<pubnumber>905B95001</pubnumber>
<title>Great Lakes an Environmental Atlas and Resource Book</title>
<pages>51</pages>
<pubyear>1995</pubyear>
<provider>NEPIS</provider>
<access>online</access>
<origin>PDF</origin>
<author>Canada. Environment Canada. ; United States. Environmental Protection Agency. Great Lakes National Program Office.</author>
<publisher>Great Lakes National Program Office, U.S. Environmental Protection Agency ;</publisher>
<subject>Water quality management--Great Lakes Region ; Natural resources--Great Lakes Region--Maps ; Land use--Great Lakes Region--Maps ; Great Lakes Region--Maps ; Great Lakes Region--Economic conditions--Maps</subject>
<abstract></abstract>
<operator>mja</operator>
<scandate>07/23/09</scandate>
<type>single page tiff</type>
<keyword></keyword>
EPA 905-B-95-001
THE GREAT LAKES
An Environmental Atlas
and Resource Book
r
image:
US EPA-AWBERC LIBRARY
30701 100444352
United States Environmental
Protection Agency
and
Government of Canada
ISBN 0-662-23441-3
Copies may be obtained from:
Great Lakes National Program Office
U.S. Environmental Protection Agency
77 West Jackson Blvd
Chicago, Illinois
60604 U.S.A.
EPA 905-B-95-001
Public Inquiries
Environment Canada, Ontario Region
4905 Dufferin Street
Downsview, Ontario
M3H 5T4 Canada
Cat. No. EN40-349/1995E
image:
Jointly produced by:
Toronto, Ontario
and
Great Lakes National Program Office
Chicago, Illinois
lird Edition
1995
image:
Acknowledgemen ts
The third edition of this atlas consists
of a revision and update of the original
document produced by Environment Canada,
United States Environmental Protection
Agency and authored by Lee Botts and Bruce
Krushelnicki. Six maps originally produced
by Brock University Cartography Group have
been retained in this revised edition. The
high quality cartography was recognized by
the British Cartographical Society and
received an award for excellence in
cartography and design in 1988.
Contributors to the third edition:
Principal editors:
Kent Fuller,
United States Environmental
Protection Agency,
Great Lakes National Program Office
Harvey Shear, Ph.D.,
Jennifer Wittig,
Environment Canada,
Ontario Region
The following people and agencies
have given valuable assistance to this project
by providing information, reviewing or con-
tributing to text, or by making helpful
comments for this third edition:
W. Adam, Great Lakes Commission,
Ann Arbor, Michigan
S. Barrett, Waterfront Regeneration
Trust, Toronto, Ontario
M. Evans, Environment Canada, Ontario
Region, Toronto, Ontario
C. Flaherty, United States
Environmental Protection Agency, Great
Lakes National Program Office, Chicago,
Illinois
P. Fong, Statistics Canada, Ottawa,
Ontario
A. Gilman, Great Lakes Health Effects
Program, Environmental Health
Directorate, Health Canada, Ottawa, Ontario
V. Glumac, Environmental Conservation
Branch, Environment Canada, Ontario
Region, Burlington, Ontario
J. Hartig, Wayne State University,
Detroit, Michigan
J. Mortimer, Great Lakes Health Effects
Program, Environmental Health Directorate,
Health Canada, Ottawa, Ontario
N. Patterson, Environment Canada,
Ontario Region, Toronto, Ontario
N. Stadler-Salt, Environment Canada,
Ontario Region, Burlington, Ontario
S. Thorp, Great Lakes Commission,
Ann Arbor, Michigan
J. Tilt, Ontario Ministry of Natural
Resources, Toronto, Ontario
M. Webb, Environment Canada, Ontario
Region, Toronto, Ontario
Principal authors and contributors to the
first and second editions:
R. Beltran, United States Environmental
Protection Agency, Great Lakes National
Program Office, Chicago, Illinois
L. Botts, Northwestern University,
Evanston, Illinois (Author)
P. Brown, L. Gasparotto, A. Hughes,
Brock University Cartography,
St. Catharines, Ontario
T. Clarke, Environment Canada, Ontario
Region, Burlington, Ontario
D. Cowell, Environment Canada,
Ontario Region, Toronto, Ontario
K. Fuller, United States Environmental
Protection Agency, Great Lakes National
Program Office, Chicago, Illinois
B. Krushelnicki, Institute of Urban and
Environmental Studies, Brock University,
St. Catharines, Ontario (Author)
Additional contributors:
J. Anderson, Department of Geography,
Concordia University, Montreal, Quebec
A. Ballert, Great Lakes Commission,
Ann Arbor, Michigan
A. Beeton, Great Lakes Environmental
Research Laboratory, NOAA, Ann Arbor,
Michigan
F. Berkes, Institute of Urban and
Environmental Studies, Brock University,
St. Catharines, Ontario
M. Brooksbank, Environment Canada,
Ontario Region, Toronto, Ontario
V. Cairns, Department of Fisheries and
Oceans, Burlington, Ontario
D. Coleman, Inland Waters and Lands
Directorate, Environment Canada, Ontario
Region, Burlington, Ontario
M. Dickman, Department of Biological
Sciences, Brock University, St. Catharines,
Ontario
G. Francis, Department of Environment
and Resource Studies, University of
Waterloo, Waterloo, Ontario
A. Hamilton, International Joint
Commission, Ottawa, Ontario
C. Herdendorf, Ohio Sea Grant, Put-In
Bay, Ohio
S. Leppard, Land Use Research
Associates, Toronto, Ontario
J. Lloydd, Environment Canada,
Ontario Region, Burlington, Ontario
J. Middleton, Institute of Urban and
Environmental Studies, Brock University,
St. Catharines, Ontario
M. Neilson, Environmental
Conservation Branch, Environment Canada,
Ontario Region, Burlington, Ontario
G. Rodgers, National Water Research
Institute, Environment Canada, Burlington,
Ontario
R. Shipley, Welland Canal Preservation
Association, St. Catharines, Ontario
W. Sonzogni, Wisconsin State
Laboratory of Hygiene, University of
Wisconsin, Madison, Wisconsin
J. Vallentyne, Department of Fisheries
and Oceans, Burlington, Ontario
image:
Contents
PAGE
Chapter One
INTRODUCTION: THE GREAT LAKES 3
Physical Characteristics of the System 3
Settlement 4
Exploitation 4
Industrialization 4
The Evolution of Great Lakes Management 4
Toxic Contaminants 5
Understanding the Great Lakes from an
Ecosystem Perspective 5
Chapter Two
NATURAL PROCESSES IN THE GREAT LAKES 7
Geology 7
Climate 9
Climate Change and the Great Lakes 9
The Hydrologic Cycle 9
Surface Runoff 11
Wetlands 11
Groundwater 11
Lake Levels 12
Lake Processes: Stratification and Turnover 13
Living Resources 14
Chapter Three
PEOPLE AND THE GREAT LAKES 17
Native People 17
Early Settlement by Europeans 17
Development of the Lakes 17
Agriculture 18
Logging and Forestry 18
Canals, Shipping and Transportation 20
Commercial Fisheries 20
Sport Fishery 22
Recreation 22
Urbanization and Industrial Growth 24
Levels, Diversions and Consumptive Use Studies 27
Chapter Four
THE GREAT LAKES TODAY - CONCERNS 29
Pathogens 29
PAGE
Eutrophication and Oxygen Depletion 29
Toxic Contaminants 30
Pathways of Pollution 31
Loadings to a Closed System 32
Control of Pollutants 33
Bioaccumulation and Biomagnification 33
Habitat and Biodiversity 35
Exotic Species 35
Fish Consumption Advisories 35
Sustainable Development 35
Geographic Areas of Concern 37
Major Diversion Proposals 37
Other Basin Concerns 37
Chapter Five
JOINT MANAGEMENT OF THE GREAT LAKES 39
The Boundary Waters Treaty of 1909 39
Local Public Involvement 39
National Institutional Arrangements for
Great Lakes Management 40
The Great Lakes Fishery Commission 40
The Great Lakes Water Quality Agreement-1972 40
The International Joint Commission 41
The Great Lakes Water Quality Agreement-1978 41
The Great Lakes Water Quality Agreement-1987 42
An Ecosystem Approach to Management 42
Chapter Six
NEW DIRECTIONS FOR THE GREAT LAKES
COMMUNITY 43
Cooperation 43
Research 43
The Future of the Great Lakes 43
People in the Ecosystem 43
GLOSSARY 44
CONVERSION TABLE (Metric to Imperial Values) 44
REFERENCES AND SUGGESTIONS FOR
FURTHER READING 45
SOURCES FOR MAPS AND PHOTOGRAPHIC CREDITS 46
PAGE
PRODUCTION 46
LIST OF MAPS
Relief, Drainage and Urban Areas 2
Geology and Mineral Resources 6
Winter Temperatures and Ice Conditions, Frost Free
Period and Air Masses, Summer Temperatures,
Precipitation and Snowbelt Areas 8
The Great Lakes Water System 10
Coronelli's 1688 Map of Western New France:
An Early Depiction of the Great Lakes 16
Land Use, Fisheries and Erosion 19
Waterborne Commerce 21
Recreation 23
Employment and Industrial Structure 25
Roads and Airports, Pipelines, Railroads,
Electrical Power Lines and Generating Stations 26
Distribution of Population 28
State of the Lakes 34
Ecoregions, Wetlands and Drainage Basins 38
LIST OF DIAGRAMS
Geologic Time Chart 7
Hydrograph of Great Lakes Water Levels 12
WindSet-Up 13
Lake Stratification and Turnover 13
The Food Web 15
Population Growth in the Great Lakes Basin 18
Sediment Resuspension 31
Sources and Pathways of Pollution 32
Bioaccumulation of Persistent Chemicals 33
Geographic Areas of Concern: Impaired Uses 36
LIST OF GREAT LAKES FACTSHEETS
FACTSHEET NO.
1 Physical Features and Population 4
2 Land and Shoreline Uses 18
3a Water Withdrawals 27
3b Water Consumed 27
image:
RELIEF, DRAINAGE
AND URBAN AREAS
THE
GREAT
LAKES
BASIN
o*
v^
ELEVATIONS
ABOVE
SEA LEVEL
Peninsula
Over 500 m
300 - 500 m
200 - 300 m
100 • 200 m
0- 100 m
~ -TORONTO _J.-i.- '
• I --J>»
..^ Rochester
- Mgin Fills •Morth'TmwJnl|2
• ^ ,^—s--x
<p -^Buffalo
Porl CtBFX
£V
Liiiini
-
DEPTHS
BELOW
LAKE LEVEL
Inn
Racine Nintn
0-100 m
100 - 200 m
Over 200 m
Metres Feet
100 328
200 656
300 994
5OO 1640
SCALE 1:5000000
50 100 150 200 250 kilometres
25 50 75 100 125 150 175 miles
Fimck Urliveisily CaiTOgidphy
image:
The Great Lakes - Superior, Michigan,
Huron, Erie and Ontario - are an important
part of the physical and cultural heritage of
North America. Spanning more than 1,200
kilometres (750 miles) from west to east, these
vast inland freshwater seas have provided
water for consumption, transportation, power,
recreation and a host of other uses.
The water of the lakes and the many
resources of the Great Lakes basin have
played a major role in the history and
development of the United States and
Canada. For the early European explorers
and settlers, the lakes and their tributaries
were the avenues for penetrating the
continent, extracting valued resources
and carrying local products abroad.
Now the Great Lakes basin is home
to more than one-tenth of the population
of the United States and one-quarter of the
population of Canada. Some of the world's
largest concentrations of industrial capacity
are located in the Great Lakes region. Nearly
25 percent of the total Canadian agricultural
production and 7 percent of the American
production are located in the basin. The
United States considers the Great Lakes a
fourth seacoast, and the Great Lakes region
is a dominant factor in the Canadian industrial
economy.
PHYSICAL
CHARACTERISTICS
OF THE SYSTEM
The magnitude of the Great Lakes
water system is difficult to appreciate, even
for those who live within the basin. The lakes
contain about 23,000 km3 (5,500 cu. mi.) of
water, covering a total area of 244,000 km2
(94,000 sq. mi.) The Great Lakes are the
largest system of fresh, surface water on
earth, containing roughly 18 percent of the
world supply. Only the polar ice caps contain
more fresh water.
In spite of their large size, the Great
Lakes are sensitive to the effects of a wide
range of pollutants. The sources of pollution
include the runoff of soils and farm chemicals
from agricultural lands, the waste from cities,
discharges from industrial areas and leachate
from disposal sites. The large surface area of
the lakes also makes them vulnerable to
direct atmospheric pollutants that fall with
rain or snow and as dust on the lake surface.
ONE
INTRODUCTION:
the
GREAT LAKES
northern region of the Great Lakes is sparsely populated and is characterized by coniferous forest and rocky
shorelines. Above, the western shore of Georgian Bay in the Bruce Peninsula National Park.
Outflows from the Great Lakes are
relatively small (less than 1 percent per year)
in comparison with the total volume of water.
Pollutants that enter the lakes - whether by
direct discharge along the shores, through
tributaries, from land use or from the
atmosphere - are retained in the system and
become more concentrated with time. Also,
pollutants remain in the system because of
resuspension (or mixing back into the water)
of sediment and cycling through biological
food chains.
Because of the large size of the
watershed, physical characteristics such as
climate, soils and topography vary across the
basin. To the north, the climate is cold and
the terrain is dominated by a granite bedrock
called the Canadian (or Laurentian) Shield
consisting of Precambrian rocks under a
generally thin layer of acidic soils. Conifers
dominate the northern forests.
In the southern areas of the basin, the
climate is much warmer. The soils are deeper
with layers or mixtures of clays, silts, sands,
gravels and boulders deposited as glacial
drift or as glacial lake and river sediments.
The lands are usually fertile and can be
readily drained for agriculture. The original
deciduous forests have given way to
agriculture and sprawling urban development.
Although part of a single system, each
lake is different. In volume, Lake Superior is
the largest. It is also the deepest and coldest
of the five. Superior could contain all the
other Great Lakes and three more Lake Eries.
Because of its size. Superior has a retention
time of 191 years. Retention time is a measure
based on the volume of water in the lake and
the mean rate of outflow. Most of the Superior
basin is forested, with little agriculture
because of a cool climate and poor soils.
The forests and sparse population result
in relatively few pollutants entering Lake
Superior, except through airborne transport.
Lake Michigan, the second largest,
is the only Great Lake entirely within the
United States. The northern part is in the
colder, less developed upper Great Lakes
region. It is sparsely populated, except for
the Fox River Valley, which drains into Green
Bay. This bay has one of the most productive
Great Lakes fisheries but receives the wastes
from the world's largest concentration of
pulp and paper mills. The more temperate
southern basin of Lake Michigan is among
the most urbanized areas in the Great Lakes
system. It contains the Milwaukee and
Chicago metropolitan areas. This region is
home to about 8 million people or about
one-fifth of the total population of the Great
Lakes basin.
Lake Huron, which includes Georgian
Bay, is the third largest of the lakes by
volume. Many Canadians and Americans
own cottages on the shallow, sandy beaches
of Huron and along the rocky shores of
Georgian Bay. The Saginaw River basin is
intensively farmed and contains the Flint
and Saginaw-Bay City metropolitan areas.
Saginaw Bay, like Green Bay, contains a very
productive fishery.
Lake Erie is the smallest of the lakes
in volume and is exposed to the greatest
effects from urbanization and agriculture.
Because of the fertile soils surrounding the
lake, the area is intensively farmed. The lake
receives runoff from the agricultural area of
southwestern Ontario and parts of Ohio,
Indiana and Michigan. Seventeen metropoli-
tan areas with populations over 50,000 are
located within the Lake Erie basin. Although
the area of the lake is about 26,000 km2
(10,000 square miles), the average depth is
only about 19 metres (62 feet). It is the
shallowest of the five lakes and therefore
warms rapidly in the spring and summer, and
image:
1 Introduction : The Great Lakes
frequently freezes over in winter. It also has
the shortest retention time of the lakes, 2.6
years. The western basin, comprising about
one-fifth of the lake, is very shallow with an
average depth of 7.4 metres (24 feet) and a
maximum depth of 19 metres (62 feet).
Lake Ontario, although slightly smaller
in area, is much deeper than its upstream
neighbor, Lake Erie, with an average depth of
86 metres (283 feet) and a retention time of
about 6 years. Major urban industrial centers,
such as Hamilton and Toronto, are located on
its shore. The U.S. shore is less urbanized and
is not intensively farmed, except for a narrow
band along the lake.
I SETTLEMENT
The modern history of the Great Lakes
region, from discovery and settlement by
European immigrants to the present day,
can be viewed not only as a progression of
intensifying use of a vast natural resource,
but also as a process of learning about the
Great Lakes ecosystem. At first it was a
matter of making use of the natural
resources of the basin while avoiding its
dangers. Not until much later, when the
watershed was more intensively settled and
exploited, was it learned that abuse of the
waters and the basin could result in great
damage to the entire system.
I EXPLOITATION
The first Europeans found a relatively
stable ecosystem, which had evolved during the
10,000 years since the retreat of the last glacier;
a system that was only moderately disturbed
by the hunting and agricultural activities of the
native peoples. The first European arrivals had
a modest impact on the system, limited to the
exploitation of some fur-bearing animals.
However, the following waves of immigrants
logged, farmed and fished commercially in
the region, bringing about profound ecological
changes. The mature forests were clear-cut
from the watersheds, soil was laid bare by
the plow, and the undisturbed fish popula-
tions were harvested indiscriminately by an
awesome new predator- humans with nets.
As settlement and exploitation
intensified, portions of the system were
drastically changed. Logging removed
Great Lakes Factsheet No. 1
Physical Features And Population
Elevation3
Length
Breadth
Average Depth3
Maximum Depth3
Volume3
Superior
(feet)** 600
(metres) 183
(miles)* 350
(kilometres) 563
(miles)* 160
(kilometres) 257
(feet)** 483
(metres) 147
(feet)* 1,332
(metres) 406
(cu. miles)* 2,900
(km3) 12,100
Michigan
577
176
307
494
118
190
279
85
925
282
1,180
4,920
Huron
577
176
206
332
183
245
195
59
750
229
850
3,540
Erie
569
173
241
388
57
92
62
19
210
64
116
484
Ontario
243
74
193
311
53
85
283
86
802
244
393
1,640
Totals
5,439
22,684
I AREA
Water (sq. mi.)* 31,700 22,300
(km2) 82,100 57,800
Land Drainage Areab(sq. mi.)* 49,300 45,600
(km2) 127,700 118,000
Total (sq. mi.)* 81,000 67,900
(km2) 209,800 175,800
Shoreline Length0 (miles)* 2,726 1,638
(kilometres) 4,385 2,633
Retention Time (years)** 191 99
Population: U.S. (1990)' 425,548 10,057,026
Canada (1991) 181,573
Totals 607,121 10,057,026
Outlet St. Marys Straits of
Mackinac
23,000
59,600
51,700
134,100
74,700
193,700
3,827
6,157
22
1,502,687
1,191,467
2,694,154
St. Clair
9,910
25,700
30,140
78,000
40,050
103,700
871
1,402
2.6
10,017,530
1,664,639
11,682,169
Niagara River
River Welland Canal
7,340
18,960
24,720
64,030
32,060
82,990
712
1,146
6
2,704,284
5,446,611
8,150,895
St. Lawrence
River
94,250
244,160
201,460
521,830
295,710
765,990
10,210d
17,017"
24,707,075
8,484,290
33,191,365
River
Notes:
a Measured at Low Water Datum.
b Land Drainage Area for Lake Huron includes St. Marys River.
Lake Erie includes the St. Clair-Detroit system.
Lake Ontario includes the Niagara River.
c Including islands.
d These totals are greaterthan the sum of the shoreline length for the lakes because they include
the connecting channels (excluding the St. Lawrence River).
Sources: * Coordinating Committee on Great Lakes Basic Hydraulic and Hydrologic Data,
COORDINATED GREAT LAKES PHYSICAL DATA. May, 1992
**EXTENSION BULLETINS E-1866-70, Michigan Sea Grant College Program, Cooperative
Extension Service, Michigan State University, E. Lansing, Michigan, 1985
T 1990-1991 population census data were collected on different watershed boundaries and are not directly
comparable to previous years.
protective shade from streams and left them
blocked with debris. Sawmills left streams
and embayments clogged with sawdust.
When the land was plowed for farming the
exposed soils washed away more readily,
burying valuable stream and river mouth
habitats. Exploitive fishing began to reduce
the seemingly endless abundance of fish
stocks, and whole populations of fish began
to disappear.
I INDUSTRIALIZATION
Industrialization followed close behind
agrarian settlement, and the virtually untreated
wastes of early industrialization degraded one
river after another. The growing urbanization
that accompanied industrial development
added to the degradation of water quality,
creating nuisance conditions such as bacterial
contamination, putrescence and floating
debris in rivers and nearshore areas. In
some situations, the resulting contaminated
drinking water and polluted beaches
contributed to fatal human epidemics of
waterborne diseases such as typhoid fever.
Nonetheless, the problems were perceived
as being local in nature.
As industrialization progressed and as
agriculture intensified after the turn of the 20th
century, new chemical substances came into
use, such as PCBs (polychlorinated biphenyls)
in the 1920s and DDT (dichloro-diphenyl-
trichloroethane) in the 1940s. Non-organic
fertilizers were used to enrich the already
fertile soils to enhance production. The
combination of synthetic fertilizers, existing
sources of nutrient-rich organic pollutants,
such as untreated human wastes from cities,
and phosphate detergents caused an acceler-
ation of biological production (eutrophiction)
in the lakes. In the 1950s, Lake Erie showed
the first evidence of lake-wide eutrophic
imbalance with massive algal blooms and
the depletion of oxygen.
I THE EVOLUTION OF
GREAT LAKES
MANAGEMENT
In the late 1960s, growing public
concern about the deterioration of water
quality in the Great Lakes stimulated new
investment in pollution research, especially
the problems of eutrophication and DDT.
Governments responded to the concern
by controlling and regulating pollutant
discharges and assisting with the construc-
tion of municipal sewage treatment works.
This concern was formalized in the first
Great Lakes Water Quality Agreement
between Canada and the U.S. in 1972.
