STATE
OF THE
GREAT LAKES
1995
-------
905R951O3
State of the
Great Lakes
1995
By
The Governments of
the United States of A merica
and
Canada
-------
COOPERATING TO IMPLEMENT THE GREAT LAKES WATER QUALITY AGREEMENT
MISE EN OEUVRE DE L'ACCORD SUR LA QUALITE DE L'EAU DES GRANDS LACS
STATE OF THE GREAT LAKES
Prepared by
Environment Canada U.S. Environmental Protection Agency
For additional copies please contact:
ENVIRONMENT CANADA
867 Lakeshore Road
Burlington, Ontario
Canada
L7R 4A6
ENVIRONNEMENT CANADA
867, rue Lakeshore
Burlington, Ontario
Canada
L7R 4A6
ISBN 0-662-61887-4/Catalogue No. En40-11/35-1995
ENVIRONMENTAL PROTECTION AGENCY
Great Lakes National Program Office
77 West Jackson Blvd,
Chicago, Illinois 60604
U.S.A.
EPA 905-R-95-010 - July, 1995
-------
Table of Contents
Executive Summary i
1. Introduction 1
2. Concepts of Ecosystem Health and Integrity 5
3. Indicators 6
4. Aquatic Community Health 10
4.1 State of Aquatic Community Health 10
4.2 Major Stresses on Aquatic Communities 15
5. Human Health and Wellbeing 25
6. Socio-Economics 28
7. Lake By Lake 33
7.1 Lake Superior 35
7.2 Lake Michigan 38
7.3 Lake Huron 41
7.4 Lake Erie 44
7.5 Lake Ontario 48
7.6 The Connecting Channels 51
8. Management Challenges for the Future 51
STATE OF THE GREAT LAKES - 1995
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Data Sources for Tables and Figures
Table 1: Governments of Canada and the United States. 1995. The Great Lakes: An
Environmental Atlas and Resource Book. (ISBN 0-662-23441-3) 3
Table 2: SOLEC Steering Committee 8/9
Table 3: Koonce, J.F. 1994. Aquatic Community Health of the Great Lakes. (SOLEC
Working Paper - modified) 12
Table 4: SOLEC Steering Committee 20
Table 5: Manno, J. et al. 1994. Effects of Great Lakes Basin Environmental Contaminants
on Human Health. (SOLEC Working Paper) 28
Table 6: Hartig, J.H. and N.L. Law. 1994. Progress in Great Lakes Remedial Action Plans:
Implementing the Ecosystem Approach in Great Lakes Areas of Concern.
(EPA 905-R-24-020) 34
Table 7: same as Table 6 36
Table 8: same as Table 6 39
Table 9: same as Table 6 42
Table 10: same as Table 6 45
Table 11: same as Table 6 49
Table 12: same as Table 6 52
Figure 1: Environmental Conservation Branch, Environment Canada 2
Figure 2: Great Lakes National Program Office, U.S. EPA 6
Figure 3: Great Lakes National Program Office, U.S. EPA 7
Figure 4: Koonce, J.F. 1994. Aquatic Community Health of the Great Lakes. (SOLEC
Working Paper) 13
Figure 5: For data between 1940's-1990: Environment Canada, et al. 1991. Toxic Chemicals
in the Great Lakes and Associated Effects. Vol II, p.588. For data beyond 1991:
Environment Canada. 1995. Great Lakes Fact Sheet - The rise of the Double-
crested Cormorant on the Great Lakes: Winning the War Against Contaminants.
(ISBN 0-662-23280-1) , 13
Figure 6: Environment Canada, et al. 1991. Toxic Chemicals in the Great Lakes and
Associated Effects. Vbl II, p.592 14
Figure 7: Dodge, D. and R. Kavetsky. 1994. Aquatic Habitat and Wetlands of the Great
Lakes. (SOLEC Working Paper) 15
Figure 8: same as Figure 7 17
Figure 9: De Vault, D. et al. 1994. Toxic Contaminants. (SOLEC Working Paper) 21
Figures 10 & 11: same as Figure 9 22
Figure 12: Neilson, M. et al. 1994. Nutrients: Trends and System Response. (SOLEC
Working Paper) 23
Figure 13: same as Figure 12 24
STATE OF THE GREAT LAKES- 1995
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Figure 14: Health and Welfare Canada. 1992. A Vital Link: Health and the Environment in
Canada (ISBN 0-660-14350-X) 26
Figures 15 & 16: Allardice, D. and S. Thorp. 1994. A Changing Great Lakes Economy:
Economic and Environmental Linkages (SOLEC Working Paper) 29
Figure 17: same as Figure 15 30
Figure 18: Mackay, D. et al. 1992. Virtual Elimination of Toxic and Persistent Chemicals
from the Great Lakes: The Role of Mass Balance Models. Report to the IJC's
Virtual Elimination Task Force 37
Figure 19: Great Lakes National Program Office, USEPA 41
Figure 20: Great Lakes Fishery Commission. 1994. Sea Lamprey Management Program:
FY 1997 Program Requirements and Cost Estimates (Draft Working Document) . 44
Figure 21: De Vault, D. et al. 1994. Toxic Contaminants (SOLEC Working Paper) 50
Photo Credits
Zebra mussels on a crayfish: Ontario Ministry of Natural Resources 16
Agriculture in the Great Lakes Basin: Governments of Canada and the United States. 1995.
