before the fur trade and before the invasion of Europeans.

6 – 5: Globally, riparian, or riverine, systems are predictably rich areas for green plant production. The Nile valley is a classical example. Here, in the Peace-Athabasca Delta, three types of plant production are visible. The lightest green areas have the greatest net annual production — energy available to plant eaters. The middle green areas of short vegetation are intermediate and the darker, textured areas are woody vegetation with the lowest net annual production.

Southern consumers’ demands for hydro-electricity and for oil initiated two major changes that restructured this historic relationship of the people and the natural processes in their environment. First, some other people, many kilometres away in British Columbia, wanted more power from hydro-electricity. In 1967 the W.A.C. Bennett Dam on the Peace River formed Williston Lake in northern B.C. in order to generate that electricity for the urban people of the south. The amount of water flowing down the Peace was severely reduced during the filling of the dam and somewhat after that. But the main problem was changes in the seasons when the water was allowed to flow. Previously, the lowest flow was in fall and winter but, in spring, the natural level of the Peace rose above the level of Lake Athabasca and that flood reversed the outflow from Lake Athabasca. Although the course of the Peace bypasses the Delta to the north, the high annual spring flow also flooded into the Delta and its lakes. Spring flows were high enough to flood ‘perched basins’ that received inflow only from these seasonal floods.

6 – 6: The nutrient-rich silt supports rapid growth of green plants such as these willows but if it is not flooded seasonally, the silt banks will become better-drained and the willows will be replaced by tree species such as aspen and the energy production available to herbivores will decrease.

6 – 7: Historically the production in the Peace - Athabasca Delta has not all been channeled into terrestrial branches for the food chains. Plant plankton fed animal plankton that fed aquatic invertebrates that fed small and then larger fishes.

However, demands for electricity in the south were highest in winter when it was cold and dark, so more water was put through the turbines at Williston Lake in winter and the flow was reduced in spring. Consequently the perched basins in the Peace-Athabasca Delta have only been flooded three times in over 30 years since the Bennett dam was built. The natural peak in flow was removed; the flows were made more constant over the year. Thus, the urban consumers of electricity began to replace and modify the natural processes in the Peace-Athabasca Delta, several hundred kilometres out of their world. Substitution of technical control in place of natural control of the flow in the Peace caused some other problems, too. For example, in winter, the water flowing out of Williston Lake came from deep in the lake where water in winter stays at 4 degrees Celsius. This raised the temperature of the water in the Peace River and gave some fish the wrong idea. Their eggs hatched at the wrong season and the young could not survive.

The second important change for the Peace-Athabasca Delta was on the Athabasca River, the other big river feeding the Delta. Flow in the Athabasca has dropped significantly since the 1960’s. The development of industries to recover oil from the tar sands upstream along the Athabasca River near Fort McMurray, Alberta has both reduced the flow from the Athabasca into the Delta by a third since the 1970’s and has contaminated the water. It takes 3 barrels of water from the Athabasca River to extract one barrel of bitumen from the tar sands. Because the water is contaminated in the process, it cannot be put back into the river without cleaning.

The contaminated water is stored in dirt-banked ponds near the shore of the river, some with dirt banks built to 300 feet above the river. The water in these tailings ponds contains polycyclic aromatic hydrocarbons (PAHs), petrocarbons, naphthenic acids, salts and heavy metals such as mercury and arsenic. The total volume contained in all these contaminated ponds is three times the volume impounded by the Three Gorges Dam, usually considered to be the largest man-made impoundment in the world. Because the water in these tailings ponds is so toxic, it is said that any waterfowl that land on the water never fly off. Propane cannons and scarecrows are used to scare off incoming waterfowl to avoid their mortality. In the spring of 2008, the cannons and scarecrows were activated too late. Thousands of waterfowl landed on the tailings ponds and were killed by the toxic soup they had mistaken for water. Clearly, the processing of toxic wastes produced from oil sands is working on the very brink of ecological catastrophe.

6 – 9: Wood Buffalo National Park surrounds the Peace-Athabasca Delta and is now home to about 4000 bison of mixed genetic stocks from native wood buffalo and plains bison moved here. The herd in Wood Buffalo gain critical winter forage from the sedge meadows of the delta that can contain 20 percent protein even in mid-winter.