Major reductions were made in
pollutant discharges in the 1970s. The results
were visible. Nuisance conditions occurred
image:
IJ
/ -"':: * "~s= ~°'~'~ 5~~ ~L- i-~ v
less frequently as floating debris and oil slicks
began to disappear. Dissolved oxygen levels
improved, eliminating odor problems. Many
beaches reopened as a result of improved
sewage control, and algal mats disappeared
as nutrient levels declined. The initiatives of
the 1970s showed that improvements could
be made and provided several important
lessons beyond the cleanup of localized
nuisance conditions.
First, the problem of algal growth in
the lakes caused by accelerated eutrophica-
tion required a lake-wide approach to
measure the amount of the critical nutrient,
phosphorus, entering and leaving each lake
from all sources and outlets. This approach
of calculating a 'mass balance' of the
substance was then combined with other
research and mathematical modeling to set
target loading limits for phosphorus entering
the lake (or portions of the lake). The target
load is the amount of phosphorus that will
not cause excessive algal growth (i.e., an
amount that could safely be assimilated
by the ecosystem).
Other major lessons learned about
the system resulted from research on toxic
substances, initially the pesticide DDT. Toxic
contaminants include persistent organic
chemicals and metals. These substances
enter the lakes directly from discharges of
sewage and industrial effluents and indirectly
from waste sites, diffuse land runoff and
atmospheric deposition. As a result of
increased research, sampling and surveillance,
toxic substances have been found to be a
system-wide problem.
IC
Toxic contaminants pose a threat not
only to aquatic and wildlife species, but to
human health as well, since humans are at
the top of many food chains. Some toxic
substances biologically accumulate or are
magnified as they move through the food
chain. Consequently, top predators such as
lake trout and fish-eating birds - cormorants,
ospreys and herring gulls - can receive
extremely high exposures to these contami-
nants. Concentrations of toxic substances can
be millions of times higher in these species
than in water. As a result, the potential for
human exposure to these contaminants is far
greater from consumption of contaminated
fish and wildlife than from drinking water.
Aquatic and wildlife species have been
intensively studied, and adverse effects such
as cross-bills and egg-shell thinning in birds,
and tumors in fish are well documented.
There is less certainty about the risk to
human health of long-term exposure to low
levels of toxic pollutants in the lakes, but
there is no disagreement that the risk to
human health will increase if toxic contami-
nants continue to accumulate in the Great
Lakes ecosystem. Long-term, low-level
exposures are of concern because of subtle
effects that toxic contaminants may have on
reproduction, the immune system and
development in children. Relationships
between environmental contaminants and
diseases such as cancer are also of concern.
The ecosystem approach, together with
an increased emphasis on toxic substances,
was given formal recognition in the second
Great Lakes Water Quality Agreement, signed
in 1978. In 1987, management aspects of
the ecosystem approach were further defined
in revisions to the Agreement, calling for
management plans to restore fourteen
beneficial uses. The beneficial uses to be
restored include unimpaired use of the
ecosystem by ail living components,
including humans.
The Agreement called for Remedial
Action Plans (RAPs) to be prepared for
geographic Areas of Concern (AOCs) where
local use impairments exist. It also called for
Lakewide Management Plans to be prepared
for critical pollutants that affect whole lakes
or large portions of them. The purpose of
these management plans is to clearly identify
the key steps needed to restore and protect
the lakes.
To measure restoration of ecosystem
recovery, the 1987 Agreement revisions
added a call for ecosystem objectives and
indicators to complement the chemical
objectives already provided in the Agreement.
These biological measures of ecosystem
integrity provide an important element of
the ecosystem approach and are being
developed as part of the process for
developing lake-wide management plans.
Ecosystem indicators have already been
adopted for Lake Superior. These indicators
are organisms (such as bird or fish
populations) that tell us whether the
ecosystem is healthy and whether these
populations are stable and self-reproducing.
The concepts of mass balance, system-
wide contamination and bioaccumulation
in the food chain have become essential
components in understanding the lakes from
an ecosystem perspective. For example,
the mass balance approach to phosphorus
control has been used to formulate target
pollutant loadings for the lower lakes.
Over 33 million people who live in the
Great Lakes basin and their governments
face an immense challenge for the future of
the basin. The wise management needed to
maintain the use of Great Lakes resources
requires greater public awareness, the forging
of political will to protect the lakes, and
creative government action and cooperation.
It will not be easy.
The Great Lakes are surrounded by two
sovereign nations, a Canadian province, eight
American states and thousands of local,
regional and special-purpose governing
bodies with jurisdiction for management
of some aspect of the basin or the lakes.
Cooperation is essential because problems
such as water consumption, diversions, lake
levels and shoreline management do not
respect political boundaries.
With this in mind, public consultations
that include residents, private organizations,
industry and government are considered to
be an essential part of the decision-making
process for managing the resources of the
Great Lakes ecosystem. Residents of the
basin have been empowered to participate
in the problem-solving process, promote
healthy sustainable environments and
reduce their personal exposure to Great
Lakes contaminants.
Humans are part of and depend on
the natural ecosystem of the Great Lakes,
but may be damaging the capacity of the
system to renew and sustain itself and the
life within it. Protection of the lakes for future
use requires a greater understanding of
how past problems developed, as well as
continued remedial action to prevent further
damage.
image:
STAGES IN THE EVOLUTION
OF THE GREAT LAKES
SCALE 1: 20 OOO OOO
NOTE:
The maps on left are
"snapshots" of a
continuously changing
situation during the
retreat of the Wisconsin
icesheet. They should
not be viewed as a simple
sequence, since many
intermediate stages are
omitted The letters BP
denote before present.
GEOLOGY AND
MINERAL RESOURCES
SCALE 1: 7 500 000
100 200 300 kilometres
b
200 miles
p Ice
"_ Ice Front
Advancing Ice
Fresli Water
| | Salt Water
Present Coastline
GLACIAL
DEPOSITS
PRINCIPAL MINERAL AREAS
Copper & Zinc
Gold& Silver
345 - 290 BP
SCALE
1: 20 000 OOO
Stratified Drift
Silt and Clay (glacial lake deposits)
Sand and Gravel (outwash, alluvial
and ice contact deposits)
Unstratified Drift
Till (ground and end moraines)
Bedrock areas where the glacial cover is
absent (e.g. parts of Canadian Shield)
are not distinguished.
Uranium
Iron Ore
Nickel
GEOLOGICAL PERIODS
Pennsylvaman \ Carboniferous
| | Mississippian '
| Devonian
| | Silurian
| Ordovician
I Cambrian
[ | Precambrian
400 - 345 BP
440-400 BP
500-440 BP
570-500 BP
4500-570 BP
The extraction of minerals such as sand, gravel and
limestone .s widespread and not mappabJe at this scale.
Other minerals, such as salt and gypsum, are omitted
to preserve clarity.
Figures denote age in millions of years
before present (BP)
GENERALIZED CROSS-SECTION
Door
Peninsula
Lake
Michigan
i
Bay I
Lower Michigan
Bruce
Peninsula
B
Brock Uimcr-sitv Ct
image:
The foundation for the present Great
Lakes basin was set about 3 billion years
ago, during the Precambrian Era. This era
occupies about five-sixths of all geological
time and was a period of great volcanic
activity and tremendous stresses, which
formed great mountain systems. Early
sedimentary and volcanic rocks were folded
and heated into complex structures. These
were later eroded and, today, appear as the
gently rolling hills and stnay mountain
remnants of the Canadian Shield, which forms
the northern and northwestern portions of
the Great Lakes basin. Granitic rocks of
the shield extend southward beneath the
Paleozoic, sedimentary rocks where they
form the 'basement' structure of the southern
and eastern portions of the basin.
With the coming of the Paleozoic Era,
most of central North America was flooded
again and again by marine seas, which
were inhabited by a multitude of life forms,
including corals, crinoids, brachiopods and
mollusks. The seas deposited lime silts, clays,
sand and salts, which eventually consolidated
into limestone, shales, sandstone, halite and
gypsum.
During the Pleistocene Epoch, the
continental glaciers repeatedly advanced over
the Great Lakes region from the north. The
first glacier began to advance more than a
million years ago. As they inched forward, the
glaciers, up to 2,000 metres (6,500 feet) thick,
scoured the surface of the earth, leveled hills,
and altered forever the previous ecosystem.
Valleys created by the river systems of the
previous era were deepened and enlarged
to form the basins for the Great Lakes.
Thousands of years later, the climate began
to warm, melting and slowly shrinking the
glacier. This was followed by an interglacial
period during which vegetation and wildlife
returned. The whole cycle was repeated
several times.
Sand, silt, clay and boulders deposited
by the glaciers occur in various mixtures and
forms. These deposits are collectively referred
to as 'glacial drift' and include features such
as moraines, which are linear mounds of
poorly sorted material or 'till1, flat till plains,
till drumlins, and eskers formed of well-
sorted sands and gravels deposited from
rneltwater. Areas having substantial deposits
of well-sorted sands and gravels (eskers,
kames and outwash) are usually significant
groundwater storage and transmission areas
called 'aquifers'. These also serve as excellent
sources of sand and gravel for commercial
extraction.
As the glacier retreated, large volumes
of meltwater occurred along the front of the
ice. Because the land was greatly depressed
at this time from the weight of the glacier,
large glacial lakes formed. These lakes were
much larger than the present Great Lakes.
Their legacy can still be seen in the form of
beach ridges, eroded bluffs and flat plains
located hundreds of metres above present
lake levels. Glacial lake plains known as
lacustrine plains' occur around Saginaw Bay
and west and north of Lake Erie.
As the glacier receded, the land began
to rise. This uplift (at times relatively rapid)
and the shifting ice fronts caused dramatic
changes in the depth, size and drainage
patterns of the glacial lakes. Drainage from
the lakes occurred variously through the
Illinois River Valley (towards the Mississippi
River), the Hudson River Valley, the Kawartha
Lakes (Trent River) and the Ottawa River
Valley before entering their present outlet
through the St. Lawrence River Valley.
Although the uplift has slowed considerably,
it is still occurring in the northern portion of
the basin. This, along with changing long-
term weather patterns, suggests that the
lakes are not static and will continue to
evolve.
Pleistocene Epoch
Cenozoic Era—i»_
Mesozoic Era T
Paleozoic Era
-$L
Precarnbrian Era
Present
63 Million Years
230 Million Years
600 Million Years
Approximate Time
Since Start Of
Period
± 3 Billion Years
GEOLOGIC TIME CHART. The Great Lakes basin
is a relatively young ecosystem having formed
during the last 10,000 years. Its foundation was
laid through many millions of years and several
geologic eras. This chart gives a relative idea of
the agaofthaeras.
image:
-20
-20
WINTER TEMPERATURES
AND ICE CONDITIONS
MEAN DAILY
AIR TEMPERATURE
FOR JANUARY IN °C
0 • -10
-2.5 1-12.5
-5 1-15
-7.5 I -17.5
-10 I -20
' -22.5
-12.5
-7.5
MAXIMUM ICE
COVER IN TENTHS
10 [solid ice)
7- 9
1 • 6
0 (open water)
FROST FREE PERIOD
AND AIR MASSES
MEAN ANNUAL FROST
FREE PERIOD IN DAYS
1220 i 140
200
180
160
140
120
100
80
60
40
AIR MASS
FREQUENCY
Summer
1 5-20%
30-40%
40%
SUMMER
TEMPERATURES
MEAN DAILY
AIR TEMPERATURE
FOR JULY IN °C
22.5
MEAN WATER
TEMPERATURE
FOR JULY IN "C
Selected isotherms
only are shown for
each lake
PRECIPITATION AND
SNOWBELT AREAS
700
MEAN ANNUAL
PRECIPITATION IN mm
1300 ^_ 1000
1200 900
1100 { 800
1000 700
' 600
SCALE 1:10000000
50 100 150 200 250 mi
MAJOR
SNOWBELTS
WITH RANGE
OF MEAN ANNUAL
SNOWFALL IN
200-
300
Snowbelts are
defined as areas
of local snowfall
maxima
cm in
150 59.1
200 78,7
250 98,6
300 118.1
350 1378
1200
1100
900
1000
mm in mm in mm in
1300 51.2 1000 39.4 700 27.6
90O 354 6OO 23.6
800 31.5
1200 472
1100 43.3
brock University Cartography
image:
The weather in the Great Lakes basin
is affected by three factors: air masses from
other regions, the location of the basin
within a large continental landmass, and
the moderating influence of the lakes
themselves. The prevailing movement of
air is from the west. The characteristically
changeable weather of the region is the
result of alternating flows of warm, humid
air from the Gulf of Mexico and cold, dry
air from the Arctic,
In summer, the northern region around
Lake Superior generally receives cool, dry air
masses from the Canadian northwest. In the
south, tropical air masses originating in the
Gulf of Mexico are most influential. As the
Gulf air crosses the lakes, the bottom layers
remain cool while the top layers are warmed.
Occasionally, the upper layer traps the cooler
air below, which in turn traps moisture and
airborne pollutants, and prevents them
from rising and dispersing. This is called a
temperature inversion and can result in dank,
humid days in areas in the midst of the basin,
such as Michigan and Southern Ontario, and
can also cause smog in low-lying industrial
areas.
V,--, '«-_> ' . 'L"/rft-j.JJ ffiSii £ _;,---> '- '-" ---;"L. .. ;s "i,
Increased summer sunshine warms the
surface layer of water in the lakes, making it
lighter than the colder water below. In the fall
and winter months, release of the heat stored
in the lakes moderates the climate near the
shores of the lakes. Parts of Southern Ontario,
Michigan and western New York enjoy milder
winters than similar mid-continental areas at
lower latitudes.
In the autumn, the rapid movement and
occasional clash of warm and cold air masses
through the region produce strong winds,
Air temperatures begin to drop gradually
and less sunlight, combined with increased
cloudiness, signal more storms and precipita-
tion. Late autumn storms are often the most
perilous for navigation and shipping on the
lakes.
In winter, the Great Lakes region is
affected by two major air masses. Arctic air
from the northwest is very cold and dry when
it enters the basin, but is warmed and picks
up moisture traveling over the comparatively
warmer lakes. When it reaches the land, the
moisture condenses as snow, creating heavy
snowfalls on the lee side of the lakes in areas
frequently referred to as snowbelts. For part
of the winter, the region is affected by Pacific
air masses that have lost much of their
moisture crossing the western mountains.
Less frequently, air masses enter the basin
from the southwest, bringing in moisture
from the Gulf of Mexico. This air is slightly
warmer and more humid. During the winter,
the temperature of the lakes continues to
drop. Ice frequently covers Lake Erie but
seldom fully covers the other lakes.
Spring in the Great Lakes region, like
autumn, is characterized by variable weather.
Alternating air masses move through rapidly,
resulting in frequent cloud cover and thun-
derstorms. By early spring, the warmer air
and increased sunshine begin to melt the
snow and lake ice, starting again the thermal
layering of the lakes. The lakes are slower
to warm than the land and tend to keep
adjacent land areas cool, thus prolonging
cool conditions sometimes well into April.
Most years, this delays the leafing and
blossoming of plants, protecting tender
plants, such as fruit trees, from late frosts.
This extended state of dormancy allows
plants from somewhat warmer climates to
survive in the western shadow of the lakes.
It is also the reason for the presence of
vineyards in those areas.
CLIMATE CHANGE
MA various times throughout its history,
the Great Lakes basin has been covered by
thick glaciers and tropical forests, but these
changes occurred before humans occupied
the basin. Present-day concern about the
atmosphere is premised on the belief that
society at large, through its means of
production and modes of daily activity,
especially by ever increasing carbon dioxide
emissions, may be modifying the climate at
a rate unprecedented in history.
The very prevalent 'greenhouse effect'
is actually a natural phenomenon. It is a
process by which water vapor and carbon
dioxide in the atmosphere absorb heat given
off by the earth and radiate it back to the
surface. Consequently the earth remains
warm and habitable (16°C average world
temperature rather than -18°C without the
greenhouse effect). However, humans have
increased the carbon dioxide present in the
atmosphere since the industrial revolution
from 280 parts per million to the present 350
ppm, and some predict that the concentration
will reach twice its pre-industrial levels by
the middle of the next century.
Climatologists, using the General
Circulation Model (GCM), have been able to
determine the manner in which the increase
of carbon dioxide emissions will affect the
climate in the Great Lakes basin. Several of
these models exist and show that at twice the
carbon dioxide level, the climate of the basin
will be warmer by 2-4°C and slightly damper
than at present. For example, Toronto's
climate would resemble the present climate
of southern Ohio. Warmer climates mean
increased evaporation from the lake surfaces
and evapotranspiration from the land surface
of the basin. This in turn will augment the
percentage of precipitation that is returned to
the atmosphere. Studies have shown that the
resulting net basin supply, the amount of
water contributed by each lake basin to the
overall hydrologic system, will be decreased
by 23 to 50 percent. The resulting decreases
in average lake levels will be from half a metre
to two metres, depending on the GCM used.
Large declines in lake levels would
create large-scale economic concern for
the commercial users of the water system.
Shipping companies and hydroelectric power
companies would suffer economic repercus-
sions, and harbors and mannas would be
adversely affected. While the precision of :
such projections remains uncertain, the ;
possibility of their accuracy embraces ;
important long-term implications for the ;
Great Lakes.
The potential effects of climate change
on human health in the Great Lakes region
are also of concern, and researchers can only
speculate as to what might occur. For
example, weather disturbances, drought, and
changes in temperature and growing season
could affect crops and food production in the
basin. Changes in air pollution patterns as a
result of climate change could affect
respiratory health, causing asthma, and new
disease vectors and agents could migrate
into the region.
Water is a renewable resource. It is
continually replenished in ecosystems
through the hydrologic cycle. Water
evaporates in contact with dry air, forming
water vapor. The vapor can remain as a gas,
contributing to the humidity of the
atmosphere; or it can condense and form
water droplets, which, if they remain in the
air, form fog and clouds. In the Great Lakes
basin, much of the moisture in the region
evaporates from the surface of the lakes.
Other sources of moisture include the surface
of small lakes and tributaries, moisture on
the land mass and water released by plants.
Global movements of air also carry moisture
into the basin, especially from the tropics.
Moisture-bearing air masses move
through the basin and deposit their moisture
as rain, snow, hail or sleet. Some of this pre-
cipitation returns to the atmosphere and
some falls on the surfaces of the Great Lakes
to become part of the vast quantity of stored
fresh water once again. Precipitation that
falls on the land returns to the lakes as
surface runoff or infiltrates the soil and
becomes groundwater.
Whether it becomes surface runoff or
groundwater depends upon a number of
factors. Sandy soils, gravels and some rock
types contribute to groundwater flows,
whereas clays and impermeable rocks
contribute to surface runoff. Water falling
on sloped areas tends to run off rapidly,
while water falling on flat areas tends to
image:
d s a n
THE
GREAT LAKES
WAI !R SYS1 !M
1.4 2.1 1.4
(50) (74) (51)
Groundwater flow
0.9 0.5 0.4
5.8 (34) (19) (14)
(20S)
Niagara
St. Clair & s.3
Detroit Rivers (187)
Figures beside arrows represent
(low in thousands ol cubic metres
per second
Figures in brackets are in thousands
of cubic feel per second
All values are very approximate
Flow arrows are diagrammatic and
ate not always drawn in sine!
proportion lo the values they
represent
Continuously moving
weather systems.
Flow through
connecting channels.
Flow through
artificial diversions.
1. Runoff to lake.
2. Precipitation to lake
3. Evaporation from lake.
image:
: ~ ?f:° "--'"• r "-"--•>'
be absorbed or stored on the surface.
Vegetation also tends to decrease surface
runoff; root systems hold moisture-laden
soil readily, and water remains on plants.
Surface runoff is a major factor in the
character of the Great Lakes basin. Rain
falling on exposed soil tilled for agriculture or
cleared for construction accelerates erosion
and the transport of soil particles and
pollutants into tributaries. Suspended soil
particles in water are deposited as sediment
in the lakes and often collect near the mouths
of tributaries and connecting channels. Much
of the sediment deposited in nearshore areas
is resuspended and carried farther into the
lake during storms. The finest particles (clays
and silts) may remain in suspension long
enough to reach the mid-lake areas.
Before settlement of the basin, streams
typically ran clear year-round because natural
vegetation prevented soil loss. Clearing of the
original forest for agriculture and logging has
resulted in both more erosion and runoff into
the streams and lakes. This accelerated runoff
aggravates flooding problems.
Wetlands are areas where the water table occurs above or near the land surface for at least
part of the year. When open water is present, it must be less than two metres deep (seven
feet), and stagnant or slow moving. The presence of excessive amounts of water in wetland
regions has given rise to hydric soils, as well as encouraged the predominance of water
tolerant (hydrophytic) plants and similar biological activity.
Four basic types of wetland are encountered in the Great Lakes basin: swamps, marshes,
bogs and fens. Swamps are areas where trees and shrubs live on wet, organically rich
mineral soils that are flooded for part or all of the year. Marshes develop in shallow standing
water such as ponds and protected bays. Aquatic plants (such as species of rushes) form
thick stands, which are rooted in sediments or become floating mats where the water is
deeper. Swamps and marshes occur most frequently in the southern and eastern portions of
the basin.
Bogs form in shallow stagnant water. The most characteristic plant species are the
sphagnum mosses, which tolerate conditions that are too acidic for most other organisms.
Dead sphagnum decomposes very slowly, accumulating in mats that may eventually become
many metres thick and form a dome well above the original surface of the water. It is this
material that is excavated and sold as peat moss. Peat also accumulates in fens. Fens
develop in shallow, slowly moving water. They are less acidic than bogs and are usually fed
by groundwater. Fens are dominated by sedges and grasses, but may include shrubs and stunted trees. Fens and bogs are commonly referred to as
'peatlands' and occur most frequently in the cooler northern and northwestern portions of the Great Lakes basin.
Wetlands serve important roles ecologically, economically and socially to the overall health and maintenance of the Great Lakes ecosystem. They provide
habitats for many kinds of plants and animals, some of which are found nowhere else. For ducks, geese and other migratory birds, wetlands are the most
important part of the migratory cycle, providing food, resting places and seasonal habitats.
Economically, wetlands play an essential role in sustaining a productive fishery. At least 32 of
the 36 species of Great Lakes fish studied depend on coastal wetlands for their successful
reproduction. In addition to providing a desirable habitat for aquatic life, wetlands prevent
damage from erosion and flooding, as well as controlling point and nonpoint source pollution.
