The International Joint Commission:
The binational agency established under the Boundary Waters Treaty of 1909
between Canada and the U.S
Responsible for regulation of flows on the St. Mary’s and the St. Lawrence Rivers
Lake Michigan flows to Lake Huron through the Straits of Mackinac.
Michigan and Huron standing at the same elevation.
No artificial controls on the St. Clair and Detroit Rivers that could change the
flow from the Michigan-Huron Lakes system into Lake Erie.
Outflow of Lake Erie via the Niagara River is uncontrolled except for some
diversion through the Welland Canal
Further regulation by engineering systems could not be justified in light of the
cost and other impacts *** one inch (two and a half centimeters) of water on the
surface of Lakes Michigan and Huron amounts to more than 36 billion cubic
meters of water (about 1,260 billion cubic feet).***
Stratification: layering of water in the lakes due to density changes caused by
changes in temperature.
The density of water increases as temperature decreases until it reaches its
maximum density at about 4° Celsius (39° Fahrenheit)
Thermal stratification, or the tendency of deep lakes to form distinct layers in
the summer months.
Deep water is insulated from the sun and stays cool and more dense, forming a
lower layer called the 'hypolimnion'
- High productivity just above the hypolimnion
- Hypolimnion has less sunlight and is therefore less productive
- Hypolimnion lacks oxygen in central basin of lake erie b/c of
decomposition o organic matter
Surface layer called the 'epilimnion'.
- Supports most life in lake
- Rich in oxygen
Thermocline (middle layer) develops as summer progresses and temperature
differences increase between the layers in which a rapid transition in
Fall surface waters cool, become denser and descend, displacing deep waters
and causing a mixing or turnover of the entire lake
Winter the temperature of the lower parts of the lake approaches 4° Celsius
(39° Fahrenheit), while surface waters are cooled to the freezing point and ice
can form. Temperatures and densities change in spring, another turnover may occur.
However, in most cases the lakes remain mixed throughout the winter
Turnover is the main way in which oxygen-poor water in the deeper areas of the
lakes can be mixed with surface water prevents anoxia
Thermal bar holds pollutants near shore, they are not dispersed to the open
waters and can become more concentrated within the near shore areas.
Plant material is consumed in the water by zooplankton, which grazes the waters
for algae, and on land by plant-eating animals (herbivores)
~ 180 species of fish indigenous to the Great Lakes.
Near shore fish: smallmouth and largemouth bass, muskellunge, northern pike
and channel catfish.
Open water fish: lake herring, blue pike, lake whitefish, walleye, sauger,
freshwater drum, lake trout and white bass.
Erie was the most productive – warm and shallow
Superior was the least productive- deep
Overfishing, habitat destruction or the arrival of exotic or non-indigenous
species, such as the lamprey and the alewife, has lost many native fish species
Chapter 4: Concerns Today
Since about 1960, we realized the harsh implications of some human activities.
The largest categories of impact are pollution, habitat loss and exotic species
Agricultural development, forestry and urbanization caused streams and
shoreline marshes to silt up and harbor areas to become septic.
Domestic and industrial waste discharges, oil and chemical spills and the effects
of mining left some parts of the waterways unfit for water supply and recreation.
Historically, the primary reason for water pollution control was prevention of
Treating drinking water by adding chlorine, as a disinfectant
Humans can acquire bacterial, viral and parasitic diseases through direct body
contact with contaminated water as well as by drinking the water.
Closing affected beaches during the summer when the water is warm and when
bacteria from human and animal feces reach higher concentrations.
Combined sewers contribute to contamination problems during periods of high
rainfall and urban runoff
Sewage collection and treatment systems cannot handle volumes of storm and
sanitary flow untreated sewage, diluted by urban runoff, is discharged directly
into waterways. Expensive to replace combined sewers with separate sewers
Alternative s combined sewer overflow retention for later treatment (lower
costs than sewer separation)
Beach closures have become more infrequent with improved treatment of
Eutrophication and Oxygen Depletion
Lakes characterized by biological productivity (amount of living material they
support)- mostly algae
Oligotrophic- lease productive
Eutrophic – most productive
Variables that determine productivity are temp. Light, depth, volume and
Temps of tributes have increased b/c of removal of shade and some thermal
Nutrients/ organic material entered lake has increased with urbanization and
agriculture nutrient loading with phosphate detergents and inorganic
Phosphates in detergents are a problem when not regulated b/c increased
nutrients stimulates growth of green plants (algae) which eventually die and
decompose Organisms that decompose the plants use up the oxygen
dissolved in water near bottom
Without nutrient loading oxygen levels are maintained
Biochemical oxygen demand (BOD): depletion of oxygen through decomposition
of organic material
- generated from discharges from treatment plants and decaying algae
- big problem in central basin of Erie
- As BOD increases and O2 drops certain species of fish can be killed and
sludge, worms and carp replace them
Foggy water and increase in chlorophyll accompany accelerated algal growth and
Erie was firs to develop eutrophication
O2 depletion in Erie 1920s
Controlling input of phosphorus could control eutrophication
Lower layer of central Erie (hypolimnion) can become anoxic and chemical
processes change “dead zone”
- Western less susceptible to anoxia b/c of wind and too shallow and eastern is
deeper with thicker hypolimnion
Belief that Erie was “dying” cladophors near beaches and turbid water
Toxic Contaminants The dangers of toxic substances in the natural environment were first shown
through the study of pesticide DDT.