6 – 8: The aquatic food chains are invaded by the terrestrial when the most northerly colony of white pelicans go fishing. This area also is the principal breeding ground of Whooping Cranes which also use both aquatic and wetland food chains.

The flow of the Athabasca into the Delta has been decreasing as the recovery of petroleum from the tar sands has been increasing and the quality of its water has been degrading. As climate change affects the Athabasca, the flow is likely to be further decreased.

Adding to the changes to natural processes caused by alteration in flow levels and timing of peak flows, there also is evidence of toxins being delivered to the Delta in the rivers that feed it. Toxic effects have been found in fish in the Slave and related to inflows from both the Peace and the Slave Rivers. Lesions and deformities have been found on fish in the Slave River and in Lake Athabasca. Research scientists have suggested that the levels of polycyclic aromatic hydrocarbons (PAHs) should be studied as possible causes of the impacts on fish. High levels of PAHs have been found in the sediments. Levels of arsenic and of mercury also are unusually high. There also were indications that moose livers were filtering out toxins from wetland forage eaten by moose. Alberta Health and Alberta Environment both question emerging research reports, suggesting that these toxins were always there and that there is no leakage from the tar sand tailings ponds. David Schindler of the University of Alberta, a world leader in aquatic ecology, says that we need to go in and measure what is actually flowing out of the tar sands.

Residents of Fort Chipewyan increasingly became unwilling to eat country foods or to use local surface water. Then, a few months after arriving as Fort Chipewyan’s fly-in physician, Dr. John O’Connor noticed that a patient had symptoms of a rare cancer of the bile duct, a disease that had killed his own father earlier in Ireland. It was a rare disease and those afflicted usually lasted only a few weeks without treatment. O’Connor reported that three Fort Chipewyan residents certainly, and possibly five, died of this rare form of cancer in just five years. One case in 100,000 people was the normal rate for cancer of the bile duct. Discovery of many other unusual cases followed: cervical cancer in a too-young woman, testicular cancer, uterine cancer, lymphoma, leukaemia, Lupus and Grave’s disease (immune system disorders), and colon cancer — far too many cases of cancer compared to average Canadian occurrence rates, according to Dr. O’Connor.

No other northern communities reported any comparable rates of these diseases. The federal government reportedly has started research to study disease rates in Fort Chipewyan and the possible causes. Local residents have jumped ahead and assigned blame to the water they drink and depend on for their wild harvest. Many are importing bottled water. The water of Lake Athabasca, its feeder rivers and the Delta are no longer trusted.

First Nations and Inuit Health say that the drinking water in Fort Chipewyan is safe. Alberta Health and Welfare is unable to find any evidence of relationships between the water quality or traditional foods and human health in Fort Chipewyan. Dr. John O’Connor was censored by Health Canada and by Alberta Health and charged before the Alberta College of Physicians for raising the issue. After more investigation the charge was withdrawn.

6 – 10: The Peace-Athabasca Delta is at the confluence of four major flyways for waterfowl.

A November 2009 report by the College of Physicians and Surgeons of Alberta (File No. 070059) on medical reports from Fort Chipewyan was leaked to the popular press. This report denies that Dr. O’Connor was ever “officially” charged or “gagged” by Alberta’s College of Physicians and Surgeons, thus obviating reports that he had been “cleared”. However, The National Review of Medicine from January 2008 stated that “…while AH&W (Alberta Health and Welfare) is not officially listed on the complaint, their employees continue to assist Health Canada in pursuing action against him.” The Alberta College of Physicians and Surgeons November 2009 report generates a great lack of clarity on Dr. O’Connor’s reports of health problems in Fort Chipewyan but contains some clear findings. These include the following from a February 2009 report on health issues in Fort Chipewyan from the Alberta Cancer Board who found: “A higher than expected overall rate of cancer (51 cancers in 47 individuals versus the expected number of 39)” and “Higher than expected cancers of the blood and lymphatic system (leukemias and lymphomas), biliary tract cancers as a group, and soft tissue cancers.”