Coastal wetlands along the Great Lakes include some sites that are recognized internationally
for their outstanding biological significance. Examples included the Long Point complex and
Point Pelee on the north shore of Lake Erie and the National Wildlife Area on Lake St. Clair.
Long Point also was designated a UNESCO Biosphere Reserve. Wetlands of the lower Great
Lakes region have also been identified as a priority of the Eastern Habitat Joint Venture of
the North American Waterfowl Management Plan, an international agreement between
governments and non-government organizations (NGOs) to conserve highly significant
wetlands.
Although wetlands are a fundamentally important element of the Great Lakes ecosystem and
are of obvious merit, their numbers continue to decline at an alarming rate. Over two-thirds of
the Great Lakes wetlands have already been lost and many of those remaining are threatened
by development, drainage or pollution.
©roundwater is important to the Great
Lakes ecosystem because it provides a
reservoir for storing water and slowly replen-
ishing the lakes in the form of base flow in
the tributaries. It is also a source of drinking
water for many communities in the Great
Lakes basin. Shallow groundwater also
provides moisture to plants.
As water passes through subsurface
areas, some substances are filtered out, but
some materials in the soils become dissolved
or suspended in the water. Salts and minerals
in the soil and bedrock are the source of what
is referred to as 'hard' water, a common
feature of well water in the lower Great
Lakes basin.
Groundwater can also pick up materials
of human origin that have been buried in
dumps and landfill sites. Groundwater conta-
mination problems can occur in both urban-
industrial and agricultural areas. Protection
and inspection of groundwater is essential to
protect the quality of the entire water supply
consumed by basin populations, because the
underground movement of water is believed
to be a major pathway for the transport of
pollution to the Great Lakes. Groundwater
may discharge directly to the lakes or
indirectly as base flow to the tributaries.
11
image:
The Great Lakes are part of the global
hydrologic system. Prevailing westerly winds
continuously carry moisture into the basin in
air masses from other parts of the continent.
At the same time, the basin loses moisture
in departing air masses by evaporation and
transpiration, and through the outflow of the
St. Lawrence River. Over time, the quantity
lost equals what is gained, but lake levels can
vary substantially over short-term, seasonal
and long-term periods.
Day-to-day changes are caused by winds
that push water on shore. This is called 'wind
set-up' and is usually associated with a major
lake storm, which may fast for hours or days.
Another extreme form of oscillation, known
as a 'seiche', occurs with rapid changes in
winds and barometric pressure.
Annual or seasonal variations in water
levels are based mainly on changes in pre-
cipitation and runoff to the Great Lakes,
Generally, the lowest levels occur in winter
when much of the precipitation is locked up
in ice and snow on Sand, and dry winter air
masses pass over the lakes enhancing
evaporation. Levels are'highest in summer
after the spring thaw when runoff increases.
The irregular long-term cycles
correspond to long-term trends in precipita-
tion and temperature, the causes of which
have yet to be adequately explained. Highest
levels occur during periods of abundant
precipitation and lower temperatures that
decrease evaporation. During periods of
high lake levels, storms cause considerable
flooding and shoreline erosion, which often
result in property damage. Much of the
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1 GREAT LAKES HYDROGRAPH. The Hydrograph for the Great Lak®$ shows the variations in water levels and the relationship of precipitation to water levels.
image:
damage is attributable to intensive shore
development, which alters protective dunes
and wetlands, removes stabilizing vegetation,
and generally reduces the ability of the
shoreline to withstand the damaging effects
of wind and waves.
The International Joint Commission,
the binational agency established under the
Boundary Waters Treaty of 1909 between
Canada and the U.S., has the responsibility
for regulation of flows on the St. Marys and
the St. Lawrence Rivers. These channels
have been altered by enlargement and
placement of control works associated
with deep-draft shipping.
Agreements between the U.S.
and Canada govern the flow
through the control works on
these connecting channels.
The water from Lake
Michigan flows to Lake Huron
through the Straits of Mackinac.
These straits are deep and wide,
resulting in Lakes Michigan
and Huron standing at the
same elevation. There are no
artificial controls on the St.
Clair and Detroit Rivers that could change
the flow from the Michigan-Huron Lakes
system into Lake Erie. The outflow of Lake
Erie via the Niagara River is also uncon-
trolled, except for some diversion of water
through the Welland Canal. A large
percentage of the Niagara River flow is
diverted through hydroelectric power plants
at Niagara Falls, but this diversion has no
effect on lake levels.
Studies of possible further regulation
of flows and lake levels have concluded that
natural fluctuation is huge compared with
the influence of existing control works.
Further regulation by engineering systems
could not be justified in light of the cost and
other impacts. Just one inch (two and a half
centimetres) of water on the surface of Lakes
Michigan and Huron amounts to more than
36 billion cubic metres of water (about 1,260
billion cubic feet).
WIND SET-UP is a local rise in water caused by winds pushing water
to one side of a lake.
The Great Lakes are not simply large
containers of uniformly mixed water. They
are, in fact, highly dynamic systems with
complex processes and a variety of
subsystems that change seasonally and
on longer cycles.
The stratification or layering of water in
the lakes is 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). This causes
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
'hypolirnnion'. Surface and nearshore waters
are warmed by the sun, making them less
dense so that they form a surface layer
called the 'epilimnion'. As the summer pro-
gresses, temperature differences increase
between the layers. A thin middle layer, or
'thermocline', develops in which a rapid
transition in temperature occurs.
The warm epilimnion supports most
of the life in the lake. Algal production is
greatest near the surface where the sun
readily penetrates. The surface layer is also
rich in oxygen, which is mixed into the water
from the atmosphere. A second zone of
high productivity exists just above the
hypolirnnion, due to upward diffusion of
nutrients. The hypolirnnion is less productive
because it receives less sunlight In some
areas, such as the central basin of Lake Erie,
it may lack oxygen because of decomposition
of organic matter.
In late fall, surface waters cool, become
denser and descend, displacing deep waters
and causing a mixing or turnover of the
entire lake. In 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.
As temperatures and densities of deep and
shallow waters change with the warming of
spring, another turnover may occur. However,
in most cases the lakes remain mixed
throughout the winter.
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LAKE STRATIFICATION (LAYERING} AND TURNOVER. Heat from the sun and changing seasons cause water in large lakes to stratify or form layers. In winter, the ice cover stays
atO°C 132° F) and the water remains warmer below the ice than in the air above. Water is most dense at4°C(39"F). In the spring turnover, warmer water rises as the surface
heats up. In fall, surface waters cool, become dense rand descend as heat is lost from the surface. In summer, stratification is caused by a warming of surface waters, which
form a distinct layer called the epilimnion. This is separated from the cooler and denser waters of the hypolimnion by the thermocline, a layer of rapid temperature transition.
Turnover distributes oxygen annually throughout most of the lakes.
image:
- - : "'•>•'• •""
r v j. rf fjffjf
-~
Ms an ecosystem, the Great Lakes basin
is a unit of nature in which living organisms
and nonliving things interact adaptively.
An ecosystem is fueled by the sun, which
provides energy in the form of light and heat.
This energy warms the earth, the water and
the air, causing winds, currents, evaporation
and precipitation. The light energy of the sun
is essential for the photosynthesis of green
plants in water and on land. Plants grow
when essential nutrients such as phosphorus
and nitrogen are present with oxygen,
inorganic carbon and adequate water.
Plant material is consumed in the water
by zooplankton, which graze the waters for
algae, and on land by plant-eating animals
(herbivores). Next in the chain of energy
transfer through the ecosystem are organisms
that feed on other animals (carnivores) and
those that feed on both animals and plants
(omnivores). Together these levels of
consumption constitute the food chain, or
web, a system of energy transfers through
which an ecological community consisting of
a complex of species is sustained. The
population of each species is determined by
a system of checks and balances based on
factors such as the availability of food and
the presence of predators, including disease
organisms.
Every ecosystem also includes nume-
rous processes to break down accumulated
biomass (plants, animals and their wastes)
into the constituent materials and nutrients
from which they originated. Decomposition
involves micro-organisms that are essential
to the ecosystem because they recycle
matter that can be used again.
Stable ecosystems are sustained by the
interactions that cycle nutrients and energy
in a balance between available resources and
the life that depends on those resources. In
ecosystems, including the Great Lakes basin,
everything depends on everything else and
nothing is ever really wasted.
The ecosystem of the Great Lakes and
the life supported within it have continuously
altered with time. Through periods of climate
change and glaciation, species moved in and
out of the region; some perished and others
pioneered under changed circumstances.
None of the changes, however, has been as
rapid as that which occurred with the arrival
of European settlers.
When the first Europeans arrived in
the basin nearly 400 years ago, it was a lush,
thickly vegetated area. Vast timber stands,
consisting of oaks, maples and other hard-
woods dominated the southern areas. Only a
very few small vestiges of the original forest
remain today. Between the wooded areas
were rich grasslands with growth as high
as 2 or 3 metres (7 to 10 feet). In the north,
coniferous forests occupied the shallow,
sandy soils, interspersed by bogs and other
wetlands.
The forest and grasslands supported
a wide variety of life, such as moose in the
wetlands and coniferous woods, and deer in
the grasslands and brush forests of the south.
The many waterways and wetlands were
home to beaver and muskrat which, with
the fox, wolf and other fur-bearing species.
The layering and turnover of water
annually are important for water quality.
Turnover is the main way in which oxygen-
poor water in the deeper areas of the lakes
can be mixed with surface water containing
more dissolved oxygen. This prevents anoxia,
or complete oxygen depletion, of the lower
levels of most of the lakes. However, the
process of stratification during the summer
also tends to restrict dilution of pollutants
from effluents and land runoff.
During the spring warming period,
the rapidly warming nearshore waters are
inhibited from moving to the open lake by
a thermal bar, a sharp temperature gradient
that prevents mixing until the sun warms the
open lake surface waters or until the waters
are mixed by storms. Because the thermal
bar holds pollutants nearshore, they are
not dispersed to the open waters and can
become more concentrated within the
nearshore areas.
image:
inhabited the mature forest lands. These
were trapped and traded as commodities by
the native people and the Europeans.
Abundant bird populations thrived on the
various terrains, some migrating to the south
in winter, others making permanent homes in
the basin.
It is estimated that there were as many
as 180 species of fish indigenous to the
Great Lakes. Those inhabiting the nearshore
areas included smallmouth and largemouth
bass, muskellunge, northern pike and
channel catfish. In the open water were lake
herring, blue pike, lake whitefish, walleye,
sauger, freshwater drum, lake trout and
white bass. Because of the differences in the
characteristics of the lakes, the species
composition varied for each of the Great
Lakes. Warm, shallow Lake Erie was the
most productive, while deep Superior was
the least productive.
Changes in the species composition of
the Great Lakes basin in the last 200 years
have been the result of human activities.
Many native fish species have been lost by
overfishing, habitat destruction or the arrival
of exotic or non-indigenous species, such as
the lamprey and the alewife. Pollution,
especially in the form of nutrient loading and
toxic contaminants, has placed additional
stresses on fish populations. Other hurnan-
rnade stresses have altered reproductive
conditions and habitats, causing some
varieties to migrate or perish. Still other
effects on lake life result from damming,
canal building, altering or polluting
tributaries to the lakes in which spawning
takes place and where distinct ecosystems
once thrived and contributed to the larger
basin ecosystem.
The FOOD WEB is a simplified way of understanding the
process by which organisms in higher trophic levels gain
energy by consuming organisms at lower trophic levels.
All energy in an ecosystem originates with the sun. The
solar energy is transformed by green plants through a
process of photosynthesis into stored chemical energy.
This is consumed by plant-eating animals, which are in
turn consumed as food. Humans are part of the food web.
The concept of the food web explains how some
persistent contaminants accumulate in an ecosystem and
become biologically magnified (see biomagnification and
b/oaccumulation in Chapter Four}.
Snapping
Turtle
Salmon/Lake Trout
invertebrates
Mineral Nutrients
NOTE
This is a simplified representation of the
food web showing the main pathways.
Food [energy! moves in the direction of
the arrows. The driving force is sunlight
Depictions: of the various organisms are
noftoscate.
Bacteria and Fungi
Dead Animate and Plants
15
image:
LABRADOR
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BATHOS it ClIOXCASrETMON.
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PART IE OCCIDENTALE
^CANADAondcUNOUVELL
FRAN C E
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Coronelli's 1688 Map of Western New France. The first printed map
to show the Great Lakes in their entirety and the most accurate
general portrayal of the lakes and tributaries in the 17th century.
image:
The first inhabitants of the Great Lakes
basin arrived about 10,000 years ago. They
had crossed the land bridge from Asia or
perhaps had reached South America across
the vastness of the Pacific Ocean. Six
thousand years ago, descendants of the first
settlers were using copper from the south
shore of Lake Superior and had established
hunting and fishing communities throughout
the Great Lakes basin.
The population in the Great Lakes area
is estimated to have been between 60,000
and 117,000 in the 16th century, when
Europeans began their search for a passage
to the Orient through the Great Lakes. The
native people occupied widely scattered
villages and grew corn, squash, beans and
tobacco. They moved once or twice in a
generation, when the resources in an area
became exhausted.
ETTLEMENT
Hy the early 1600s, the French had
explored the forests around the St. Lawrence
Valley and had begun to exploit the area for
furs. The first area of the lakes to be visited
by Europeans was Georgian Bay, reached via
the Ottawa River and Lake Nipissing by the
explorer Samuel de Champlain or perhaps
Etienne Brule, one of Champlain's scouts, in
1615. To the south and east, the Dutch and
English began to settle on the eastern
seaboard of what is now the United States.
Although a confederacy of five Indian nations
confined European settlement to the area east
of the Appalachians, the French were able to
establish bases in the lower St. Lawrence
Valley. This enabled them to penetrate into
the heart of the continent via the Ottawa
River. In 1670, the French built the first of a
chain of Great Lakes forts to protect the fur
trade near the Mission of St. Ignace at the
Straits of Mackinac. In 1673, Fort Frontenac,
on the present site of Kingston, Ontario,
became the first fort on the lower lakes.
Through the 17th century precious furs
were transported to Hochelaga (Montreal)
on the Great Lakes routes, but no permanent
European settlements were maintained except
at Forts Frontenac, Michilimackinac and
Niagara. After Fort Oswego was established
on the south shore of Lake Ontario by the
THREE
and the
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British in 1727, settlement was encouraged
in the Mohawk and other valleys leading
toward the lakes. A showdown between
the British and the French for control of the
Great Lakes ended with the British capture
of Quebec in 1759.
The British maintained control of the
Great Lakes during the American Revolution
and, at the close of the conflict, the Great
Lakes became the boundary between the new
U.S. republic and what remained of British
North America. The British granted land to the
Loyalists who fled the former New England
colonies to Upper and Lower Canada, now
the southern regions of the provinces of
Ontario and Quebec, respectively. Between
1792 and 1800 the population of Upper
Canada increased from 20,000 to 60,000. The
new American government also moved to
develop the Great Lakes region with the
passage by Congress of the Ordinance
of 1787. This legislation covered everything
from land sale to provisions for statehood
for the Northwest Territory, the area between
the Great Lakes and the Ohio River west of
Pennsylvania.
The final military challenge for the
wealth of the Great Lakes region came with
the War of 1812. For the Americans, the
war was about the expansion into, and
development of, the area around the lakes.
For the British, it meant the defense of
its remaining imperial holdings in North
America. The war proved to be a short
one - only 2 years - but final. When the
shooting was over both the Americans and
the British claimed victory.
Canada had survived invasion and was
set on an inevitable course to nationhood.
The new American nation had failed to
conquer Upper Canada but gained needed
national confidence and prestige. Native
people, who had become involved in the war
in order to secure a homeland, did not share
in the victory. The winners in the War of 1812
were those who dreamed of settling the
Great Lakes region. The long-awaited
development of the area from a beautiful,
almost uninhabited wilderness into a home
and workplace for millions began in earnest.
Muring the next 150 years the develop-
ment of the Great Lakes basin proceeded with
haste. The battles for territory so common
during the era of empires and colonies gave
way to nation-building, city-building and
industrialization. The warriors of the previous
era gave way to, or themselves became, the
entrepreneurs, farmers and laborers who ran
the mills, tilled the soil and provided the skills
and services required for modern industrial
economies.
The development of the Great Lakes
region proceeded along several lines that
took advantage of the many resources within
the basin. The waterways became major
highways of trade and were exploited for
image:
15
Lake Michigan * •?">= ::;| SSS<S^:4
"Lake Ontario
Lake Huron
Lake Superior
WO 1310 1920 1930 M40 1950 tgsg 1970 1SSO 1590
Years " "
Population growth in the Great Lakes basin since
WOO.
their fish. The fertile land that had provided
the original wealth of furs and food yielded
lumber, then wheat, then other agricultural
products. Bulk goods such as iron ore and
coal were shipped through Great Lakes ports,
and manufacturing grew.
The promise of agricultural land was
the greatest attraction to the immigrants to
the Great Lakes region in the 19th century.
By the mid-1800s, most of the Great Lakes
region where farming was possible was
settled. The population had swelled tremen-
dously. There were about 400,000 people in
Michigan, 300,000 in Wisconsin and perhaps
half a million in Upper Canada.
Canals led to broader commodity export
opportunities, allowing farmers to expand
their operations beyond a subsistence level.
Wheat and corn were the first commodities
to be packed in barrels and shipped abroad.
Grist mills- one of the region's first industries
-were built on the tributaries flowing into
the lakes to process the grains for overseas
markets.
As populations grew, dairying and meat
production for local consumption began to
dominate agriculture in the Great Lakes basin.
Specialty crops, such as fruit, vegetables and
tobacco, grown for the burgeoning urban
population, claimed an increasingly important
share of the lands suitable for them.
The rapid, large-scale clearing of land
for agriculture brought rapid changes in
the ecosystem. Soils stripped of vegetation
washed away to the lakes; tributaries and
silty deltas clogged and altered the flow of
the rivers. Fish habitats and spawning areas
were destroyed. Greater surface runoff led to
increased seasonal fluctuation in water levels
and the creation of more flood-prone lands
along the waterway. Agricultural development
has also contributed to Great Lakes pollution,
chiefly in the form of eutrophication. Fertilizers
that reach waterways in soils and runoff
stimulate growth of algae and other water
plants. The plants die and decay, depleting
the oxygen in the water. Lack of oxygen leads
to fish kills, and the character of the ecosystem
changes as the original plants and animals
give way to more pollution-tolerant species.
Modern row crop monoculture relies
heavily on chemicals to control pests such as
insects, fungi and weeds. These chemicals
are usually synthetic organic substances and
they find their way to rivers and lakes to affect
plant and animal life, and threaten human
health. The problem was first recognized
with DDT, a very persistent chemical, which
tended to remain in the environment for a
long time and to bioaccumulate through the
food chain. It caused reproductive failures in
some species of birds. Since the use of DDT
was banned, some bird populations are now
recovering. Other, less persistent, chemicals
have replaced DDT and other problem
pesticides, but toxic contamination from agri-
cultural practices continues to be a concern.
DDT levels in fish are declining but, in spite
of being banned, some other pesticides,
such as dieldrin, continue to persist in fish
at relatively high levels.
The original logging operations in the
Great Lakes basin involved clearing the land
for agriculture and building houses and
barns for the settlers, Much of the wood
was simply burned. By the 1830s, however,
commercial logging began in Upper Canada.
A few years iater logging began in Michigan,
and operations in Minnesota and Wisconsin
soon followed.
Once again the lakes played a vital role.
Cutting was generally done in the winter
months by men from the farms. They traveled
up the rivers felling trees that were floated
down to the lakes during the spring thaw. The
logs were formed into huge rafts or loosely
gathered in booms to be towed by steam
tugs. This latter practice had to be stopped
because logs often escaped the boom and
seriously interfered with shipping. In time,
timber was carried in ships specially designed
for log transport.
The earliest loggers mainly harvested
white pine. In virgin stands these trees
reached 60 metres (200 feet) in height, and
a single tree could contain 10 cubic metres
(6,000 board feet) of lumber. It was Sight and
strong and much in demand for shipbuilding
and construction. Each year, loggers had to
move farther west and north in search of
white pine. The trees were hundreds of years
old and so were not soon replaced. When
the resource was exhausted, lumbermen had
to utilize other species. The hardwoods such
as maple, walnut and oak were cut to make
furniture, barrels and specialty products.
Paper-making from pulpwood developed
slowly. The first sulfite process paper mill
was built on the Welland Canal in the 1860s.
Paper production developed at Green Bay in
the U.S. and elsewhere in the Great Lakes
basin. Eventually Canada and the U.S.
became the world's leading producers of
pulp and paper products. Today much of this
production still occurs in the Great Lakes
area. The pulp and paper industry (along
with chloralkali production) contributed to
the mercury pollution problem on the Great
Lakes until the early 1970s, when mercury
was banned from use in the industry.
The logging industry was exploitive
during its early stages. Huge stands were lost
in fires, often because of poor management
of litter from logging operations. In Canada,
lumbering was largely done on crown lands
with a small tax charged per tree. In the
United States, cutting was done on private
land but when it was cleared, the owners
often stopped paying taxes and let the land
revert to public ownership. In both cases,
clear-cutting was the usual practice. Without
proper rehabilitation of the forest, soils were
readily eroded from barren landscapes and
lost to local streams, rivers and lakes. In some
areas of the Great Lakes basin, reforestation
has not been adequate and today, as a result,
the forests may be a diminishing resource.
Great Lakes
rQC"£so©©^ I\S©. 2
Land And
Superior Michigan Huron Erie Ontario
f BASIN LAND USE
Agricultural
Canada 0.5 21 80
U.S. 6.0 44 40 63
Total 3.0 44 27 67
Residential
Canada 0.1 1 4
U.S. 3.0 9 6 12
Total 1.0 9 2 10
Forest
Canada 98.7 75 15
U.S. 80.0 41 52 23
Total 91.0 41 68 21
ffifhaB1
USSie!
Canada 0.7 3 1
U.S. 11.0 6 2 2
Other 5.0 631
1 SHORELINE USE
Residents!!!