Toxic pollutants include human-made organic chemicals and heavy metals that
are dangerous if chronically exposed to small amounts
risk of cancer, birth defects and genetic mutations through long-term, low-level
Toxic substances tend to bio accumulate as they pass up the food chain in the
Concentrations of chemicals such as PCBs may be so low that they are almost
undetectable, in the water
Biomagnification through the food chain can increase levels in predator fish such
as large trout and salmon by a million times
Health and environmental agencies in the Great Lakes states and the Province of
Ontario warn against human consumption of certain fish.
Some fish cannot be sold commercially because of high levels of PCBs, mercury
or other substances.
Fish consumption provides the greatest potential for exposure of humans to
toxic substances found in the Great Lakes when compared with other activities
such as drinking tap water or swimming
Trout from Lake Michigan will be exposed to more PCBs in one meal than in a
lifetime of drinking water from the lake.
At-risk groups of concern: people who rely on fish and wildlife for a large part of
Concerns that exposure to low levels of some contaminants may cause subtle
effects on reproduction, development and other physiological parameters
Effects of persistent contaminants on the immune system, the nervous system,
pre-natal and post-natal development, fertility and the development of cancers.
Disease rates within the Great Lakes basin are not significantly different from
those in other parts of the U.S. or Canada.
Developing fetus and child, the elderly and people whose immune systems are
already suppressed are more susceptible
Some of the chemicals found in the lakes have been shown to be cancer-causing
agents (carcinogens) in high-dose animal studies.
DDT, one of several chlorinated organic compounds that can weakly mimic
estrogen, is under investigation for potential linkages to one type of breast
TCDD, a form of dioxin, to mimic estrogen, with the potential results of
feminization of sex organs in males and disruption in the development of other
sexual characteristics. There are also questions about the effects of estrogen-like
compounds on sperm quality.
Pathways of pollution
Many pollutants are deposited from the atmosphere. Nutrients and toxic contaminants carried and deposited in the lakes in wet and
Atmospheric deposition of a pollutant in the Great Lakes basin was first
recognized with phosphorus
PCBs volatilize out of the lakes, as well as being deposited into them from the
reservoir of chemicals in air masses
Release of pollutants from sediments occurring in Niagara, St. Clair and St.
Mary’s Rivers, in harbors such as Hamilton, Toronto and the Grand Calumet, and
in tributaries such as the Buffalo, Ashtabula and Black Rivers.
Groundwater water slowly passes through the ground it can pick up dissolved
materials that have been buried or soaked into the ground.
Loadings to a closed system
All pathways end in the lakes.
Understand the total loading of pollutants to each lake from all pathways. (first
recognized for phosphorus, as reflected in the Great Lakes Water Quality
Lakewide Management Plans called for in the Agreement can provide the
'schedule of load reductions of Critical Pollutants that would result in meeting
Control of Pollutants
High degree of control for point sources (direct discharges)
nonpoint sources hard to control because of diffuse nature, episodic release and
lack of institutional arrangements to support their control.
Nonpoint sources less suited to regulatory control.
public education, pollution prevention and voluntary actions are very important
for non point sources
Pollution prevention focuses on eliminating pollutants before they are produced
(changing production processes, feedstock’s, environmentally friendly products)
Preventive ban the production/extraction and use of certain chemicals and
metals; also prevent the direct discharge of chemicals into waterways.