Alberta says that it is regulating the processing of water that is returned to the Athabasca River from tar sands industries. Suncor, the most-experienced tar sands operator, says that they have improved their water recycling and that they put less hydrocarbons into the river than is allowed by Alberta regulations. Alberta allows tar sands industries to discharge 150 kilograms of oil and grease per day but Suncor only discharges 20 kilograms. The petroleum producers say that when science provides new information and the province changes the regulations, they will conform. Meanwhile the people and the natural processes in the Delta display clear signs of trauma while the Alberta government and industry simply meet the regulations even if they are capable of doing more. According to elders in the local community, previously they were able to live off the land. Everyone’s needs were met from the waters of the Delta, the feeder rivers and Lake Athabasca. In the last 30 years there have been massive changes in the Delta that are believed to be responsible for many shortages of natural resources that traditionally have been parts of the people’s way of life. Harvests of wild resources, fishes and mammals, have been much reduced since the Bennett Dam was built. The First Nations communities do not know what information to believe or which authorities they can trust and consequently they are being disconnected from their traditional land and resources.

6 – 11: Not only has the Delta provided critical rest and food for an estimated one million migrating waterfowl, it also hatches and raises many of its own.

The changes to the natural processes in the Delta were not just a matter of flooding. As with many natural processes, the complications make predictions difficult without adequate study. In the case of the Delta, that study was not done until after the changes from upstream commercial activities had already impacted the natural processes. Scientists expressed their concerns much earlier. In 1971, Professor Bill Fuller and others organized a “Peace-Athabasca Delta Symposium” at the University of Alberta. Even at that early stage, most of the interacting forces were identified: hydrological complexity, reversing flows, unknown effects of ice, climatic variations, diversity of habitats, effects of opposing physical forces on habitat dynamics, the sociological dependence on natural processes, and the umbrella effects of legal and jurisdictional forces. And government scientists responded promptly. By 1974, the Canadian Wildlife Service had published “Landscape classification and plant successional trends: Peace-Athabasca Delta” that mapped and classified the complexity on the ground that was already changing under the influence of the W.A.C. Bennett Dam. But not until 1993 was a memorandum of understanding among the First Nations, the Territorial and Provincial and Federal governments, completed to clear the way for the “Peace-Athabasca Technical Studies Final Report” (1996) that promised progress “Towards an Ecosystem Management Plan”. Unfortunately, starting repair more than three decades after the ecological and sociological impact was delivered means that a lot of remediation is required.

6 – 12: Alexander Mackenzie was a partner in the first trading post at Fort Chipweyan just after first contact of the First Nations with Europeans.

6 – 13: As happened throughout Canada’s north, the Hudson Bay Company introduced the commerce of bartering as the first economic-political distortion of natural processes that had significant ecosystem effects.

The Peace-Athabasca Delta and all its ecological and sociological dependencies were a hydrologically-driven system. Effects on natural hydrological processes should have been the first priority in understanding and predicting downstream effects of a dam on a major river. We must ask, was the decision to ignore this clear imperative based on engineering and science, or was it a political decision involving cross-border effects that would impact only sparsely settled areas? After three decades, the science and engineering were allowed to emerge in the 1996 Final Report.

Just as in other pulsed ecological systems, the natural processes of the Peace-Athabasca Delta depend on the periodic peaks and troughs in the pulsing force. In the Delta, that force was the flow of water in the feeder rivers, in particular, the Peace River. The spring peaks in the flow of the Peace sent a wall of water upstream on the Slave River reversing the flow between the junction of the Peace and Lake Athabasca. That flooding refilled the Delta, including high, perched wetlands, and began another cycle of flooding and then drying down.

Flooding in spring, with its load of nutrient-rich silts, enhanced the “green magic” of all the marsh and sedge meadow plants, producing the food base for all else living in the area. Drying down, often totally, enhanced the decomposition of the plant matter deposited from the spring growth. Removing the water from that organic matter and exposing it to the oxygen of the air, often at high temperatures, decomposed the organic matter and resupplied nutrients for new plant growth. Otherwise, shallow marshes soon would fill with organic matter. This seasonal alternation of wetting and drying favours pioneer plants. In the Delta, most pioneer plants are herbaceous, not woody, excepting shrubby willows. Pioneer plants are mainly living, growing tissue that contributes to the “green magic” production of the plants. Without the pulses of water flow, willows and aspens and prairie grasses moved in and turned the shallow wetlands into wet prairies.