Canada , 34 39
U.S. ' 39 42 45
BecreatioEiaJ
Canada , 88
U.S. ' 24 4 13
Agricultural
Canada , 4 21
U.S. ' 20 15 14
Commercial
Canada , 35 10
U.S. ' 12 32 12
Other
Canada / 19 22
U.S. n/a 5 7 16
Source: BULLETINS E-1866-70,
Sea Grant College Program,
Cooperative Extension Service,
Michigan State University,
E. Lansing, Michigan, 1985.
n/a: not available
49
33
39
6
8
7
42
53
49
3
6
5
25
40
15
12
30
33
18
8
12
7
f <,"
image:
LAND USE,
FISHERIES &
EROSION
LAND USE
Intensive General Farming
Low-intensity Farming/Pasture
Coniferous Forest
Mixed-wood Forest
Deciduous Forest
Urban Areas
COMMERCIAL FISHERIES
u.s. catch
Species of fish caught
Canadian catch
1MB II
NOTE:
1. Each bar represents the
average catch over a five-
year period.
2. The species shown (or
each lake are those which
have been consistently
important since 1950.
They are not necessarily
those which yielded the
largest catch in any five-
year period.
Tonnes Tons
4000
8000
12000
16000
20000
24000
28000
4400
8825
13225
17625
22050
26450
30875
SHORELINE EROSION
Minimal
Moderate
Severe
Scale 1 : 6 000 000
100 200 300 kilometres
X
150 200 miles
• Yellow Perch
Smell
• Walleye
Alowils
- - - - Whitefisri
- - - LaKe Herring
Uke Trout
• Yellow Perch
1920 1MO I9U l«0
Lake Erie
1120 tWO
Lake Ontario
.
• Whitefisri
Lake Superior
i*si ISM IM inn
Lake Huron
im IMO IM im
Lake Michigan
Geomatics International Cartography
image:
donflict over the Great Lakes continued
after the War of 1812 in the form of
competition to improve transportation routes.
By 1825, the 586 km (364 mile) Erie Canal, a
waterway from Albany, New York, to Buffalo,
was carrying settlers west and freight east.
The cost of goods in the west fel! 90 percent
while the price of agricultural products
shipped through the lakes rose dramatically.
Settlement in the fertile expanses of Ohio
and Michigan became even more attractive.
The Canadians opened the Lachine Canal
at about the same time to bypass the worst
rapids on the St. Lawrence River. In 1829, the
Welland Canal joined Lakes Erie and Ontario,
bypassing Niagara Falls. Other canals linked
the Great Lakes to the Ohio and Mississippi
Rivers, and the Great Lakes became the hub
of transportation in eastern North America.
Railroads replaced the canals after mid-
century, making still-important transportation
links between the Great Lakes and both
seacoasts. In 1959, completion of the St.
Lawrence Seaway allowed modern ocean
vessels to enter the lakes, but shipping has
not expanded as much as expected because
of intense competition from other modes of
transportation such as trucking and railroads.
Today, the three main commodities
shipped on the Great Lakes are iron ore, coal
and grain. Transport of iron ore has declined
as some steel mills in the region have shut
down or reduced production, but steel-making
capacity in North America is likely to remain
concentrated in the Great Lakes region. Coal
moves both east and west within the lakes,
but coal export abroad has not expanded as
much as was anticipated during the rapid
rise of oil prices in the 1970s. As a result of
economic decline, the Great Lakes fleet of
over 300 vessels is being reduced through
the retirement of the older, smaller vessels.
I COMMERCIAL FISHERIES
Fish were important as food for the
region's native people, as well as for the first
European settlers. Commercial fishing began
about 1820 and expanded about 20 percent
per year. The largest Great Lakes fish
harvests were recorded in 1889 and 1899 at
some 67,000 tonnes (147 million pounds).
However, by the 1880s some preferred
species in Lake Erie had declined. Catches
increased with more efficient fishing
equipment but the golden days of the
commercial fishery were over by the late
1950s. Since then, average annual catches
have been around 50,000 tonnes (110 million
pounds). The value of the commercial fishery
has declined drastically because the more
valuable, larger fish have given way to small
and relatively low-value species. Over-
fishing, pollution, shoreline and stream
habitat destruction, and accidental and
deliberate introduction of exotic species such
as the sea lamprey all played a part in the
decline of the fishery.
Today, lake trout, sturgeon and lake
herring survive in vastly reduced numbers
and have been replaced by introduced
species such as smelt, alewife, splake,
and Pacific salmon. Populations of some
of the native species such as yellow perch,
walleye and white bass have made good
recovery. Lake trout, once the top predator
in the lakes, survives in sufficient numbers
to allow commercial fishing only in Lake
Superior, the only lake where substantial
natural reproduction still occurs. However,
even in Superior, hatchery-reared trout are
stocked annually to maintain the population.
In addition to the lake trout, the blue
pike of Lake Erie, and the Atlantic salmon of
Lake Ontario were top predators in the open
waters of the lakes and were major
components of the commercial fishery in
earlier times. Of the three, the blue pike and
Lake Ontario Atlantic salmon are believed to
be extinct. Currently, hatchery-reared coho
and Chinook salmon are the most plentiful
top predators in the open lakes except in the
western portion of Lake Erie, which is
dominated by walleye.
Only pockets remain of the once large
commercial fishery. The Canadian commercial
fishery in Lake Erie remains prosperous. In
1991, 750 Canadian fishermen harvested a
total of about 2,300 tonnes (50 million pounds)
with a landed value of about $59 million
(Canadian). For Canada, the Lake Erie fishery
represents nearly two-thirds of the total Great
Lakes harvest. All commercial fish caught in
Canada are inspected prior to market for
quality and compliance with federal
regulations.
In the United States, the commercial
fishery is based on lake whitefish, smelt,
bloater chubs and perch, and on alewife for
animal feed. Commercial fishing is limited by
a federal prohibition on the sale of fish
affected by toxic contaminants. Pressure to
limit commercial fishing in the U.S. is also
exerted by sport fishing groups anxious to
manage the fishery in their interests. In
addition, the trend in the U.S. is to reduce
the pressure on the fishery by restricting
commercial fishing to trapnets that harvest
species selectively, without killing species
preferred by recreational fishermen.
Commercial fishing is under continuing
pressure from several fronts. Toxic contami-
nants could cause the closure of additional
fisheries as the ability to measure the
presence of chemicals improves together
with the knowledge of their effects on
human health.
20
ID
image:
J
WATERBORNE
COMMERCE
I CARGO VOLUME BY PORT
IN TONNES, 1990
Ports under 2 500 000 tonnes
100 000 - 500 000 tonnes
500 000 - 2 500 000 tonnes
• Ports over 2 500 000 tonnes
40 000 000 tonnes
20 000 000 tonnes
10 000 000 tonnes
5 000 000 tonnes
2 500 000 tonnes
COMMODITY TYPES
Coal
Grains/Soybeans
Iron Ore
Cement
Chemicals
Coke
Electrical Products
Limestone
Metals and Metal Products
Petroleum Products
Other
I INTER-LAKE COMMODITY
FLOW IN TONNES, 1990
Upbound
Downbound
Great Lakes Profile 1a st. Marys R^
;, Straits of
Mackinac
St. Clair River
Lake St. Clair
Detroit River
Welland
Canal
173.5m
iMke
Erie 64 m
X
©
SI
we
live
St.
Lawrence
River
74.2m
Lake
Ontario
204m
NOTE: 1. The profile is taken along the long axes of Ihe lakes
2. The vertical exaggeration is 2000 times.
3. Lake surface elevations are given above sea level.
and maximum depths are below lake surface.
4. Inter-lake lock and nver syslems are numbered
to correspond to map.
Lake Superior
Michigan
TORONTO
HAMILTON; £. /coi«,,,,
Lrf
*2. ^ke Ontario
r /./ y^
ASHTABULA
INDIANA
HARBOR
Tons
1 100
110250
551 270
2 756 340
5512680
10 000 000 11 025 360
20 000 000 22 050 720
30 000 000 33 076 070
40000000 44101430
Tonnes
1 000
100000
500 000
2 500 000
5 000 000
LORAIN
CLEVELAND
Scale 1 : 6 000 000
100 200 300
50
100
150
kilometres
200 miles
Geomatics International Cartography
image:
: r'L B -Iff- -,'jlr T-l -» r' C f. -*S-fi brrZi •" I*1- 'r-tr "- .-" -
22
Several factors have contributed to
the success of the sport fisheries. The sea
lamprey, which almost destroyed the lake
trout population, is being successfully
controlled using chemical lampricides and
low-head barrier dams. Walleye populations
rebounded in Lake Erie owing to regulation
of the commercial fishery and improvements
in water quality. The population of alewife
exploded as lamprey destroyed native top
predators. The increase in alewife provided a
forage base for new predators such as coho
and chinook salmon, which were introduced
in the 1960s to fill the gap left by depleted
lake trout stocks, when lamprey populations
declined.
The sport fishery developed quickly as
Pacific salmon rapidly grew to large sizes
after they were introduced into Lake Michigan.
Charter fleets developed and a minor tourist
boom led to plans to develop a large fish
stocking program to fuel a new sport fishing
industry.
By 1980, the idea of stocking exotic fish
such as salmon to support the sport fishery
had spread to all the lakes and jurisdictions.
Ontario and Michigan also experimented
with the 'splake', a hybrid of the native lake
trout and brook (or speckled) trout. None of
these predators has been able to reproduce
very well, if at all, so the fishery has been
maintained by stocking year after year.
Ironically, the exception is the pink salmon,
a small species accidentally introduced into
Lake Superior in 1955. It has survived to
establish spawning populations and spread
through Lakes Michigan and Huron, where it
established serf-propagating populations by
the 1980s.
Since early in the industrial age, the
waterways, shorelines and woodlands of the
Great Lakes region have been attractions for
leisure time activities. Many of the utilitarian
activities that were so important in the early
settlement and industrial development
became recreational activities in later years.
For example, boating, fishing and canoeing
were once commercial activities, but are now
primarily leisure pursuits.
Recreation in the area became an
important economic and social activity with
the age of travel in the 19th century. A thriving
pleasure-boat industry based on the newly
constructed canals developed, bringing people
into the region in conjunction with rail and
road travel. Niagara Falls attracted travelers
from considerable distances and was one of
the first stimulants to the growth of a leisure-
related economy. Later, the reputation of the
lower lakes region as the frontier of a pristine
wilderness drew people seeking restful cures
and miracle waters to the many spas and
'clinics' that developed along the waterway.
In the 20th century, more people had
more free time. With industrial growth,
greater personal disposable income and
shorter work weeks, people of all walks of
life began to spend their leisure time beyond
the city limits. Governments on both sides
of the border acquired lands and began to
develop an extensive system of parks,
wilderness areas and conservation areas in
order to protect valuable local resources and
to serve the needs of the population for
recreation areas. Unfortunately, by the time
the need for publicly accessible recreation
lands had become apparent, much of the
land in the basin, including virtually all the
shoreline on the lower lakes, was in private
hands. Today, about 80 percent of the U.S.
shoreline and 20 percent of the Canadian
shore is privately owned and not accessible
by the public.
The recreation industry includes
production and sale of sports equipment
and boats, marinas, resorts, restaurants
and related service industries that cater to a
wide range of recreational activities. In some
areas of the basin, recreation and tourism
are becoming an increasingly important
component of the economy, in place of man-
ufacturing. The Great Lakes basin provides
a wide range of recreational opportunities,
ranging from pristine wilderness activities
in national parks such as !s!e Royale and
Pukaskwa to intensive urban waterfront
beaches in major urban areas.
The increasingly intensive recreational
development of the Great Lakes has had
mixed impacts. Some recreational activities
cause environmental damage. Extensive
development of cottage areas, summer home
sites, beaches and mannas has resulted in
loss of wetland, dune and forest areas.
Shoreline alteration by developers and
individual property owners has caused
changes in the shoreline erosion and
deposition process, often to the detriment of
important beach and wetland systems that
depend upon these processes. The
development of areas susceptible to flooding
and erosion has caused considerable public
reaction. There is pressure to manage lake
levels to prevent changes that are part of
natural weather patterns and processes.
Pollution from recreational sites and boats
has also caused water-quality degradation.
Recreational uses are a threat to the
quality of the Great Lakes ecosystem, but
also provide a basis for protecting quality by
attracting and involving people who recognize
that protection of the ecosystem is essential
to sustain the recreation that they value.
People who use the water for its fun and
beauty can become a potent force in the
protection of the ecosystem. Naturalists,
anglers and cottagers were among the first
to bring environmental issues to the attention
of the public and call for the cleanup of the
lakes in the 1950s and 1960s, when eutrophi-
cation threatened favored fishing, bathing
and wildlife sites. Today more people than
ever use and value the lakes for recreational
purposes.
Recent years have seen a major
resurgence in recreational fishing as the
walleye fisheries recover and the new salmon
fisheries develop. Lake Ontario now sports a
very important salmon and trout recreational
fishery. The water-quality recovery in Lake Erie
"<"j! •* l^ ^ifs"1^ f £c! I "€"? L?" ?K»~ " JV-L °" a EL a -I *• jT-""™-" _"~ J"? JT"" pf1
J.'C'T.""* -fcr-.V^".
image:
RECREATION
PROTECTED AREAS
| National Park
j State/Provincial Park
I National Forest
State Forest
National Lakeshore
National Wildlife Area
National Recreation Area
National Marine Park/
Underwater Preserve
Crown Land
I RECREATIONAL AREAS & ROUTES
Ski Area
Canoe
Route
Long-
distance
Trail
Canalized
Waterway
Heritage
River
Scenic
River
NOTE: 1. The canoe routes include portages.
2. Not all sections of the trails shown
are yet in existence.
Recreational Boating Facilities
Sparse
\
Moderate
Dense
I SPORT FISHING
1. Area of circles are proportional to the
number of angler days in 1991:
Lake Superior - 883 000
Lake Michigan - 5 090 000
Lake Huron - 2113 000
Lake Erie - 7 082 000
Lake Ontario - 2 394 000
2. The data measure sport fishing effort, and
are classified according to species sought
as opposed to species actually caught.
3. Significant species in the 'other' category
are C - Catfish and bullhead,
P - Panfish and S - Sheephead.
4. The 'other' category also includes those
cases where the angler has no preference
for the species caught.
Scale 1 : 6 000 000
100 200 300 kilometres
Zj
200 miles
*-~~, Georgian
Bay Islands
Bruce.*
Pcnimuli
\£« National
;
'•GREEN BAY *
f**S I '
•«
'Oft/0 li
Erie Trail
Species of Fish Sought (1991)
Other -.-^ Salmon and Steelhead
Lake Trout
and Other Trout
Walleye, Sauger, Pike,
Pickerel and Muskie
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Geomatics International Cartography
image:
has been complemented by record walleye
reproduction in recent years. In many areas,
Buffalo, Cleveland, Chicago and Toronto par-
ticularly, there have been urban renewal
movements with the lake front as a primary
focus. Developing public access to the water
is a key element of these renewal projects.
il
24
Nearly all the settlements that grew
into cities in the Great Lakes region were
established on the waterways that transported
people, raw materials and goods. The largest
urban areas developed at the mouths of
tributaries because of transportation advan-
tages and the apparently inexhaustible supply
of fresh water for domestic and industrial
use. Historically, the major industries in the
Great Lakes region have produced steel,
paper, chemicals, automobiles and other
manufactured goods.
A large part of the steel industry in
Canada and the United States is concentrated
in the Great Lakes because iron ore, coal and
limestone can be carried on the lakes from
mines and quarries to steel mills, in the
United States, ore is carried from mines near
Lake Superior to steel mills at the south end
of Lake Michigan and at Detroit, Cleveland,
and Lorain in the Lake Erie basin. In Canada,
ore from the upper lakes region is processed
in steel mills at Sault Ste. Marie, Hamilton
and Nanticoke.
Paper-making in the U.S. occurs
primarily on the upper lakes, with the largest
concentration of mills along the Fox River,
which feeds into Green Bay on Lake Michigan.
In Canada, mills are located along the
Welland Canal as well as along the upper
lakes. Chemical industries developed on both
sides of the Niagara River because of the
availability of cheap electricity. Other major
concentrations of chemical production are
located near Saginaw Bay in Lake Huron
and in Sarnia, Ontario, on the St. Clair River,
because of abundant salt deposits and
plentiful water.
All of these industrial activities produce
vast quantities of wastes. Initially the wastes
of urban-industrial centers did not appear to
pose serious problems. Throughout most of
the 19th century industrial wastes were
dumped into the waterways, diluted and
dispersed. Eventually, problems emerged
when municipal water supplies became cont-
aminated with urban-industrial effluent. The
threat to public health from disease organisms
prompted some cities to adopt practices that
seemed for the time to solve the problem.
In 1854, Chicago experienced a cholera
epidemic in which 5 percent of the population
perished, and in 1891, the rate of death due
to typhoid fever had reached a high of 124
per 100,000 population. To protect its drinking
water supply from sewage, Chicago reversed
the flow of the Chicago River away from
Lake Michigan. A diversion channel was dug
to carry sewage effluent away from Lake
Michigan into the Illinois and Mississippi River
system. In Hamilton, in the 1870s, water could
no longer be drawn from the harbor or from
local wells because of contamination. A
steam-powered water pump was installed
to draw deep water from Lake Ontario for
distribution throughout the city.
Many of the dangers of industrial
pollution to the Great Lakes and to human and
environmental health were not recognized
until recently, in part because their presence
and their effects are difficult to detect. In
recent years this has become especially
evident where aging industrial disposal sites
leak chemicals discarded many years ago into
the environment or where sediments conta-
minated by long-standing industrial activities
continue to contribute dangerous pollutants
to the waterways. Now the region must cope
with cleanup of the pollution from these past
activities at the same time that the industrial
base for the regional economy is struggling
to remain competitive.
Use of Great Lakes resources brought
wealth and well-being to the residents of
Great Lakes cities but the full price of the
concentration of industry and people is only
now being understood. The cleanup of the
Great Lakes region will require continuous
expenditure by, and cooperation among,
state, provincial and federal agencies, local
governments and industry. Through this
cooperation, combined with public involve-
ment, contaminant levels in the Great Lakes
ecosystem have declined dramatically since
the 1970s. Because many pollutants tend to
persist in the environment, levels must
continue to be reduced. Pollution-prevention
measures are being combined with cleanup
to deal with pollution in the Great Lakes.
-^ ^ r^n "™ "-, \,' >""'"" TV ">"\ , --"?-
" .:. ; .s.J * 1..^:"::..... \i.J.":. " - 'v
image:
EMPLOYMENT
& INDUSTRIAL
STRUCTURE
I POPULATION & EMPLOYMENT
1990 (USA) 1991 (CANADA)
Number of People
6000000
3000000
. 1 500 000
1 000 000
500 000
100000
Employment Breakdown
Outer Circle = Total Population (TP)
Inner Circle = Working Population (WP)
I INDUSTRIAL STRUCTURE,
1990 (USA) 1991 (CANADA)
Public Administration
and Defense
Community
Services
(neanh, education,
religion)
Personal
Services
(recreation,
repairs, hotels.
«c.}
Finance.
Insurance,
Real Estate
Primary Industry
(agriculture, (oreslry.
mining)
Construction
Manufacturing
Industry
Transportation and
Communications
Trade
(retail and
STATISTICAL AREAS
1. The data mapped are based on Census Metropolitan
Areas (CMAs) in Canada and Metropolitan
Statistical Areas (MSAs) in the United States,
shown as:
2. In several cases, contiguous CMAs and MSAs have
been combined to preserve clarity.
3. Note that certain MSAs extend beyond the watershed
boundary of the Great Lakes basin.
Scale 1 : 6 000 000
100 200 300 kilometres
ID
200 miles
22. Oshawa
TP:240 104
WP: 130225
1. Thunder Bay
TP:124 427
WP: 65 155
2. Duluth
TP: 239 971
WP: 110851
3. Appleton-Oshkosh-
Neenah, Green Bay,
Sheboygan
TP: 613 592
WP: 324 463
23. Hamilton
TP: 599 760
WP: 318 330
4. Milwaukee, Racine
TP:1 607185
WP: 873 809
5. Chicago,
Kenosha,
Lake County,
Gary-Hammond
TP: 7 319 099
WP: 3 788 047
6. Elkhart-Goshen, South
Bend-Mishawaka
TP: 403 250
WP:208 193
7. Benton Harbor,
Ka la ma 2 oo
^^ TP: 384 789
WP: 197365
17. Erie
TP: 275 572
WP: 132202
18. London
TP:381 522
WP: 208 915
8. Grand Rapids,
Muskegon
TP: 847 382
WP:434 055
11. Detroit-Ann Arbor
TP: 4 665 236
WP: 2 326 077
14. Fort Wayne
TP: 363 811
WP: 193730
19. Sudbury
TP: 157 619
WP: 80020
12. Windsor
TP: 262 421
WP: 130745
15. Lima
TP: 154340
WP: 74584
20. Kitchener
TP: 356421
WP: 198 065
9. Battle Creek, Jackson,
Lansing-East Lansing
TP: 718412
WP: 366 256
10. Flint, Saginaw-
Bay City-Midland
TP: 829 779
WP: 389 814
»-\
•
13. Toledo
TP:614 128
WP: 303 422
16. Cleveland, Akron,
Lorain-Elyria
TP: 2 759 823
WP: 1 687 067
21. Toronto
TP: 3 893 046
WP:2 195550
24. St. Catharines,
Niagara Falls
TP:343 258
WP: 186 390
25. Buffalo,
Niagara Falls
TP:1 189288
WP: 584 658
26. Rochester
TP:1 002410
WP: 519059
27. Syracuse
TP: 659 864
WP: 332 361
Geomatics International Cartography
image:
ROADS AND
AIRPORTS
PIPELINES
AIRPORTS
* Major
• Minor
Ontario
Ruktsttr
ROADS
Toll Road
Trans Canada
Highway
SCALE 1:10000 000
100 200 300 400 km
I • I
50 100 150 200 250 mi
- - Ferry Service
ELECTRICAL
POWER LINES AND
GENERATING
STATIONS
RAILROADS
POWER LINES
GENERATING
STATIONS
Passenger and
Freight Lines
Freight Line
- Ferry Service
Only stations with
a total capacity
exceeding 100 MW
are shown
Brock Unive/sity Carlography
image:
The responsibilities of the International Joint
Commission (IJC) for levels and flows of the Great
Lakes are separate from its responsibilities for
water quality. Water quality objectives are set
by the Great Lakes Water Quality Agreement,
but decisions about levels and flows are made
to comply with the terms of the 1909 Boundary
Waters Treaty.