Bioaccumulation and Biomagnification
Phytoplankton must collect nutrients necessary for plant growth from a
relatively large volume of water. Also collect certain human-made chemicals,
such as some persistent pesticides
Biologically accumulate (bioaccumulate) become concentrated at levels that are
much higher in the living cells than in the open water.
especially true for persistent chemicals - substances that do not break down
readily in the environment - like DDT and PCBs Small fish and zooplankton eat phytoplankton toxic chemicals accumulated by
phytoplankton are concentrated in animals that eat them
Increasing concentration through the food chain is known as biomagnification.
Top predators (lake trout, salmon, gulls) may accumulate concentrations high
enough to cause serious deformities or death
Concentration in the fatty tissues of top predators can be millions of times
higher than concentration in water
Eggs of aquatic birds often have some of the highest concentrations of toxic
Habitat and biodiversity
Nearly all of the existing forests have been cut at least once and the forest and
prairie soils suited to agriculture have been plowed or intensively grazed
Construction of dams and urbanization
Streams have been changed by physical disturbance, sedimentation, changes in
runoff rates due to changing land use, and increases in temperature caused by
removal of vegetation.
70 - 80 % of the original wetlands of Southern Ontario have been lost since
U.S. loss of wetlands 42% in Minnesota – 92% in Ohio
Loss of these lands problems for hydrological processes and water quality
because of the natural storage and cleansing functions of wetlands
Biodiversity # of species and the genetic diversity within species
Some species have become extinct as a result of changes in basin and many
threatened with extinction or loss of important genetic diversity
Lack of diversity within a species can also increase the vulnerability of the
population to catastrophic loss caused by disease or a major change in
Introduction of exotic, i.e., non-native, species of plants and animals.
Sea lamprey, carp, smelt, alewife, Pacific salmon and zebra mussels impacts.
Invading plants such as purple loosestrife and European buckthorn displace
Changes in terrestrial plant communities have been caused by suppression of fire
Invasion by exotic species has resulted in loss of biodiversity
Fish Consumption Advisories
1971 the first sport fish advisory was issued in the Great Lakes for people
consuming fish caught from the lakes
Issued on a regular basis to limit exposure and protect health
Strictest for women of childbearing age, pregnant women and pre-teen children Trimming visible fat and broiling rather than frying so that fat drips away will
reduce a large proportion of these contaminants in fish
Pollution prevention, protecting and restoring habitat, protecting biodiversity,
understanding the ecosystem and cleaning up old pollution problems
The process of change in which the exploitation of resources, the direction of
investments, the orientation of technological development and institutional
change are made consistent with future as well as present needs World
Commission on Environment and Development (Bruntland Commission)
Test of whether sustainable development has been achieved will be whether this
integrity has been restored or maintained
Integrity of an ecosystem ecosystems contain mechanisms that create both
stability and resiliency within them capacity of the system to remain intact, to
self-regulate and evolve
Geographic Areas of Concern
Areas of Concern are those geographic areas where beneficial use of water or
biota is adversely affected or where environmental criteria are exceeded to the
extent that use impairment exists or is likely to exist
Most IJC Areas of Concern are near the mouths of tributaries where cities and
industries are located.
Several of the areas are along the connecting channels between the lakes.
Long-term accumulation of contaminants deposited from local point and
nonpoint sources and from upstream sources
Nearly all the Areas of Concern have contaminated sediments.
Continued remedial and preventive action is necessary.
Remedial Action Plans (RAPs) to guide specific rehabilitation activities in all 42
areas (one Area of Concern - Collingwood Harbour - has been cleaned up)
Major Diversion Proposals
Large-scale diversion of water from water-rich regions of North America to
water-poor areas experiencing growth in population and industry
Interbasin transfer of Great Lakes water or Canada's Arctic fresh waters
southward to the western U.S.
1960s, a California engineering firm proposed a 'North American Water and
Power Alliance' (NAWAPA). The plan included diversion of water from Alaska and
northwestern Canada through a major valley in the Canadian Rockies (Rocky
Mountain Trench) for distribution as far as Mexico
Colorado proposal called for a canal or a pipeline to carry water from the Great
Lakes to rapidly growing economies in the Southwest. Both ideas were opposed
by all Great Lakes states and the Province of Ontario. Great Recycling and Northern Development (GRAND) Canal concept was revived
in l985 after being proposed in the l950s. The plan calls for turning James Bay
into a freshwater lake using a dam to prevent mixing with saltwater from
Hudson Bay. Fresh water would then be pumped over the Arctic divide and
transferred into the Great Lakes. Great Lakes water would in turn be diverted for
sale to western states. Development would require an estimated $l00 billion