The wood in woody plants has no “green magic”. It lives off the proceeds from the parts of the plant that do have the ability to trap new energy. Consequently, part of a woody plant actually uses up part of the plant’s production, leaving less to feed plant-eaters such as muskrats, moose and wood buffalo. So, in the longer term, the pulsing of the system is responsible for stability of the system at a high rate of total production. Such ecologically productive systems are able to support humans as part of the system.

Understanding the disruption of natural processes in the Delta by the dam in British Columbia requires some more interesting details about these pulses in water flow. Although the historic peak spring flows in the Peace River reached heights above the level of the bottom of the Delta, they did not reach high enough to flood many important parts of the Delta. These higher areas had “perched’ water tables — ground water perched at levels above all the surrounding water levels. Yet the Peace had always refilled these perched water tables each spring.

The trick was ice. Under natural flow regimes, the ice in channels in the Delta formed when the water level was at its low winter level. When the flow peaked in spring, water pressure under the ice literally exploded the ice upward, forming big ice dams. These ice dams caused the water level to rise enough to flood even the highest of the perched water tables in the Delta. Recently, the same role of ice dams has been recognized as the mechanism enabling annual reflooding of ‘perched’ wetlands in the Mackenzie Delta.

6 – 14: Fort Chipewyan was the first settlement in Canada outside New France and the Great Lakes basin. Its settlement predated the fur trade and resulted from the richness of the Delta, not the location of a trading post.

More recently, the flows allowed out of the Bennett dam were increased in winter, so when the ice formed in the Delta, it did so at the surface of those higher water levels. In addition, the regulation of flow at the dam reduced the spring peak flows. Combined, these two changes moved the ice higher in the channels, reduced the force of the spring flood under the ice and reduced the explosion of the ice by the forces of the water under it. This reduced the formation of ice dams in the Delta that historically had formed with spring flooding. Lack of ice dams prevented complete flooding of the Delta, especially the higher, perched ponds. Consequently, the Delta dries down so much in summer that the plant production is reduced. Some plants are replaced by other species. The production of all other species, such as muskrats and ducks that fed on the “green magic” of the Delta plants was reduced. The impact affected all components of the system, including the people of Fort Chipweyan who had integrated themselves into that ecological system. In the 1970’s attempts were made to relieve the water shortage problems by installing weirs to regulate water levels in selected areas. These were “band-aid” repairs and many were removed four years after installation. To more thoroughly relieve the impact of the dam it has been recommended: that the Bennett Dam release more water in spring to increase ice-damming in the Delta; that artificial ice dams be considered for flooding specific perched basins; that further hydrologic modelling of the Peace River watershed be conducted to link releases from the Bennett Dam to ice dynamics and to floods in the Delta; and that an integrated ecological monitoring program be mounted for the Delta.

Apparently there is little hope of restoring the natural processes of the Delta to their historic norms. The Bennett Dam, a poorly thought out development project of four decades ago, encountered an improved set of national values at the turn of the century. We now want to repair the ecosystem but the damage to the natural processes of the Peace-Athabasca Delta cannot be fully repaired.

The Delta was a fully integrated ecosystem, including humans. Our actions and poor planning have begun to reduce the power of the most basic natural processes and shift that power over to technological interventions that are guided by market forces. The following chapter will look at an ecosystem where almost all natural processes have suffered that fate.


Image Sources — Chapter 6

Image Photographer Location
1JAPeace-Athabasca Delta, AB
2JAPeace-Athabasca Delta, AB
3JAPeace-Athabasca Delta, AB
4JAPeace-Athabasca Delta, AB
5JAPeace-Athabasca Delta, AB
6JAPeace-Athabasca Delta, AB
7JAPeace-Athabasca Delta, AB
8JAPeace-Athabasca Delta, AB
9GMWood Buffalo National Park, AB
10JAPeace-Athabasca Delta, AB
11JAPeace-Athabasca Delta, AB
12 JAFort Chipewyan, AB
13JAFort Chipewyan, AB
14JAFort Chipewyan, AB


Maps – Canadian Wildlife Service, Report Series No. 30 1974 and from Peace-Athabasca Technical Studies Final Report 1996
JA – copyright © Jeff Amos
GM – copyright © Gray Merriam