Only limited controls of levels and flows are possible
and only for Lake Superior and Lake Ontario. The
flows are controlled by locks and dams on the
St. Marys River, at Niagara Falls and in the St.
Lawrence. Special boards of experts advise the 1JC
about meeting the terms of the treaty. Members of
the binational control boards are equally divided
between government agencies in both countries.
Until 1973, the IJC managed levels and flows for
navigation and hydropower production purposes.
Since then, the IJC has tried to balance these
interests with prevention of shore erosion.
The IJC has carried out several special studies on
levels issues in response to references, or requests,
from the governments. In I964, when water levels
were very low, the governments asked the IJC
whether it would be feasible to maintain the
waters of all the Great Lakes, including Michigan
and Huron, at a more constant level. After a 9-year
study, in I973, when water levels were very high,
the IJC advised the governments that the high
costs of an engineering system for further
regulation of Michigan and Huron could not be
justified by the benefits. The same conclusion was
reached for further regulation of Lake Erie in I983.
Two human activities, diversion and consumptive
use, have potential for affecting lake levels,
although they have had relatively little impact to
date. Diversion refers to transfer of water from one
watershed to another. Consumptive use refers to
water that is withdrawn for use and not returned.
Most consumptive use in the Great Lakes is
Superior Michigan
Canada
U.S. '
Total
*
#*
36
70
62
110
98
2,940
2,262
2,940
2,622
Huron
120
107
310
277
430
384
Erie Ontario TOTALS
190
170
.2,820
2,515
3,010
2,685
660
589
sao
339
1,040
927
1,010
902
6,520
5,455
7,530
6,716
Canada
U,S,
Total
Canada *
**
U.S. *
Total
860
767
410
366
1,270
1,133
1,360
1,213
1,060
945
2,420
2,158
1,900
1,694
9,110
8,126
11,010
9,820
2,760
2,462
530
473
3,290
2,935
6,880
6,136
20,760
18,518
27,640
24,652
9,650
8,608
9,650
8,608
Power Production
70 2,870 1,160 8,370 12,470
62 2,560 1,035 7,466 11,123
760 13,600 2,570 13,180 6,520 36,360
.678 12,131 2,292 11,757 5,816 32,674
.830 13,600 5,440 14,340 14,890 49,100
** 740 12,131 4,852 12,791 13,282 43,796
6RAND TOTALS
* 2,210 26,190 8,290 28,360 19,220 84,270
1,971 23,361 7,394 23,296 17,144 75,166
* Cubic feet per second
** Millions of cubic metres per year
Source: BULLETINS E-1866-70, Sea Grant College Program, Cooperative Extension Service,
Michigan State University, E. Lansing, Michigan, 1985. ;
caused by evaporation from power plant cooling
systems.
At present, water is diverted into the Great Lakes
system from the Hudson Bay watershed through
Long Lac and Lake Ogoki, and diverted out of the
Great Lakes and into the Mississippi watershed
at Chicago. These diversions are almost equally
balanced and have had little long-term effect on
levels of the lakes.
In 1982, the IJC reported on a study of the effects
of existing diversions into and out of the Great
Lakes system and on consumptive uses. Until this
study, consumptive use had not been considered
significant for the Great Lakes because the volume
of water in the system is so large. The study con-
cluded that climate and weather changes affect
levels of the lakes far more than existing human-
made diversions. However, the report concluded
that if consumptive uses of water continue to
increase at historical rates, outflows through the
St. Lawrence River could be reduced by as much
as 8 percent by around the year 2030.
As illustrated by the hydrograph shown in Chapter
two, lake levels vary from year to year and can be
expected to continue to do so. Following the period
of high lake levels in the 1980s, the IJC conducted
another study of levels and the feasibility of modify-
ing them through various means. In 1993, the study
concluded that the costs of major engineering
works to further regulate the levels and flows of
the Great Lakes and St. Lawrence River would
exceed the benefits provided and would have
negative environmental impacts. Instead, it
recommended comprehensive and coordinated
land-use and shoreline management programs
throughout the basin that would help reduce
vulnerability to flood and erosion damages.
Municipal
Canada *
U.S.
Total
#
K*
* •
*#
Canada *
*#
U.S. *
Total
Superior Michigan
10
9
10 190
9 169
20 ' 190
18 . - 169
20
18
60
53,
80
71
Power Production
Canada *
•*#.
U.S. *
Total *
0
0
10
9
10
9
785
880
785
240
214
240
214
Huron
20
152
190
170
70
62
~30
27
100
89
20
18
50
45
70
62
Erie Ontario TOTALS
30
27
280
257
210
189
80
71
1,500
1,338
1,580
1,409
10
9
190
169
200
178
100
89
70
62
170
152
100
89
40
36
140
125
60
54
120
108
180
174
160
143
720
649
780
270
240
2,510
2,239
2,780
2,479
81
610
545
700
673
1,310
1,168
360
321
1,990
1,776
490
451
4,260
3,814
GRAND TOTALS
110
98
* Cubic feet per second
** Millions of cubic metres per year
Source; BULLETINS E-1866-70, Sea Grant College Program, Cooperative Extension Service,
Michigan State University, E. Lansing, Michigan, 1985.
27
image:
image:
man has hammered the artifact called
. No living man will see again
the virgin pineries of the Lake states, or the
flatwoods of the coastal plain, or the giant
parts of the Great Lakes
ecosystem have been changed to better
suit the needs of humans, the unexpected
consequences of many of the changes have
only recently become apparent. Since about
1960, there has been an awakening to the
magnitude of these changes and the harsher
implications of some human activities. The
largest categories of impact are pollution,
habitat loss and exotic species.
Deterioration in water quality and
habitat began with modern settlement. At
first the impact was localized. 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. Waste-
treatment solutions were adopted to treat
biological pollutants that threatened the
immediate health of populations. In some
jurisdictions, regulations were passed to
prevent capricious dumping in the waterways.
Eventually, however, it took a major threat to
the whole Great Lakes basin to awaken
authorities to the fact that the entire Great
Lakes ecosystem was being damaged.
Historically, the primary reason for
water pollution control was prevention of
waterborne disease. Municipalities began
treating drinking water by adding chlorine,
as a disinfectant. This proved to be a simple
solution to a very serious public health
problem, throughout the water distribution
system. Chlorine is still used because it is
able to kill pathogens throughout the distrib-
ution system.
Humans can acquire bacterial, viral
and parasitic diseases through direct body
contact with contaminated water as well as
by drinking the water. Preventing disease
Modern, large-scale agriculture, with its reliance on
synthetic fertilizers and pesticides, is one of the main
nonpoint sources of pollution to the Great Lakes.
transmission of this kind usually means
closing affected beaches during the summer
when the water is warm and when bacteria
from human and animal feces reach higher
concentrations. This is usually attributed to
the common practice of combining storm
and sanitary sewers in urban areas. Although
this practice has been discontinued, existing
combined sewers contribute to contamina-
tion problems during periods of high rainfall
and urban runoff. At these times, sewage
collection and treatment systems cannot
handle the large volumes of combined
storm and sanitary flow. The result is that
untreated sewage, diluted by urban runoff,
is discharged directly into waterways.
Remedial action can be very costly if
the preferred solution is replacement of the
combined sewers in urban areas with separate
storm and sanitary sewers. However, alterna-
tive techniques such as combined sewer
overflow retention for later treatment can be
used, greatly reducing the problem at lower
costs than sewer separation. Beach closures
have become more infrequent with improved
treatment of sewage effluent.
Lakes can be characterized by their
biological productivity, that is, the amount
of living material supported within them,
primarily in the form of algae. The least
productive lakes are called 'oligotrophic';
those with intermediate productivity are
'mesotrophic'; and the most productive are
'eutrophic'. The variables that determine
productivity are temperature. Sight, depth
and volume, and the amount of nutrients
received from the environment.
Except in shallow bays and shoreline
marshes, the Great Lakes were 'oligotrophic'
before European settlement and industrial-
ization. Their size, depth and the climate kept
them continuously cool and clear. The lakes
received small amounts of fertilizers such as
phosphorus and nitrogen from decomposing
organic material in runoff from forested lands.
Small amounts of nitrogen and phosphorus
also came from the atmosphere.
These conditions have changed.
Temperatures of many tributaries have been
increased by removal of vegetative shade
cover and some by thermal pollution. But,
more importantly, the amount of nutrients
and organic material entering the lakes has
increased with intensified urbanization and
agriculture. Nutrient loading increased with
the advent of phosphate detergents and
inorganic fertilizers. Although controlled in
most jurisdictions bordering the Great Lakes,
phosphates in detergents continue to be a
problem where they are not regulated.
Increased nutrients in the lakes stimulate
the growth of green plants, including algae.
The amount of plant growth increases rapidly
in the same way that applying lawn fertilizers
(nitrogen, phosphorus and potassium) results
in rapid, green growth. In the aquatic system
the increased plant life eventually dies, settles
to the bottom and decomposes. During
decomposition, the organisms that break
down the plants use up oxygen dissolved in
the water near the bottom. With more growth
there is more material to be decomposed, and
more consumption of oxygen. Under normal
conditions, when nutrient loadings are low,
dissolved oxygen levels are maintained by
the diffusion of oxygen into water, mixing by
currents and wave action, and by the oxygen
production of photosynthesizing plants.
Depletion of oxygen through decompo-
sition of organic material is known as
biochemical oxygen demand (BOD), which
is generated from two different sources. In
tributaries and harbors it is often caused by
materials contained in the discharges from
treatment plants. The other principal source
is decaying algae. In large embayments and
open lake areas such as the central basin of
Lake Erie, algal BOD is the primary problem.
As the BOD load increases and as
oxygen levels drop, certain species of fish
can be killed and pollution-tolerant species
that require less oxygen, such as sludge
worms and carp, replace the original species.
Changes in species of algae, bottom-dwelling
organisms (or benthos) and fish are therefore
biological indicators of oxygen depletion.
29
image:
Turbidity in the water as well as an increase
in chlorophyll also accompany accelerated
algal growth and indicate increased eutrophi-
cation.
Lake Erie was the first of the Great Lakes
to demonstrate a serious problem of eutroph-
ication because it is the shallowest, warmest
and naturally most productive. Lake Erie also
experienced early and intense deveiopment
of its lands for agricultural and urban uses.
About one-third of the total Great Lakes basin
population lives within its drainage area and
surpasses all other lakes in the receipt of
effluent from sewage treatment plants.
Oxygen depletion in the shallow central
basin of Lake Erie was first reported in the late
1920s. Studies showed that the area of oxygen
depletion grew larger with time, although the
extent varied from year to year owing, at least
in part, to weather conditions. Eutrophication
was believed to be the primary cause.
Before controls could be developed, it was
necessary to determine which nutrients were
most important in causing eutrophication
in previously mesotrophic or oligotrophic
waters. By the late 1960s, the scientific
consensus was that phosphorus was the
key nutrient in the Great Lakes and that
controlling the input of phosphorus could
reduce eutrophication.
The central basin of Lake Erie is
especially susceptible to depletion of
oxygen in waters near the bottom because
it stratifies in summer, forming a relatively
thin layer of cool water, the hypolimnion,
which is isolated from oxygen-rich surface
waters. Oxygen is rapidly depleted from this
thin layer as a result of decomposition of
organic matter. When dissolved oxygen
levels reach zero, the waters are considered
to be anoxic. With anoxia, many chemical
processes change and previously oxidized
pollutants may be altered to forms that are
more readily available for uptake by the
water. By contrast, the western basin of the
lake is not generally susceptible to anoxia
because the wind keeps the shallow basin
well mixed, preventing complete stratifica-
tion. The eastern basin is deeper and the
thick hypolimnion contains enough oxygen
to prevent anoxia.
In both Canada and the United States,
the belief that Lake Erie was 'dying' increased
public alarm about water pollution every-
where. Even the casual observer could see
that the lake was in trouble. Cladophora,
a filamentous alga that thrives under
eutrophic conditions, became the dominant
nearshore species covering beaches in green,
slimy, rotting masses. Increased turbidity
caused the lake to appear greenish-brown
and murky.
In response to public concern, new
pollution control laws were adopted in both
countries to deal with water quality problems,
including phosphorus loadings to the lakes.
In 1972, Canada and the United States signed
the Great Lakes Water Quality Agreement to
begin a binational Great Lakes cleanup that
emphasized the reduction of phosphorus
entering the lakes.
Studies were conducted to determine
the maximum concentrations of phosphorus
that could be tolerated by the lakes without
producing nuisance conditions or disturbing
the integrity of the aquatic community.
Mathematical models were then developed
to predict the maximum annual loads of
phosphorus that could be assimilated by
the lakes without exceeding the desired
phosphorus concentrations. These maximum
amounts were then included in the Great
Lakes Water Quality Agreement. Following a
1983 review of progress made through waste
treatment and detergent phosphate controls,
it was determined that control of phosphorus
from land runoff was also necessary. Ten
years later a high degree of control of point
sources had been attained through regulation,
and it was clear that target levels could be
met through additional progress in voluntary
control of nonpoint sources.
The control of phosphorus and associated
eutrophication in the Great Lakes represents
an unprecedented success in producing envi-
ronmental results through international
cooperation.
Phosphorus loads entering the lakes
have been reduced to below the maximum
amounts specified in the Agreement for Lakes
Superior, Huron and Michigan, and are at or
near maximum amounts for Lakes Erie and
Ontario. Phosphorus concentrations in the
lakes are similarly below maximum levels
in the upper lakes and at or near maximum
concentrations in Lakes Ontario and Erie. In
the shallow western basin of Lake Erie, con-
centrations are close to being within maximum
levels during calm periods, but are highly
variable due to weather and resuspension
of sediments.
The return to lower amounts of
phosphorus has not only resulted in reducing
excess growth of algae, but has also changed
the composition of the algal population.
Nuisance algal species have given way to
more desirable and historically prevalent
species, such as diatoms, thereby eliminating
nuisance conditions and improving the
quality of the food chain for other organisms.
Toxic contamination of the environment
and the potential risk to human health have
been the result of the increased production
and widespread use of synthetic organic
chemicals and metals since the 1940s. The
dangers of toxic substances in the natural
environment were first illustrated through
the study of the effects, persistence and
movement of the pesticide DDT.
Toxic pollutants include human-made
organic chemicals and heavy metals that can
be acutely toxic in relatively small amounts
and injurious through long-term (chronic)
exposure in minute concentrations. Many of
the contaminants that are present in the
environment have the potential to increase
the risk of cancer, birth defects and genetic
mutations through long-term, low-level
exposure.
Many toxic substances tend to bioaccu-
mulate as they pass up the food chain in the
aquatic ecosystem. While the concentrations
in water of chemicals such as PCBs may be
so low that they are almost undetectable,
biomagnification through the food chain can
increase levels in predator fish such as large
trout and salmon by a million times. Still
further biomagnification occurs in birds and
other animals that eat fish. There is little
doubt that bioaccumulative toxic substances
continue to affect aquatic organisms in the
lakes and birds and animals that eat them.
Public 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 com-
mercially 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. For example,
a person who eats one meal of lake trout
from Lake Michigan will be exposed to more
PCBs in one meal than in a lifetime of
drinking water from the lake.
People who consume a lot of fish and
wildlife have greater exposure to contaminants
than those who do not. Higher exposure means
greater health risks, specific 'at-rfsk' groups of
concern include native peoples, anglers and
their families, and certain immigrant groups
who rely on fish and wildlife for a large part of
their diet. Epidemiological studies of Michigan
residents have demonstrated that people
who regularly eat fish with high levels of
30
image:
PCBs have much higher concentrations
in their bodies than others. The relationship
between this exposure and effects on human
health is of concern.
Recent scientific evidence, based
mostly on observations in animals, has
raised concerns that exposure to low levels
of some contaminants may cause subtle
effects on reproduction, development and
other physiological parameters. Effects
may go easily unnoticed in the short term,
but in the long term may lead to serious
cumulative damage. New studies in the
Great Lakes basin and throughout the world
are now looking at 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. However,
certain groups may be more sensitive to the
effects of contaminant exposure, including
the developing fetus and child, the elderly
and people whose immune systems are
already suppressed. Reporting for some of
these disease states is often poor, making
population-wide assessments very difficult.
Researchers at Wayne State University
have been following from birth a group of
children born to mothers who had regularly
eaten at least 11.8 kg of contaminated Lake
Michigan fish over a 6-year period. The study
linked exposure to PCBs to decreases in birth
weight, head circumference and gestational
age of the new-born infants. Follow-ups of the
children have documented subtle deficits in
short-term memory and certain cognitive skills.
The extent to which these deficits are a result
of contaminant exposures is still a subject of
great debate, prompting other researchers to
conduct similar studies in human subjects and
laboratory studies with rats.
Concentrations of PCBs and other toxic
contaminants in Great Lakes fish have declin-
ed significantly since the exposure of the
mothers in the study took place. Contaminants
in breast milk have also declined. Despite
this progress, contaminant levels in fish still
remain high enough to require fish consump-
tion advisories for some species and sizes of
fish. The advisories are strictest for pregnant
women and pre-teen children, to minimize
exposures and protect health.
Some of the chemicals found in the
lakes have been shown to be cancer-causing
agents (carcinogens) in high-dose animal
studies. The identification of a chemical as
a human carcinogen is often difficult, since
many years may elapse between the original
exposure to the chemical and development
of the cancer. Other external factors can
contribute to the same cancer (for example,
smoking is a common confounder in research
studies) and complicate our certainty about
the role played by a particular chemical.
There is also concern that interactions
between substances can interfere with
(by antagonism) or enhance (by synergism)
the action of another individual chemical.
The crossed bill of this Cormorant is believed
to be an effect of toxic contamination of the
food chain in isolated locations on the
lakes.
Dredging
Shipping
Storms
Biotic Disturbance
SEDIMENT HESUSPENSION. Polluted sediments that have settled out of the water can be stirred up and
resuspended in water by dredging, by the passage of ships in navigation channels, and by wind and wave
action. Sediments can also be disturbed by fish and other organisms that feed on the bottom.
There is emerging public concern over
certain contaminants that mimic hormones
in the human body, with the potential effect
of altering sexual characteristics and other
hormonal functions. DDT, one of several
chlorinated organic compounds that can
weakly mimic estrogen, is under investigation
for potential linkages to one type of breast
cancer. As well, studies are examining the
potential of TCDD, a form of dioxin, to mimic
estrogen, with the potential results of femi-
nization of sex organs in males and disruption
in the development of other sexual charac-
teristics. There are also questions about the
effects of estrogen-like compounds on sperm
quality.
Research is continuing to quantify what
the actual exposures to Great Lakes toxic
contaminants are for various at-risk groups
and the general population, and the relation-
ship between exposure and health outcomes.
In the meantime, measures must continue
to be taken to minimize exposure, to protect
health. This will certainly occur through public
education and lifestyle changes to avoid
exposures. However, cleanup and pollution
prevention are the long-term real solutions
to reducing human exposure and protecting
and promoting good health.
efforts were underway to reduce
point sources of pollution and to study
nonpoint pollution sources, it was discovered
that many pollutants are deposited from the
atmosphere. Like the precursors of acid rain,
which can originate far from where the
damage occurs, nutrients and toxic contami-
nants can be carried long distances from their
sources to be deposited in the lakes in wet
and dry forms. Atmospheric deposition of a
pollutant in the Great Lakes basin was first
recognized with phosphorus. Measurements
of rain, snow and dust fall showed that about
20 percent of the phosphorus loading to Lake
Michigan was from the atmosphere. Because
this source could not be controlled, the need
to reduce phosphorus in detergents, in
sewage treatment and from fertilizer runoff
was reinforced. Atmospheric deposition of
toxic chemicals was recognized by measure-
ments of PCBs in precipitation after these
chemicals were discovered in Great Lakes
fish in 1971. Long-range transportation of
substances was confirmed by the PCBs and
toxaphene discovered in fish from a lake on
Isle Royale, a remote island in Lake Superior
isolated from any known direct sources of the
pollutants.
image:
urest
Atmospheric
Deposition
Urban Runoff
Industrial Outfalls
Migration
Through
Groundwater
SOURCES AND PATHWAYS OF POLLUTION
Transport of substances such as PCBs is
complicated by the fact that they tend not to
stay dissolved in water and thus volatilize back
into the atmosphere or become attached to
particles. As a result, large quantities of PCBs
volatilize out of the lakes, as well as being
deposited into them from the vast reservoir
of synthetic organic chemicals moving about
in regional and global air masses.
Sediments that were contaminated
before pollutant discharges were regulated
are another source of pollution. Such in-place
pollutants are a problem in most urban-
industrial areas. Release of pollutants from
sediments is believed to be occurring in
connecting channels such as the Niagara,
St. Clair and St. Marys Rivers, in harbors
such as Hamilton, Toronto and the Grand
Calumet, and in tributaries such as the Buffalo,
Ashtabula and Black Rivers. Even where it
is possible to remove highly contaminated
sediments from harbors, removal can cause
problems when sediments are placed in
landfills that may later leak and contaminate
wetlands and groundwater. Dredging for
navigation can also present problems of
disposal of dredge spoils. Disposal of highly
polluted sediments in the open lakes has been
prohibited since the 1960s. In both the U.S.
and Canada, research and demonstration
projects are being conducted to find effective
ways to isolate, remove and destroy contam-
inated sediments.
Groundwater movement is another
pathway for pollutants. As water slowly
passes through the ground it can pick up
dissolved materials that have been buried
or soaked into the ground. Contamination of
groundwater tends to be localized near badly
contaminated sites, but it can also be wide-
spread if the pollutant was used as a pesticide.
Because treatment of groundwater is very
difficult and expensive, prevention is clearly
the best approach.
Surface runoff is the pathway for a wide
variety of substances that enter the lakes.
Nutrients, pesticides and soils are released by
agricultural activities. In urban areas, street
runoff includes automobile-related substances
such as salt, sand, asbestos, cadmium, lead,
oils and greases. Surface runoff also includes
a wide number of materials deposited with
precipitation, which may include particulates,
bacteria, nutrients and toxic substances.
LOADINGS To
A CLOSED SYSTEM
In considering pathways of pollution, it
is important to recognize that in the case of
the Great Lakes, unlike rivers that run to the
oceans, pathways end in the lakes. Regard-
less of whether pollutants are diluted by
large stream flows or temporarily stored on
sediment particles on stream bottoms, they
will eventually reach the lakes and add to the
total burden.
Because the lakes respond to total
quantities of persistent substances as well
as localized concentrations, it is important to
understand the total loading of pollutants to
each lake from all pathways. This was first
recognized for phosphorus, as reflected in
the Great Lakes Water Quality Agreement.
As laboratory capability for analysis has
improved together with the understanding
of how persistent toxic substances cycle in
the ecosystem, total loadings are becoming
known. This knowledge, together with bioac-
cumulation factors, can translate loadings into
predictable levels in biota. These develop-
ments hold the promise that the Lakewide
Management Plans called for in the Agree-
ment can provide the 'schedule of load
32
image:
reductions of Critical Pollutants that would
result in meeting Agreement Objectives'.
major progress has been made in
control of industrial and municipal discharges
to waterways, the importance of other sources
has become better understood.
Direct discharges to waterways are
known as point sources. Because such
sources have specific owners and can be
easily sampled, regulatory programs have
resulted in a high degree of control. Nonpoint
sources include urban and agricultural runoff,
airborne deposition of pollutants from
automobiles and commercial activities, and
contaminated sediments and contaminated
groundwater. Control of nonpoint sources is
made difficult by their diffuse nature, episodic
release and lack of institutional arrangements
to support their control.
Because of the myriad of widespread
contributors, nonpoint sources are far less
suited to regulatory control. As a consequence,
public education, pollution prevention and
voluntary actions are very important. The
importance of pollution prevention is gaining
increasing recognition both as an effective
means of dealing with nonpoint pollution and
in dealing with pollutants from point sources
that continue to cause problems even after
state-of-the-art treatment has been applied.
Pollution prevention focuses on eliminating
pollutants before they are produced. This
includes changing production processes and
feedstocks, and choice of environmentally
benign products by consumers.
One preventive approach has been
to ban the production/extraction and use of
certain individual chemicals and metals and
to prevent the direct discharge of others into
waterways. The production and use of DDT
were banned after it was shown that the
pesticide thinned the shells of bird eggs,
causing reproductive failures. The levels of
DDT in the environment began to decline
immediately following regulation. In the case
of PCBs, production has been banned but
their use is stiil being phased out.
The nutrients necessary for plant growth (e.g., nitrogen and phosphorus) are found at very low concentrations in most natural waters. In order to obtain
sufficient quantities for growth, phytoplankton must collect these chemical elements from a relatively large volume of water.
In the process of collecting nutrients, they also collect certain human-made chemicals, such as some persistent pesticides. These may be present in the
water at concentrations so low that they cannot be measured even by very sensitive instruments. The chemicals, however, biologically accumulate (bioac-
cumulate) in the organism and become concentrated at levels that are much higher in the living cells than in the open water. This is especially true for
persistent chemicals - substances that do not break down readily in the environment - like DDT and PCBs that are stored in fatty tissues.
The small fish and zooplankton eat vast quantities of phytoplankton. In doing so, any toxic chemicals accumulated by the phytoplankton are further concen-
trated in the bodies of the animals that eat them. This is repeated at each step in the food chain. This process of increasing concentration through the food
chain is known as biomagnification.
The top predators at the end of a long food chain, such as lake trout, large salmon and fish-eating gulls, may accumulate concentrations of a toxic chemical
high enough to cause serious deformities or death even though the concentration of the chemical in the open water is extremely low. The concentration of
some chemicals in the fatty tissues of top predators can be millions of times higher than the concentration in the open water.
The eggs of aquatic birds often have some of the highest concentrations of toxic chemicals, because they are at the end of a long aquatic food chain, and
because egg yolk is rich in fatty material. Thus, the first harmful effects of a toxic chemical in a lake often appear as dead or malformed chicks. Scientists
monitor colonies of gulls and other water birds because these effects can serve as early warning signs of a growing toxic chemical problem. They also
collect gull eggs for chemical analysis because toxic chemicals will be detectable in them long before they reach measurable levels in the open water.
Research of this kind is important to humans as well, because they are consumers in the Great Lakes food chain. Humans are at the top of many food chains,
but do not receive as high an exposure as, for example, herring gulls. This is because humans have a varied diet that consists of items from all levels of the
food chain, whereas the herring gull depends upon fish as its sole food source. Nevertheless, the concerns about long-term effects of low-level exposures
in humans, as well as impacts on people who do eat a lot of contaminated fish and wildlife, highlight the importance of taking heed of the well-documented
adverse effects already seen in the ecosystem.
Fhytoplankton
0.025 ppm
Zoopfankton
0,123 ppm
Herring Gull Eggs
124 pprn
Smelt
1J34-
Troyt
ppm
PERSISTENT ORGANIC CHEMICALS such as PCBs bioaccumulate. This diagram shows the degree of concentration in each level of the Great Lakes aquatic food chain
for PCBs (in parts per million, ppm). The highest levels are reached in the eggs offish-eating birds such as herring gulls.
image:
STATE OF
THE LAKES
I PHOSPHORUS CONCENTRATIONS
Main map represents total phosphorus
concentrations for 1991 /1992
Insert map represents total phosphorus
concentrations for 1980/1983
<0.005mg/L
0.005-0.0069
0.007-0.0099
0.010-0.0119
0.012-0.015
>0.015 mg/L
not generated
by computer
simulation
This map ol phosphorus concentrations is a
generalization produced by computer analysis. It is
intended to illustrate the change in general conditions
between two time periods and should not be assumed
to be accurate for specific sites.
PCBs IN GULL EGGS
K fo in Hcninx friJt IZfyp
Trends in average
annual concentrations
ol PCBs in herring
gull eggs at eight
colonies on the
Great lakes.
* - indicates no data
PCBs IN FISH
P2S
W
? 15
W 1
| 0.5
I
T 0
86 89
YEAR
Lake Trout
Rainbow Small
Bloater
Walleye
92
Lake Superior- Mean
concentrations ot PCBs
(ppm wet weight +/-
standard error) in whole
rainbow smelt and lake
trout (age 4). Data were
not available in
consecutive years
Lake Michigan - Mean
concentrations ol PCBs
(ppm wet weight) in
whole bloater and lake
trout (620-640 mm
mean length), Data
were not available
in consecutive years.
Lake Huron • Mean concentrations of PCBs in whole
rainbow smelt and lake trout (age 4). Data were not
available in consecutive years
Lake Erie • Mean concentrations of PCBs (ppm
wet weight +/- standard error) in whole rainbow smelt
and walleye.
Lake Ontario - Mean concentrations ot PCBs (ppm
wet weight +1- standard error) in whole rainbow smelt
and lake trout (age 4).
AREAS OF CONCERN
The diamond symbol marks areas of
concern. There are 43 Areas of Concern
in the Great Lakes basin.
GRANITE ISLAND
« S> in //.TTWIJ; Gull fjx<
DOUBLE ISLAND
Ft fa ,„ Utrriirj C.irfA /-.ia.1
1980/1983
MUGG'S ISLAND/LESLIE ST
m llrmm; Cull liiai
BIG SISTER ISLAND
rt B< in
CHANNEL SHELTER ISLAND
p Ft Jfa in Ikrrinx (M Kan
NIAGARA RIVER
FIGHTING ISLAND
Herring l.iJI Eg&
Scale 1 : 6 000 000
100 200 300 kilometres
100
150
2.5
T '5
W 1
E
i 0.5
H
T 0
YEARS
Lake Superior PCBs in Fish
80
B4
92
25
20
W
T 15
W 10
E
H
T 0
Lake Michigan PCBs in Fish
iMke Huron PCBs in Fish
Lake Erie
PCBs in Fish
200 miles
Lake Ontario PCBs in Fish
P 25
M 2.0
1.5
72 76 80 84 88 92
YEAR
H
T 0.0
3C
84 88
YEAR
p
M
W
W 2
E
G
H
T 0
80
84 88
YEAR
92
P B
S 7
W 6
E 5
T 4
W 3
f 2
S 1
T 0
80
84 88
YEAR
92
Geomatics International Cartography
image:
[ABITAT AMD
Habitat within the Great Lakes basin
has been significantly altered following the
arriva! of European settlers, especially during
the last 150 years. 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.
This, together with construction of dams and
urbanization, has created vast changes in the
plant and animal populations. Streams have
been changed not only by direct physical dis-
turbance, but by sedimentation and changes
in runoff rates due to changing land use, and
by increases in temperature caused by
removal of shading vegetation.
Wetlands are a key category of habitat
within the basin because of their importance
to the aquatic plant and animal communities.
Many natural wetlands have been filled in or
drained for agriculture, urban uses, shoreline
development, recreation and resource
extraction (peat mining). Losses have been
particularly high in the southern portions of
the basin. It is estimated, for example, that
between 70 and 80 percent of the original
wetlands of Southern Ontario have been lost
since European settlement, and losses in the
U.S. portion of the basin range from 42
percent in Minnesota to 92 percent in Ohio.
Unfortunately, some governments continue -
to encourage this practice through drainage
subsidies to farmers. The loss of these lands
poses special problems for hydrological
processes and water quality because of the
natural storage and cleansing functions of
wetlands. Moreover, the loss makes difficult
the preservation and protection of certain
wildlife species that require wetlands for part
or all of their life cycle.
Biodiversity refers to both the number
of species and the genetic diversity within
populations of each species. Some species
have become extinct as a result of changes
within the Great Lakes basin and many others
are being threatened with extinction or loss
of important genetic diversity. Recovery of
some highly visible species such as eagles
and cormorants has been dramatic, but other
less known species remain in danger.
The loss of genetic diversity or variability
within a species is a less well understood
problem. An example is the loss of genetic
stocks of fish that instinctively spawn or feed
in certain areas or under certain conditions.
This is thought to be a factor in the lack of
recovery of some species such as lake trout,
which are apparently not able to sustain
naturally reproducing populations except in
Lake Superior. Even in Lake Superior all of the
genetic strains of lake trout that once spawned
in tributaries have been lost. Lack of diversity
within a species can also increase the vulnera-
bility of the population to catastrophic loss
caused by disease or a major change in envi-
ronmental conditions.
As many forms of pollution have been
controlled and reduced, the importance
of habitat is being recognized as critically
important to the health of the Great Lakes
ecosystem. As the physical, chemical and
biological interactions of the ecosystem are
becoming better understood, it has become
apparent that no one component can be
viewed in isolation. To protect any living
component, its habitat and place within the
system must be protected.
equally important cause of change
has been the introduction of exotic, i.e., non-
native, species of plants and animals. In the
lakes, sea lamprey, carp, smelt, alewife,
Pacific salmon and zebra mussels, to name
just a few, have had highly visible impacts.
The effects of hundreds of other invading
organisms are less obvious, but can be
profound. On land, invading plants such as
purple loosestrife and European buckthorn
continue to displace native species. In some
areas, major changes in terrestrial plant com-
munities have been caused by suppression
of fire. All of these disturbances have resulted
in changes in aquatic and terrestrial habitat,
causing further changes in plant and animal
populations. The collective result has been
the disruption of the complex communities
of plants and animals that had evolved
during thousands of years of presettlement
conditions. Destruction of these complex
communities by changes in land use or by
invasion by exotic species has resulted in
loss of biodiversity.
In 1971, the first sport fish advisory was issued in the Great Lakes for people consuming fish caught
from the lakes. These advisories, issued by state and provincial governments, recommended that
consumption of certain species and sizes of sport-caught fish should be limited or avoided because
of toxic chemicals present in the fish. Advisories are now issued on a regular basis to limit exposure
and protect health.
Because of current scientific uncertainty about the toxicity of these chemicals to humans, the juris-
dictions surrounding the lakes vary in the advice they provide. However, in all cases, following the
advisories will reduce the exposure to contaminants, and therefore the risk of suffering adverse
effects. People who consume large quantities of sport-caught fish should pay close attention to the
advisories. Because the developing fetus and child are most susceptible to the adverse effects of
exposure, the fish consumption guidelines are strictest for women of child-bearing age, pregnant
women and pre-teen children.
Fish provide important nutrition to people and, while following advisories can reduce exposure, fish
can also be prepared and cooked in certain ways so as to reduce or eliminate a large proportion of
certain contaminants. Since some persistent contaminants accumulate in fatty tissue, trimming
visible fat and broiling rather than frying so that fat drips away will reduce a large proportion of
these contaminants in fish. Limiting consumption of fish organs will reduce exposure to mercury.
Fish advisory information in the form of fish guides or pamphlets often includes this fish preparation
information. Consumers should contact their public health and environmental agencies for further
information about fish advisories and preparing and eating fish from the Great Lakes or their
tributaries.
SUSTAINABLE
Pollution prevention, protecting and
restoring habitat, protecting biodiversity,
understanding the ecosystem and cleaning
up old pollution problems are all a part of
sustainable development. The term 'sustain-
able development' first gained visibility in
the report of the World Commission on
Environment and Development, commonly
known as the Bruntland Commission. The
report, entitled 'Our Common Future',
defined the concept generally as 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. If the Parties
to the Great Lakes Water Quality Agreement
are to fulfill its purpose 'to restore and
maintain the chemical, physical and
biological integrity of the waters of the
Great Lakes Basin Ecosystem' it is clear
that attaining sustainable development
within both countries is essential.
A major test of whether sustainable
development has been achieved will be
whether this integrity has been restored
or maintained. The concept of integrity of
an ecosystem recognizes that ecosystems
contain mechanisms that create both
stability and resiliency within them. Integrity
35
image:
4 j Thu Or
ftp
36
The Great Lakes Water Quality Agreement
lists 14 beneficial uses that may be impaired
and in need of restoration. The four general
categories below contain the 14 impairments
identified by number based upon the sequence
in which they appear in the agreement.
Degradation offish and wildlife
populations (3)
Degradation of benthic populations (6)
Degradation of phytopiankton and
zooplankton (13)
Undesirable algae/eutrophication
{which may cause low dissolved
oxygen levels, which may, in turn,
cause other impairments) (8)
Fish tumors and other deformities (4)
Bird or animal deformities or
reproduction problems (5)
Restrictions on fish and wildlife
consumption (1)
Beach closings (bacteria} (10)
USE
Tainting of fish and wildlife flavor (2)
Restrictions on dredging (7)
Taste and odor in drinking water (9)
Degradation of aesthetics (11)
Added costs for agriculture or
industry (12)
1C
Concern:
i
Area of Concern
LAKE SUPERIOR
LAKE MICHIGAN
LAKE HURON
LAKE ERIE
LAKE ONTARIO
CONNECTING CHANNELS
Peninsula Harbour
Jackfish Bay
\ Nipigon Bay
Ecological Health
and Reproduction
Is, 6
Habitat
Human Health
14 f 1
_J,_J,_5? ,14
M?
137^ 171 14 1
Thunder Bay !~3, *. 5?, 6, 13 ~ ^"14 r1, 10
St. Louis Bay/River
Torch Lake
! 3, 4, 5?, 6
6
j_J!_____u 1. 10
J3ejrJ.§ke:Cjrrj_Creek/River
Manistique River ~~| " 6
Menominee River
Fox River/Southern Green Bay
Sheboygan River
Milwaukee Estuary
^tfauj<ejanj|ajtr£_____
3, 6
1 A
14
3, 4?, 5, 6, 8, 13^] 14
3, 4, 5, 6, 8, 13
1374, 5, 8, 8, 13
3?, 5?, 6, 13
-^o— —
Human Use/
Welfare
L^^il^
6, 7,
2, 7,
7,
11
11
11, 12
2?, 7, 11
7,
11
__l_JQ L__l_
rTTTo |2t O,
14 L 1
14
14
11
7
1, 10 7,
11
, 1, 10 1 2?, 7, 9?
Grand Calumet River/Indiana HarborCanaTT 3, 4, 5, 6, 8, 13 14 1, 10 | 2, 7, 9,
Kafamazoo River
MusksgonLake^
White Lake
__Sj£inaw_RJvef/BaY_
Collingwood Harbour
Severn Sound
Spanish Harbour
Clinton River
Rouge River
River Raisin
I _____
Black River
Cuyahoga River
Ashtabula River
Presque Isie Bay
Wheattey Harbour
5?
3, 5?, 6, 8, 13?
14
14
1
3, 5?, 6, 8, 13? ! 14~ ["I
1, 9,
7, 9,
3, 5, 6, 8, 13 i 14 __,kJ0 j_J' 1> 9'
__________77___^___^7^T7^^
Hr~~nrr~i4iit^^ ~pr~
IT 5^6?, 13? 14?
3, 4, 6, 8, 13
3, 4, 6, 8
6
3, 4, 6, 8
14
_Lio _j
1, 10
rTlo
I 1
_ . ,___ . ,
3 4 JLJIJLJ3JLJ_14
3, 4, "5?rO!l3TTl4
3, 4, 6
14
4, 6?_ j
4?, 6?, 8?
Buffalo River ' TZZITS^HCB l
Eighteen Mile Creek
Rochester Embayment
Oswego River
Bay of Quinte
r» , u
rort Hope
Metro Toronto
6? i
3, 4?, 5, 8, 8, 13
3, 4?, 5?, 6?, 8, 13?
3, 4?, 6, 8, 13
3, 4?, 5?, 6, 8, 13?
Hamilton Harbour | 3, 4, 5, 8, 8
St. Marys River I
St. Clair River " I
3, 4, 6, 8 _J
4?, 5, 6
Drtroitjiver _______^S
___ : ~ j|T 5, 6, 8, 13?
_Ni§jjara River (New York) I 3? 4, 5? 6
St. Lawrence River (Cornwall) (3. 4, 5, 6, 8, 13?
St. Lawrence River (Massena) [ 3?, 4?, 5?, 6?, 13?
14
_ _ _,
7,
rzmzn
L T,
7,
7
7, 9,
1, 10 I 2?, ]_,__
11, 12
11
11
Jj
11
12
11
11
11
11
11
_L___J 7
10
10?
1 1
7
7
2?, 7
14? 1? 7?
14.
14 ^^
14
14
14
14
14
14
14
1, 10 f 2?, 9,
_J_______ZJ
_____ 7^J
1, 10
1
1, 10
1' 10 J
1, 10
11, 12
11?
7, 9,
11
7
7,
7,
7,
2?, 7, 9,
7, 9,
1, 10 1 7, 9
11
11
11
11, 12
11
14 "^ 1 j 7
14
1, 10 j 2?, 7, 9,
11, 12
14 [1 1
Symbols used: The numbers identify specific use-impairment categories used in the Great Lakes Water Quality Agreement.
Question marks indicate impairments being investigated.
Adapted from: Progress in Great Lakes Remedial Action Plans 1994. OF: 6/8/94
i AREAS OF CONCERN: 43 areas were initially identified where the use of water had been impaired by continuous pollution or where the objectives of the Great Lakes Water Quality Agreement and local standards were not being achieved.
Studies and remedial action plans are being undertaken for many of the areas. One area, Collingwood Harbour, has been cleaned up and delisted as an Area of Concern.
image:
includes the capacity of the system to remain
intact, to self-regulate in the face of internal
or external stresses and to evolve toward
increasing complexity and integration.
©verail, water quality in the lakes is
improving due to the progress that has been
made in controlling direct discharges of
wastes from municipalities and industries
under environmental laws adopted since the
1960s. Even so, some areas still suffer serious
impairment of beneficial uses (drinking,
fishing, swimming, etc.) and fail to meet
environmental standards and objectives.
Serious problems remain throughout
the basin in locations identified as '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. The purpose of establishing Areas of
Concern is to encourage jurisdictions to form
partnerships with local stakeholders to reha-
bilitate these acute, localized problem areas
and to restore their beneficial uses. In these
areas, existing routine programs are not
expected to be sufficient to restore ecosystem
quality to acceptable levels and special efforts
are needed. Jurisdictions are implementing
Remedial Action Plans (RAPs) to guide specific
rehabilitation activities in all 42 areas (one
Area of Concern - Collingwood Harbour -
has been cleaned up).
Most UC 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. Pollutants are concentrated in
these areas because of long-term accumula-
tion of contaminants deposited from local
point and nonpoint sources and from
upstream sources. Nearly all the Areas
of Concern have contaminated sediments.
Over the last decade, the nature of
the problems associated with some areas
has changed. For instance, as progress was
made in restoring dissolved oxygen and
reducing some toxic substances such as
lead and mercury, it became apparent that
the problem of dissolved oxygen had been
obscuring other problems of toxic contami-
nation. In these areas, continued remedial
and preventive action is necessary.
RAPs are unique in their emphasis
on multi-disciplinary, multi-agency, multi-
stakeholder partnerships. By developing a
locally based consensus on environmental
problems, their causes and the key steps
needed to solve them, RAPs provide a clear
basis for action and accountability on the
part of those responsible for taking action.
JUr pollution is often neglected when
talking about water quality and health.
Through long-range transport, persistent
toxic contaminants are deposited in the
Great Lakes. They then become available
to living things through the food chain.
Acid precipitation created by continued
use of fossil fuels in the transportation sector
and in the production of electrical power, as
well as from smelter emissions, may seriously
affect the quality of aquatic ecosystems. Small
lakes and tributaries that feed the Great
Lakes are most susceptible. Because of the
underlying sedimentary limestone in the
lower Great Lakes, there is a natural capacity
to buffer the effects of acid rain. However,
concern remains for the lakes and tributaries
originating in the northern forest on the
Canadian Shield. In Ontario, Minnesota,
Michigan and Wisconsin, acidification is
already evident in many small lakes.
Smog has become a concern for people
residing in the Great Lakes basin. Motor
vehicle emissions concentrated in urban
areas are a major contributor to the smog
problem. Ground-level ozone is a major
component of smog in the lower Great
Lakes basin. Recent research has shown
an increase in hospital admissions for
respiratory illness on days when ground-
level ozone and sulfate levels exceed
guidelines.
The shoreline of the Great Lakes is under
continual stress. In the lower lakes region
little remains undeveloped. Most lakefront
properties are in private ownership and thus
under limited control by public authorities
wishing to protect them. Erosion losses are
high because of intensive development and
A number of proposals have been made for large-scale diversion of water from water-rich regions
of North America to water-poor areas experiencing growth in population and industry. The plans
generally call for interbasin transfer of Great Lakes water or Canada's Arctic fresh waters southward
to the western U.S. Massive engineering schemes needed to do this have often been proposed by
private entrepreneurs interested in selling the water or benefiting from improved water supply to
their area.
In the 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 by
a system of canals and rivers. Efforts to revive IMAWAPA in the 1970s failed.
At the direction of the U.S. Congress the U.S. Army Corps of Engineers suggested diversion of water
from the Great Lakes via the Mississippi River to compensate for rapid depletion of groundwater from
the Ogallala aquifer in the high plains states of Nebraska, Kansas, Oklahoma and Texas. A 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.
The Great Recycling and Northern Development (GRAND) Canal concept was revived in 1985 after
being proposed in the 1950s. 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 $100 billion (Canadian) and the support of
Ontario and Quebec, all the Great Lakes states as well as the federal governments of both countries.
Invariably the proposals have failed to materialize for economic reasons. Increasingly, however,
opposition to these proposals is based on environmental concerns because the environmental
impacts of large-scale diversions have not been adequately assessed. In the 1985 Great Lakes
Charter all the state governors and the premiers of Ontario and Quebec agreed to cooperate in
consideration of any proposed diversion.
loss of vegetative cover and other natural
protection. Damages due to flooding are also
of concern, particularly during periods of high
lake levels. Flooding and erosion damages to
private property lead to public pressure on
governments to further regulate lake levels
through diversion manipulation and control
structures on outlet channels (see Chapter
Three). The demand for public access to the
lakes for recreation has grown steadily in
recent years and can be projected to continue.
Currently, the greatest growth is in the
development of marinas for recreational
boating.
Some consideration has been given
to the sale of water as a commodity to
fast-growing water-poor areas such as the
American Midwest and Southwest. These
range from proposals for minor diversions
out of the basin to mega-projects that would
see large-scale alterations to the natural
flows from as far away as James Bay,
through the Great Lakes basin to the
American sunbelt states. Opposition to such
suggestions comes from environmentalists
and others who fear the enormous conse-
quences of such large-scale manipulation
of the natural watersheds.
Climate change is a long-terra threat to
the Great Lakes ecosystem. If it caused lower
lake levels, it would reduce shore erosion,
but would, at a minimum, cause problems
for navigation and wetlands. The ecosystem
has survived changes in climate before, but
global warming could occur in a far shorter
time span, leaving insufficient time for plant
species to adapt or move to favorable sites.
It would be a tragic irony if, because of
our failure to deal with the pollution of the
lakes and the effects of our development
of the basin, we look out over the vast
expanse of the lakes and realize that we
have permanently damaged a sustaining
natural resource.
37
image:
MAJOR WETLANDS
There are numerous wetlands in
northern Ontario and elsewhere
that are too small to show
individually ai this scale.
ECOREGIONS, WETLANDS
AND DRAINAGE BASINS
CANADIAN ECOREGIONS
Lake St. Joseph Plains
Nipigon Plains
Thunder Bay Plains
Superior Highlands
Matagami
6 | Chapleau Plains
T\ Nipissing
8~~| Hurontario
Erie
10 I Saint Laurent
NOTE:
Ecoregions are areas that exhibit broad ecological
unity, based on such characteristics as climate,
landforms, soils, vegetation, hydrology and wildlife
"NTl 20 'XA V'"~
itoulin
Bruce
PeninsulaX t
/ Winncht
/ :.'«..•
K™ A
SCALE 1:5 000 000
50 100 150 200 250 kilometres
DRAINAGE BASINS
Great Lakes Basin
Lake Basins
Sub Basins
UNITED STATES ECOREGIONS
| II j Northeastern Highlands
| 12 | Erie/Ontario Lake Plain
Pl3 ] Northern Appalachian Plateau and Uplands
l_l_4j Eastern Corn Belt Plains
I 15 | Huron/Erie Lake Plain
| 16 | Southern Michigan/Northern Indiana Clay Plains
^| Central Corn Belt Plains
| 18 | Southeastern Wisconsin Till Plain
\19 | North Central Hardwood Forests
I 20 I Northern Lakes and Forests
0 25 50 75 100 125 150 175 miles
ftrock University Cartography
image:
The concept of an ecosystem approach
to management of the Great Lakes has deve-
loped out of the joint experience of Canada
and the United States. An evolution in under-
standing how environmental damage has
resulted from human use of natural resources
in the basin has arisen out of the research,
monitoring and commitment to Great Lakes
protection by the governments and citizens
of both countries. Out of this evolution has
come the need for participation at many
levels. Ecosystem management requires the
involvement of ail levels of government, as
well as industry and non-government organi-
zations, each with their own responsibilities,
and often working in partnership to protect
the basin ecosystem.
Originally, water pollution was treated as
a separate problem. As experience demon-
strated connections between use of land, air
and water resources, appreciation grew for
the need to consider relationships within the
ecosystem. Concern about protection and
use of waters that are shared by the United
States and Canada led to the creation of
institutions that foster joint management.
The first changes that become apparent
due to intensive settlement and development
were considered local and specific. Initially,
solutions to problems such as bacterial conta-
mination near cities, sedimentation of tributary
mouths and industrial pollution were handled
locally. Usually the solutions involved dilution
or displacement of polluted discharges to
other locations. Eventually pollution that had
been local began to affect whole lakes and
then became basin-wide concerns.
in 1905 the International Waterways
Commission was created to advise the govern-
ments of both countries about levels and flows
in the Great Lakes, especially in relation to
the generation of electricity by hydropower.
Its limited advisory powers proved inadequate
for problems related to pollution and environ-
mental damage. One of its first recommenda-
tions was for a stronger institution with the
authority for study of broader boundary
water issues and the power to make binding
decisions.
The Boundary Waters Treaty was signed
in 1909 and provided for the creation of the
International Joint Commission (IJC). The UC
has the authority to resolve disputes over the
use of water resources that cross the interna-
tional boundary. Most of its efforts for the
Great Lakes have been devoted to carrying
out studies requested by the governments
and advising the governments about
problems.
In 1912, water pollution was one of the
first problems referred to the UC for study.
In 1919, after several years of study, the IJC
concluded that serious water quality problems
required a new treaty to control pollution.
However, no agreement was reached.
Additional studies in the 1940s led to
new concerns by the IJC. The Commission
recommended that water quality objectives
be established for the Great Lakes and that
technical advisory boards be created to
provide continuous monitoring and surveil-
lance of water quality.
Public and scientific concern about pollu-
tion of the lakes grew as accelerated eutrophi-
cation became more obvious through the
1950s. In 1964, the IJC began a new reference
study on pollution in the lower Great Lakes.
The report on this study in 1970 placed the
principal blame for eutrophication on exces-
sive phosphorus.
The study proposed basin-wide efforts to
reduce phosphorus loadings from all sources.
It was recognized that reduction of phosphorus
depended on control of local sources. Uniform
effluent limits were urged for all industries
and municipal sewage treatment systems
Communities, local groups and individuals play a key role in the management of the Great Lakes. The management
process starts with individuals end families taking action as consumers, recyclers, neighborhood stewards and
health promoters. Non-government organizations are taking responsibility for public education, citizen-directed
projects, and for providing direction to government. Businesses are key in managing their own operations in a
sustainable, ecological fashion, being partners with community and governments, and in complying with regulations
set by themselves and others. Most successful management requires partnership arrangements among the various
sectors in the public.
People are getting involved in local decision-making processes, via groups such as Public Advisory Committees in
Areas of Concern and local community groups throughout the Great Lakes basin that exert pressure toward change.
Residents are seizing the opportunity to participate in local Town Hall' meetings and community consultations, to
ask questions, get useful information and provide feedback as to the local issues they feel are of priority to be
addressed.
People and communities are also playing an active role by getting involved in clean-up activities such as beach
sweeps and rehabilitation projects to restore local watersheds and habitats. Personal lifestyle changes such as
recycling, responsible disposal of household and automotive products, and adopting practices that are less polluting
also play a role in reducing and preventing pollution.
6
39
image:
5 | JoiiiS JJanasiemiBiit of She (JlfisaS Lakes
SHBI '
The Great Lakes Water Quality Agreement recognizes that control procedures, research and
monitoring would continue to be conducted by the two countries within their respective legislative
and administrative structures.
Because of their obligations under the Agreement, both governments have established special
programs for the Great Lakes.
In Canada, the British North America Act assigns the authority for navigable waters and international
waters to the federal government, while pollution control and the management of natural resources
are primarily provincial responsibilities. Consequently, the initiative to establish water quality
objectives under the Great Lakes Water Quality Agreement has been federal/provincial, and the
implementation has been primarily a provincial responsibility.
The federal Canada Water Act provides for federal/provincial agreements setting out responsibilities
for both levels of government. The Canada/Ontario Agreement provides for joint work on activities
required by the Great Lakes Water Quality Agreement.
In 1988, the Canadian Environmental Protection Act (CEPA) was developed, and provides a framework
for controlling toxic substances. For example, under this act, dioxins and furans will be virtually
eliminated from pulp and paper mill discharges.
The lead agency at the federal level is Environment Canada. The Department of Fisheries and Oceans
is a major contributor of scientific and research support to Canada's Great Lakes program. Other federal
departments directly involved include the Department of Health, Agriculture and Agrifood Canada,
Transport Canada and the Department of Government Services.
The major responsibility for water quality at the provincial level rests with the Ontario Ministry of
Environment and Energy (MOEE). The MOEE is responsible for establishing individual control orders
for each industrial discharger. It also provides funding for sewage treatment. The Ontario Ministry of
Natural Resources provides leadership for fisheries, forestry and wildlife management.
In the U.S., many federal environmental laws affect the lakes, including the Clean Water Act, the
Resource Conservation and Recovery Act, the Toxic Substances Control Act, the Comprehensive
Environmental Response and Recovery Act (Superfund) and the National Environmental Policy Act.
These statutes provide federal regulatory authority, but it is federal policy to delegate regulatory
authority to the state governments wherever possible. The states have their own laws and operate
using both state and federal funding.
Two considerations determine the level of control required by U.S. laws. The first requires all municipal
and industrial dischargers to meet minimum national effluent standards for pollution control. Secondly,
if further limits are necessary to meet ambient environmental standards, tighter limits can be imposed.
For meeting U.S. obligations under the Great Lakes Agreement, the U.S. Environmental Protection
Agency (EPA) has the load responsibility. Numerous other agencies also have important roles,
particularly the U.S. Fish and Wildlife Service, the U.S. National Biological Service and the U.S.
Coast Guard.
The federal government supports Great Lakes Research in several agencies. The Great Lakes National
Program Office in the EPA regional offices at Chicago provides funding for applied research and co-
ordinates its activities with EPA research laboratories in Grosse lie, Michigan, Duluth, Minnesota and
elsewhere.
The National Oceanic and Atmospheric Administration (NOAA) has a Great Lakes Environmental
Research Laboratory and the U.S. Fish and Wildlife Service maintains laboratories at the National
Fisheries Center in Ann Arbor, Michigan. The Army Corps of Engineers carries out research on
water quality as well as water quantity. A network of Sea Grant College programs is supported by
state and federal funding at universities in seven of the Great Lakes states.
in the basin. Research suggested that land
runoff could also be an important source of
nutrients and other pollutants into the lakes.
The result of the reference study was the
signing of the first Great Lakes Water Quality
Agreement in 1972.
I THE GREAT LAKES
Puring the 1950s and 1960s, problems
on the Great Lakes came to a head. The
parasitic sea lamprey had decimated fisheries
as it invaded further into the waterway. !n
1955 the binational Great Lakes Fishery
Commission was established to find a means
of control for the lamprey. By the late 1970s
the lamprey population had been reduced
by 90 percent with use of selective chemicals
to kill the larvae in streams. Since then, the
Fishery Commission has expanded its
activities to include work to rehabilitate the
fisheries of the lakes and to coordinate
government efforts to stock and restore fish
populations.
T:
The Great Lakes Water Quality
Agreement established common water
quality objectives to be achieved in both
countries and three processes that would be
carried out binationally. The first is control of
pollution, which each country agreed to
accomplish under its own laws. The chief
objective was reduction of phosphorus levels
to no more than 1 ppm (mg per titre) in
discharges from large sewage treatment
plants into Lakes Erie and Ontario together
with new limits on industry. Other objectives
included elimination of oil, visible solid
wastes and other nuisance conditions.
The second process was research on
Great Lakes problems to be carried out sepa-
rately in each country as well as cooperatively.
Both countries established new Great Lakes
research programs. Major cooperative research
was carried out on pollution problems of the
upper Great Lakes and on pollution from land
use and other sources.
The third process was surveillance
and monitoring to identify problems and
to measure progress in solving problems.
Initially, water chemistry was emphasized
and levels of pollutants were reported. Now,
the surveillance plan is designed to assess
the health of the Great Lakes ecosystem and
increasingly depends on monitoring effects
of pollution on living organisms.
The Agreement provided for a review of
the objectives after 5 years and negotiation of
a new agreement with different objectives if
necessary. Tangible results had been achieved
when the review was carried out in 1977. The
total discharge of nutrients into the lakes had
been noticeably reduced. Cultural, or human-
made eutrophication, bacterial contamination
and the more obvious nuisance conditions in
rivers and nearshore waters had declined.
However, new problems involving toxic
chemicals had been revealed by research and
the surveillance and monitoring program.
Public health warnings had been issued
for consumption of certain species of fish in
many locations. Sale of certain fish was pro-
hibited due to unsafe levels of PCBs, mercury
and, later, mirex and other chemicals. In 1975,
discovery of high levels of PCBs in lake trout
on Isle Royale in Lake Superior demonstrated
that the lakes were receiving toxic chemicals
by long-range atmospheric transport. These
developments and the results of studies that
were carried out after the 1972 Agreement
set the stage for the next major step in Great
Lakes management.
Fish kills of the type seen here prompted citizens to
demand that remedial action be taken to improve
water quality on the Great Lakes.
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The 1909 Boundary Waters Treaty established the International Joint Commission of Canada and the United States. The treaty created a unique process for
cooperation in the use of all the waterways that cross the border between the two nations, including the Great Lakes.
The IJC has six members, three appointed from each side by the heads of the federal governments. The authors of the 1909 Boundary Waters Treaty saw
the Commission not as separate national delegations, but as a single body seeking common solutions in the joint interests of the two countries. AH members
are expected to act independently of national concerns, and few UC decisions have split along national lines.
The IJC has three responsibilities for the Great Lakes under the original treaty. The first is the limited authority to approve applications for the use, obstruction
or diversion of boundary waters on either side of the border that would affect the natural level or flow on either side. Under this authority, it is the IJC that
determines how the control works on the St. Marys River and the St. Lawrence River will be operated to control releases of water from Lakes Superior and
Ontario. It also regulates flows into Lake Superior from Long Lake and Lake Ogoki.
The second responsibility is to conduct studies of specific problems under references, or requests, from the governments. The implementation of the recom-
mendations resulting from IJC reference studies is at the discretion of the two governments. When a reference is made to the IJC, the practice has been to
commission a board of experts to supervise the study and to conduct the necessary research. A number of such studies have been undertaken in the history
oftheiJC.
The third responsibility is to arbitrate specific disputes that may arise between the two governments in relation to boundary waters. The governments may
refer any matters of difference to the Commission for a final decision. This procedure requires the approval of both governments and has never been invoked.
In addition to these specific powers underthe 1909 Treaty, the IJC provides a procedure for monitoring and evaluating progress under the Water Quality
Agreement. For this purpose, two standing advisory boards are called for in the Agreement.
The Water Quality Board is the principal advisor to the Commission and consists mainly of high-leve! managers from federal, state and provincial agencies
selected equally from both countries. Its responsibilities include evaluating progress being made in implementation of the Agreement and promoting coordi-
nation of Great Lakes programs among the different levels of government.
The Science Advisory Board consists primarily of government and academic experts who advise the Water Quality Board and the IJC about scientific findings
and research needs. The Council of Great Lakes Research Managers, in addition to the Science Advisory Board, was established to provide effective guidance,
support and evaluation for Great Lakes research programs. Both groups have substructures involving special committees, task forces and work groups to
address specific issues.
The IJC relies on work done by the various levels of the two governments and the academic community. It maintains an office in each of the national capitals
and a Great Lakes Regional Office in Windsor, Ontario. The Great Lakes Office provides administrative support and technical assistance to the boards and a
public information service for the programs of the Commission.
The Upper Lakes Study concluded that
phosphorus objectives should be set for
Lakes Huron, Michigan and Superior. This
development was significant because it
recognized the Great Lakes as a single
system and called for joint management
objectives for Lake Michigan and its
tributaries that had not previously been
considered boundary waters.
The study on pollution from land use
and other nonpoint sources was known as
PLUARG (Pollution from Land Use Activities
Reference Group). The study demonstrated
that runoff from agriculture and urban areas
was affecting water quality in the Great Lakes.
This significant development confirmed that
control of direct discharge of pollution from
point sources alone into the Great Lakes and
tributaries would not be enough to achieve
the water quality objectives. It also called for
control of nonpoint pollution into the Great
Lakes from land runoff and the atmosphere.
The experience underthe 1972 Agree-
ment demonstrated that despite complex
jurisdictional problems, binational joint
management by Canada and the United
States could protect the Great Lakes better
than either country could alone. In 1978, a
new Great Lakes Water Quality Agreement
was signed that preserved the basic features
of the first Agreement and built on the
previous results by setting up a new stage
in joint management.
i the 1972 Agreement, the new
Agreement called for achieving common
water quality objectives, improved pollution
control throughout the basin and continued
monitoring by the IJC. As part of improved
pollution control, the 1978 Agreement called
for setting target loadings for phosphorus for
each lake and for virtual elimination of dis-
charges of toxic chemicals. The target loadings
were a step toward a new management goal
that has come to be called 'an ecosystem
approach.'
In contrast to the earlier Agreement
that called for protection of waters of the
Great Lakes, the 1978 Agreement calls for
restoring and maintaining 'the chemical,
physical and biological integrity of the
waters of the Great Lakes Basin Ecosystem.'
The ecosystem is defined as 'the interacting
components of air, land and water and living
organisms including man within the drainage
basin of the St. Lawrence River.'
In calling for target loadings for phos-
phorus, the 1978 Agreement introduced the
concept of mass balance into Great Lakes
management. A target loading is the level that
will not cause undesirable effects, including
over-production of algae and anoxic con-
ditions on fake bottoms. The mass balance
approach calculates the amount of pollutant
that remains active after all sources and losses
are considered. All sources of phosphorus
are considered in setting the controls that are
needed to reach the target loading. Formerly,
phosphorus control was based on setting
effluent limits to reduce pollution from direct
discharges. Target loadings based on mass
balance use mathematical models to deter-
mine levels of control that should protect the
integrity of the ecosystem.
The 1978 Agreement called for virtual
elimination of the discharge of persistent toxic
chemicals because of severe and irreversible
damage from bioconcentration of toxic sub-
stances present at very low levels in water.
The effects include birth defects and repro-
ductive failures in birds, and tumors in fish.
image:
Success in reducing phosphorus load-
ings under the Great Lakes Water Quality
Agreement has provided a model to the world
in binational resource management. The use
of the mass balance approach for phosphorus
set the stage for the much more difficult task
of controlling toxic contamination. Further
progress in cleaning up pollution from the past
and preventing future degradation depends
on fully applying an ecosystem approach to
management.
in 1987, the Agreement was revised to
strengthen management provisions, call for
development of ecosystem objectives and
indicators, and address nonpoint sources of
pollution, contaminated sediment airborne
toxic substances and pollution from contami-
nated groundwater. New management
approaches included development of
Remedial Action Plans (RAPs) for geographic
Areas of Concern and Lakewide Management
Plans (LAMPs) for Critical Pollutants.
The ecosystem approach was strength-
ened by calling for development of ecosystem
objectives and indicators, and by focusing RAPs
and LAMPs on elimination of impairments
of beneficial uses. The uses include various
aspects of human and aquatic community
health and specifically include habitat. By
clearly focusing management activities on
endpoints in the living system, additional
meaning is given to the goal of restoring and
maintaining the integrity of the Great Lakes
basin ecosystem.
The agreement to prepare Lakewide
Management Plans includes a commitment to
develop a schedule of reductions in loads of
critical pollutants entering the lakes in order to
meet water quality objectives and restore
beneficial uses. Thus the mass balance
concept developed for phosphorus is being
applied to control of toxic substances into the
Great Lakes. Although total elimination of
toxic substances from the Great Lakes basin
is the goal, the mass balance approach can
be used to set priorities and direct pollution
control efforts.
!,COSYS
The adoption of an ecosystem approach
to management is the result of growing under-
standing of the many interrelated and interde-
pendent factors that govern the ecological
health of the Great Lakes. An ecosystem app-
roach does not depend on any one program
or course of action. Rather it assumes a more
comprehensive and interdisciplinary attitude
that leads to wide interpretation of its practical
meaning. Certain basic characteristics, how-
ever, mark the ecosystem approach.
First, it takes a broad, systemic view of
the interaction among physical, chemical and
biological components in the Great Lakes
basin. The interdependence of the life in the
lakes and the chemical/physical characteris-
tics of the water is reflected in the use of
biological indicators to monitor water quality
and changes in the aquatic ecosystem.
Examples include the use of herring gull eggs
as an indicator of toxic pollutants, algal blooms
as an indicator of accelerated eutrophication
and changes in species composition of
aquatic communities as an indicator of habitat
destruction. Biomonitoring for chronic toxicity
can use zooplankton and phytoplankton to
measure the effects of long-term exposure to
low levels of a toxic chemical on growth and
reproduction.
Second, the ecosystem approach is geo-
graphically comprehensive, covering the entire
system including land, air and water. New
emphasis on the importance of atmospheric
inputs of pollutants and the effects of land
uses on water quality are evidence of the
broad scope of management planning required
in an ecosystem approach.
Finally, the ecosystem approach includes
humans as a major factor in the well-being
of the system. This suggests recognition
of social, economic, technical and political
variables that affect how humans use natural
resources. Human culture, changing lifestyles
and attitudes must be considered in an eco-
system approach because of their effects on
the integrity of the ecosystem.
The ecosystem approach is a departure
from an earlier focus on localized pollution,
management of separate components of the
ecosystem in isolation and planning that
neglects the profound influences of land uses
on water quality. It is a framework for decision
making that compels managers and planners
to cooperate in devising integrated strategies
of research and action to restore and protect
the integrity of the Great Lakes ecosystem
for the future. The evolution of management
programs toward a full ecosystem approach
is still in its early stages, but progress is
being made.
42
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Earlier chapters have described the
resources of the Great Lakes, how humans
have used and benefited from them, and the
physical, biological and chemical impacts
of human activity. As the story of the Great
Lakes unfolds, the importance of protecting
and preserving the lakes is highlighted. The
previous chapter mapped the development
of an involved, broad-based 'community' of
Great Lakes concern. Citizens from all sectors
of society are discovering their own personal
connection to the Great Lakes. As a result,
they are becoming increasingly involved in
actions to protect and preserve this vital
ecosystem.
and habitats of the Great Lakes basin is
needed to support protection and rehabilita-
tion of the biodiversity of the ecosystem
and to strengthen management of natural
resources. Wetlands, forests, shorelines and
other environmentally sensitive areas will
have to be more strictly protected and, in
some cases, rehabilitated and expanded.
As health protection measures are taken
and environmental cleanup continues, reha-
bilitation of degraded areas and prevention of
further damage are being recognized as the
best way to promote good health, and protect
and preserve the living resources and habitats
of the Great Lakes.
The surge of public involvement in
management of the Great Lakes reflects the
change in attitudes toward the lakes over the
years. The belief in earlier times that the
effects of pollution were necessary results of
prosperity and progress has given way to the
philosophy that the Great Lakes ecosystem
must be managed responsibly and treated
respectfully,
Cooperation on many fronts highlights
the commitment of the people of the United
States and Canada to prevent further degra-
dation and to protect the future of the Great
Lakes. This commitment has been reflected
through the Great Lakes Water Quality Agree-
ment, national programs for environmental
protection and the involvement of govern-
ments, non-government agencies and groups,
researchers, industries, communities and
individuals.
The public's direct actions have influenc-
ed both governments and industry. Together,
citizens from both sides of the border have
provided the impetus for governments to co-
operate and adopt more creative and effective
management solutions to Great Lakes problems.
The concept of an ecosystem approach to
management has become reality from the
experiences of this broad-based Great Lakes
community.
Research conducted in universities
and government agencies is contributing
a substantial body of theory and information
for practical management programs, and a
better understanding of the ecosystem and
its properties. Research continues to look
for solutions to existing and emerging
problems.
The refinement of mass balance and
biomonitoring techniques is an ongoing task.
There is still an urgent need to understand
how toxic substances move through the Great
Lakes ecosystem on Sand, in the air, by water
and through the food web. More information
is needed about less obvious, nonpoint
pollution sources to the Great Lakes, such as
land runoff, iong-range transport of contami-
nants in the atmosphere into the Great Lakes
basin, movement of chemicals in groundwater
and secondary pollution that may occur when
substances combine chemically in air or
water.
Research is required to answer human
health questions, to promote improved
human health and to prevent disease.
Indicators of human and ecosystem health
must be developed and supported by
ecosystem monitoring. The extent to which
the ecosystem is affected by the hormone-like
effects of persistent chlorinated substances
must be determined.
The story of the Great Lakes does
not end here. Although progress has been
steady and the ecosystem has shown signs
of recovery, pollution will continue to be a
major concern in the years to come. A broader
scope of regulation of toxic chemicals may be
necessary as research and monitoring reveal
practices that are harmful. More stringent
controls of waste disposal are already being
applied in many locations. Agricultural
practices are being examined because of
the far-reaching effects of pesticides and
fertilizers. In addition to pollution problems,
better understanding of the living resources
people living around the lakes make
the connection between themselves and the
Great Lakes, they will become increasingly
involved in positive actions. People are indeed
reclaiming, cleaning up and restoring their
watersheds, local shorelines, parks and green
space. Through careful management of tech-
nology and economic development, people
can live within the ecosystem without causing
injury. In return, the lakes and the lands
surrounding them will continue to contribute
to the quality of life for the people of the
region and all living things in the Great Lakes
ecosystem and beyond.
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ALGA (pi. ALGAE) - Simple one-celled or
many-celled micro-organisms capable of carrying
on photosynthesis in aquatic ecosystems.
ANOXIA - The absence of oxygen necessary
for sustaining most life. In aquatic ecosystems,
this refers to the absence of dissolved oxygen in
water.
AREA OF CONCERN - An area recognized by
the International Joint Commission where 1 or
more of 14 beneficial uses are impaired or where
objectives of the Great Lakes Water Quality
Agreement or local environmental standards are
not being achieved.
ATMOSPHERIC DEPOSITION - Pollution
from the atmosphere associated with dry
deposition in the form of dust, wet deposition in
the form of rain and snow, or as a result of vapor
exchanges.
BIOCHEMICAL OXYGEN DEMAND - The
amount of dissolved oxygen required for the
bacterial decomposition of organic waste in water.
BIOMAGNIFICATION - A cumulative
increase in the concentration of a persistent
substance in successively higher trophic levels of
the food chain (i.e., from algae to zooplankton to
fish to birds).
BIOMASS - Total dry weight of all living
organisms in a given area.
BIOMONITORING - The use of organisms to
test the acute toxicity of substances in effluent
discharges as well as the chronic toxicity of low-
level pollutants in the ambient aquatic
environment.
CARCINOGEN - Cancer-causing chemicals,
substances or radiation.
CONSUMPTIVE USE - Permanent removal
of water from a water body. Consumptive use
may be due to evaporation or incorporation of
water into a manufactured product.
DDT - Dichloro-diphenyl-tricriioroethane - a
widely used, very persistent pesticide in the
chlorinated hydrocarbon group, now banned from
production and use in many countries.
DISSOLVED OXYGEN - The amount of
oxygen dissolved in water. See ANOXIA and
BIOCHEMICAL OXYGEN DEMAND.
DIVERSION - Transfer of water from one
watershed to another.
DRAINAGE BASIN - A waterbody and the
land area drained by it.
ECOSYSTEM - The interacting complex of
living organisms and their non-living
environment.
EFFLUENT - Waste waters discharged from
industrial or municipal sewage treatment plants.
EPILIMNION - The warm, upper layer of
water that occurs in a lake during summer strati-
fication.
EROSION - The wearing away and trans-
portation of soils, rocks and dissolved minerals
from the land surface or along shorelines by
rainfall, running water, or wave and current
action.
EUTROPHICATION - The process of fertiliza-
tion that causes high productivity and biomass in
an aquatic ecosystem. Eutrophication can be a
natural process or it can be a cultural process
accelerated by an increase of nutrient loading to a
lake by human activity.
EXOTIC SPECIES - Species that are not
native to the Great Lakes and have been intention-
ally introduced or have inadvertently infiltrated
the system.
FOOD WEB - The process by which
organisms in higher trophic levels gain energy by
consuming organisms at lower trophic levels.
HUMAN HEALTH - The state of complete
physical, mental and social well-being and not
merely the absence of disease or infirmity (World
Health Organization).
HYDROLOGIC CYCLE - The natural cycle of
water on earth, including precipitation as rain and
snow, runoff from land, storage in lakes, streams,
and oceans, and evaporation and transpiration
(from plants) into the atmosphere.
HYPOLIMNION - The cold, dense, lower
layer of water that occurs in a lake during summer
stratification.
LEACHATE - Materials suspended or
dissolved in water and other liquids, usually from
waste sites, which percolate through soils and
rock layers.
MASS BALANCE - An approach to
evaluating the source, transport and fate of conta-
minants entering a water system as well as their
effects on water quality.
MESOTROPHIC - See TROPHIC STATUS
MONOCULTURE - Agriculture that is based
on a single type of crop.
NONPOINT SOURCE - Source of pollution in
which pollutants are discharged over a widespread
area or from a number of small inputs rather than
from distinct, identifiable sources.
NUTRIENT - A chemical that is an essential
raw material for the growth and development of
organisms.
OLIGOTROPHIC - See TROPHIC STATUS
PATHOGENS - Disease-causing agents such
as bacteria, viruses and parasites.
PCBs - polychlorinated biphenyls - A class
of persistent organic chemicals that bioaccumu-
late.
PHOTOSYNTHESIS - A process occurring
in the cells of green plants and some micro-
organisms in which solar energy is transformed
into stored chemical energy.
PHYTOPLANKTON - Minute, microscopic
aquatic plant life (see ALGA).
POINT SOURCE POLLUTION - A source of
pollution that is distinct and identifiable, such as
an outfall pipe from an industrial plant.
PRODUCTIVITY - The conversion of sunlight
and nutrients into plant material through photo-
synthesis, and the subsequent conversion of this
plant material into animal matter.
RESUSPENSION (of sediment) - The
remixing of sediment particles and pollutants
back into the water by storms, currents,
organisms and human activities such as dredging
or shipping.
SEICHE - An oscillation in water level from
one end of a lake to another due to rapid changes
in winds and atmospheric pressure. Most
dramatic after an intense but local weather
disturbance passes over one end of a large lake.
STRATIFICATION (or LAYERING) - The
tendency in deep lakes for distinct layers of water
to form as a result of vertical change in
temperature and therefore in the density of water.
See also EPILIMNION, HYPOLIMNION,
THERMOCLINE
THERMOCLINE - A layer of water in deep
lakes separating the cool hypolimnion (lower
layer) from the warm epilimnion (surface layer).
TOXIC SUBSTANCE - As defined in the
Great Lakes Water Quality Agreement, any
substance that adversely affects the health or
well-being of any living organism.
TROPHIC STATUS - A measure of the
biological productivity in a body of water. Aquatic
ecosystems are characterized as oligotrophic (low
productivity), mesotrophic (medium productivity)
or eutrophic (high productivity).
WIND SET-UP - A local rise in water levels
caused by winds pushing water to one side of a
lake.
ZOOPLANKTON - Minute aquatic animal life.
Metric to Imperial Values
1 metre =
1 kilometre =
1 kilogram =
1 square kilometre =
1 cubic kilometre =
1 litre =
3.28 feet
0.621 miles
2.2 pounds
0.386 square miles
0.24 cubic miles
0.264 U.S. gallons
1 cubic metre/second = 35.31 cubic feet/second
1 tonne = 1.1 short tons
image:
Allardice, D., and S. Thorp. STATE OF THE
LAKES ECOSYSTEM CONFERENCE WORKING
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ECONOMIC AND ENVIRONMENTAL LINKAGES.
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Environmental Protection Agency, 1994.
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HISTORY OF CANADA: THE GREAT LAKES.
Toronto: McClelland and Stewart, 1970.
ALTERNATIVES: PERSPECTIVES ON
SOCIETY, TECHNOLOGY AND ENVIRONMENT.
Special Issue. Saving the Great Lakes. Vol. 13,
No. 3, September/October, 1986.
American Museum of Natural History. THE
ENDURING GREAT LAKES. J. Rousmaniere (ed.).
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Ashworth, William. THE LATE, GREAT LAKES.
New York: Knopf, 1986.
Burns, Noel M. ERIE: THE LAKE THAT
SURVIVED. Totowa, New Jersey: Rowman and
Allanheld Publ., 1985.
Egerton, Frank N. OVERFISHING OR
POLLUTION? CASE HISTORY OF A CONTROVERSY
ON THE GREAT LAKES. Great Lakes Fishery
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Michigan, 1985.
Eichenlaub, Val. WEATHER AND CLIMATE OF
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University of Notre Dame Press, 1979.
Eisenreich, S.J., C.J. Holland and
T.C. Johnson. ATMOSPHERIC POLLUTANTS IN
NATURAL WATER SYSTEMS. Ann Arbor,
Michigan: Ann Arbor Science Publishers, 1980.
Ellis, W.D. LAND OF THE INLAND SEAS:
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Emery, Lee. REVIEW OF FISH SPECIES
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CLJMATOLOGICAL ATLAS. Saulesleja, A. (ed.).
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Chicago, 1991.
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LAKES BASIN COMMISSION FRAMEWORK
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REHABILITATING GREAT LAKES ECOSYSTEMS.
G.R. Francis et al. (eds). Technical Report No. 37,
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Great Lakes Fishery Commission.
STRATEGIC VISION OF THE GREAT LAKES
FISHERY COMMISSION FOR THE DECADE OF
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IMPLEMENTING THE ECOSYSTEM APPROACH IN
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45
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46
RELIEF, DRAINAGE AiMD URBAN AREAS (Page 2)
Canada, map, 1/5,000,000. Ottawa: Surveys and
Mapping Branch, EMR, 1983.
Great Lakes Water Use, map, 1/1,584,000. Burlington:
Inland Waters Directorate (Ontario Region), Environment
Canada, 1980.
International Map of the World, map series, 1/1,000,000,
sheets NL-17, NL-18, NM-15, NM-16. Ottawa: Surveys
and Mapping Branch, EMR, various dates. Internationa]
Map of the World, map series, 1/1,000,000 sheets NK-16,
NK-17, NK-18, NL-15, NL-16, Washington: USGS,
Department of the Interior, various dates.
Karta Mira, map series, 1/2,500,000, sheets 31, 32, 47, 48.
Budapest: National Office of Lands and Mapping,
various dates.
United States, map, 1/2,500,000, east sheet.
Washington: USGS, Department of the Interior, 1972.
GEOLOGY AND MINERAL RESOURCES (Page 6J
Douglas, R.J.W. Geology and Economic Minerals of
Canada, Part B. Ottawa: Geological Survey of Canada,
EMR, 1976.
Geologic Map of North America, 1/1,000,000.
Washington: USGS, Department of the Interior, 1965.
Glacial Map of the United States West of the Rocky
Mountains, 1/1,750,000. New York: Geological Society
of America, 1959.
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University of Illinois Press, 1958.
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from Land Use Activities, Inventory of Land Use and
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Basin, Vol. 1. Windsor: IJC, 1976.
National Atlas of Canada, 4th ed. Ottawa: Surveys and
Mapping Branch, EMR, 1973.
National Atlas of Canada, 5th ed. Ottawa: Surveys and
Mapping Branch, EMR, 1978 and later.
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Department of the Interior, 1970 and later.
Williams, H.R. Department of Geological Sciences,
Brock University, St. Catharines, personal communica-
tion, 1986.
CLIMATE MAPS (Page 8)
Climatic Atlas Climatique - Canada, Map Series 1 -
Temperature and Degree Days. Toronto: AES,
Environment Canada, 1984.
Climatic Atlas of North and Central America, Vol. 1,
Maps of Mean Temperature and Precipitation. Geneva:
World Meteorological Organization, 1979.
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Lakes Basin. Notre Dame: University of Notre Dame
Press, 1979.
Mudrey, D. AES, Environment Canada, Ottawa, personal
communication, 1986.
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Toronto: AES, Environment Canada, 1986.
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THE GREAT LAKES WATER SYSTEM (Page 10)
Great Lakes Diversion and Consumptive Uses.
Windsor: IJC, 1985.
NFB Canada Map, no scale. Montreal: National Film
Board of Canada, 1984.
HISTORICAL MAP (Page 16}
Transparency courtesy of National Archives of Canada,
Ottawa.
LAND USE, FISHERSES AND EROSION (Page 19!
Great Lakes Fishery Commission, 1991.
NOAA - AVHRR Land Cover, Manitoba Centre For
Remote Sensing, 1991.
Stewart, Chris. Canadian Hydrographic Service, personal
communication, 1992.
Tilt, John. Ontario Ministry of Natural Resources,
personal communication, 1992.
WATERBORNE COMMERCE (Page 21)
Coastwise Shipping Statistics 1990. Ottawa: Statistics
Canada, 1992.
International Seaborne Shipping Port Statistics 1990.
Ottawa: Statistics Canada, 1992.
St. Lawrence Seaway Traffic Report for 1990. Navigation
Season. Ottawa St. Lawrence Seaway Authority, 1992.
Waterborne Commerce of the United States, Calendar
Year 1990, Part 3 - Waterways and Harbors Great Lakes.
Washington Corps of Engineers, Department of the
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RECREATION AND SPORTS (Page 23)
Annual Meeting of the Great Lakes Fishery Commission.
Appendix XXXII. Ann Arbor, 1986,
Dean, W.G. (ed.). Economic Atlas of Ontario. Toronto:
University of Toronto Press, 1969.
Illinois, Indiana, Michigan, Minnesota, New York, Ohio,
Pennsylvania, Wisconsin road maps, various scales.
Chicago: Rand McNally & Co., 1986.
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Ontario and the states within the Great Lakes basin.
Ontario road map 1/800,000 and 1/1,600,000. Toronto:
Ontario Ministry of Recreation and Tourism, 1993.
Shore Use and Erosion Work Group, Great Lakes Basin
Framework Study, Appendix R9, Recreational Boating.
Ann Arbor: Great Lakes Basin Commission, 1975.
The National Atlas of the United States. Washington:
USGS, Department of the Interior, 1970 and later.
EMPLOYMENT AND INDUSTRIAL STRUCTURE
(Page 25)
1990 Census of Population, Vol. 1, Characteristics of the
Population, Chap. C, General Social and Economic
Characteristics, Parts 15, 16, 24, 25, 34, 37, 40 and 51.
Washington: Bureau of the Census, U.S. Department of
Commerce, 1991.
1991 Census of Canada, Population, Economic
Characteristics, Ontario. Ottawa: Statistics Canada, 1992.
1991 Census of Canada. Reference Maps. Census
Divisions and Subdivisions. Ottawa: Statistics Canada,
1991.
TRANSPORTATION AND ENERGY MAPS (Page 26)
Generating Station December Installed Capacity.
Toronto: Ontario Hydro, 1985. mimeo.
Handy Railroad Atlas of the United States. Chicago:
Rand McNally & Co., 1982.
Illinois, Indiana, Michigan, Minnesota, New York, Ohio,
Pennsylvania, Wisconsin road maps, various scales.
Chicago: Rand McNally & Co., 1986.
Inventory of Power Plants in the United States 1985.
Washington: Energy Information Administration, U.S.
Department of Energy, 1986.
National Atlas of Canada, 5th ed. Ottawa: Surveys and
Mapping Branch, EMR, 1978 and later.
Ontario, road map, 1/800,000 and 1/1,600,000. Toronto:
Ontario Ministry of Transportation and
Communications, 1986.
Sectional Aeronautical Charts, map series, 1/500,000,
Chicago, Detroit, Green Bay and Lake Huron sheets.
Washington: U.S. Department of Commerce, 1986.
The Gifts of Nature. Toronto: Ontario Hydro, 1979.
National Atlas of the United States. Washington:
United States Geoiogical Survey, Department of the
Interior, 1970 and later.
VIA Rail pamphlets.
DISTRIBUTION OF POPULATION (Page 28)
1980 Census of Population, Vol. 1, Characteristics of the
Population, Chap. C, General Social and Economic
Characteristics, Parts 15, 16, 24, 25, 34, 37, 40 and 51.
Washington: Bureau of the Census, U.S. Department of
Commerce, 1983.
1981 Census of Canada, Population etc., Selected
Characteristics, Ontario. Ottawa: Statistics Canada, 1982.
STATE OF THE LAKES (Page 34)
An Atlas of Contaminants in Eggs of Fish-Eating
Colonial Birds of the Great Lakes (1970-1988 and 1989-
1992), Vol. I and Vol. II. Environment Canada, Canadian
Wildlife Service.
Government of Canada. Toxic Chemicais in the Great
Lakes and Associated Effects: Vol. I and Vol. II. Ottawa:
Supply and Services Canada, 1991.
Neilson, M., et al. State of the Lakes Ecosystem
Conference Working paper: Nutrients: Trends and
System Response. Environment Canada and United
States Environmental Protection Agency, 1994.
ECOREGIONS, DRAINAGE BASINS AND WETLANDS
Ecodistricts of Southern Canada, draft maps,
1/2,000,000, no date.
Ecoregions of the coterminous United States, maps,
1:7,500,000 by James Omernik, Corvallis Environmental
Research Laboratories, U.S. EPA, 1986.
International Reference Group on Great Lakes Pollution
from Land Use Activities, inventory of Land Use and
Land Use Practices in the Canadian Great Lakes Basin,
Vol. 1. Windsor: International Joint Commission, 1977.
Rubec, C. Lands Directorate, Environment Canada,
Ottawa, personal communication, 1986.
Shore Use and Erosion Work Group, Great Lakes Basin
Framework Study, Appendix 10, Power. Ann Arbor:
Great Lakes Basin Commission, 1975.
Wickware, G., Hunter and Associates, Mississauga,
persona! communication, 1987.
PHOTOGRAPHIC CREDITS
Pages 3, 7, 9, 11 (left and right) and 12: D. Cowell,
Geomatics International, Burlington, Ontario.
Pages 5 (left), 29 and 31 (left and right): Great Lakes
Program Office, U.S. EPA, Chicago, Illinois.
Page 5 (right): Harold Murphy, Hamilton Harbour RAP
Office, Burlington, Ontario.
Pages 11 (center), 20 (left), 22 (left) and 40: CCIW,
Burlington, Ontario.
Pages 13, 43: U.S. National Parks Service, Indiana Dunes
National Lakeshore.
Page 14 (left): University of Wisconsin, Extension
Service.
Pages 14 (right), 42: Earth Images Foundation, St.
Catharines, Ontario.
Page 16: National Archives of Canada, NMC-6411,
Ottawa, Ontario.
Page 17: Royal Ontario Museum, Toronto, Ontario.
Page 20 (right): Great Lakes Commission, Ann Arbor,
Michigan.
Page 22 (right): Great Lakes Health Effects Program,
Environmental Health Directorate, Health Canada,
Ottawa, Ontario.
Page 24 (top): Peter J. Schulz, Chicago, Illinois.
Page 24 (bottom): Metropolitan Toronto Convention and
Visitors Association, Toronto, Ontario.
Page 30: Lake Michigan Federation, Chicago, Illinois.
Page 35: J. Lubner, Wisconsin Sea Grant, Milwaukee,
Wisconsin.
Page 39: Little River Enhancement Group, Windsor,
Ontario.
Page 41: P. Bertram, Great Lakes National Program
Office, U.S. EPA, Chicago Illinois.
PRODUCTION
Computerized mapping and map artwork by Geomatics
International and Rawlings Communications, Burlington,
Ontario (5 pages). All other maps by Brock University
Cartography.
Design, layout and artwork for text and front cover by
Agensky and Company Limited, Toronto, Ontario.
Copy editing by Leon Smith, Ajax, Ontario, and Robyn
Packard, Thornhill, Ontario.
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