The Great Lakes: An Environmental Atlas and Resource Book 31
Sand dunes on Lake Michigan: Governments of Canada and the United States. 1995. The
Great Lakes: An Environmental Atlas and Resource Book 54
Acknowledgements
This report was prepared with the help of many individuals who provided input at SOLEC and
subsequently. The Governments wish to acknowledge the particular efforts of the following
people without whom this report could not have been produced:
Environment Canada U. S. Environmental Protection Agency
Harvey Shear Paul Horvatin
Nancy Stadler-Salt Kent Fuller
Violeta Glumac Bob Beltran
Maureen Evans Philip Hoffman
STATE OF THE G R EAT 'LAKES - 1 995
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EXECUTIVE SUMMARY
The purpose of the United States/Canada
Great Lakes Water Quality Agreement
(GLWQA) is the restoration and maintenance
of the chemical, physical and biological
integrity of the waters of the Great Lakes basin
ecosystem. In support of that purpose the
governments of the United States and Canada
sponsored a State of the Lakes Ecosystem
Conference (SOLEC) in October of 1994.
Two objectives of the conference were to
promote better decision-making through
improved availability of information, and to
review current information and find out where
there were data gaps.
Six papers were prepared as background for
the conference: aquatic community health,
human health, habitat, contaminants, nutrients
and the economy. These papers form the
appendices to this report. Discussions at
SOLEC have been incorporated into this report
as appropriate.
The condition of the living components of the
system, including humans, is the ultimate
indicator of its health, reflecting the total effect
of stresses on the system. Measures of the
physical, chemical and biological stresses that
affect the system are equally important in
describing the state of the Lakes and providing
vital information for programs that restore and
protect the integrity of the ecosystem.
For purposes of this report, a small number of
indicators has been chosen. These simple
indicators are intended to summarize the state
of the ecosystem and progress made to date in
addressing the many sources of these
stresses.
Conditions shown by the indicators were rated
in four categories by a panel of technical
experts: poor, mixed/ deteriorating,
mixed/improving and good/restored. The
report draws on information from a variety of
sources.
Overall, the health of the Great Lakes basin
ecosystem is variable. By some measures, the
health is good/restored; such as the aquatic
community in Lake Superior. At the other end
of the spectrum, a number of indicators shows
that some aspects of ecosystem health are
poor such as habitat loss, encroachment and
development in wetlands, and the imbalance of
aquatic communities in Lakes Michigan,
Ontario and the eastern basin of Lake Erie.
Other indicators show conditions between
these extremes.
The state of aquatic communities, including
native species loss and ecosystem imbalance
(these two indicators incorporate some of the
effects of exotic species) and reproductive
impairment of native species shows generally
mixed/improving conditions throughout the
Great Lakes. Lakes Michigan, Ontario and the
eastern basin of Lake Erie rated somewhat
lower, but Lake Superior rated higher because
of fewer numbers of native species lost to
extinction and to healthier lake trout
populations.
Data for the human health indicators do not
exist basin-wide, but air, water, soil and
STATE OF THE GREAT LAKES-1995
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11
sediment contamination, fish consumption
advisories, levels of contaminants in humans
and measures of health status and health
effects were considered as surrogates. The
overall state for human health and
environmental contaminant risks for the Great
Lakes basin is likely mixed or in some cases
improving. This rating reflects the general
decline of concentrations of persistent toxic
substances in all media throughout the Great
Lakes.
Aquatic habitat and wetlands have been given
an overall rating of poor. This is because of
the huge losses of wetlands and other habitats,
in quality as well as quantity. There are a few
bright spots however, for example brook trout
stream habitat in the upper lakes is in relatively
good condition, and there are programs which
exist to protect remaining habitat.
Nutrients such as phosphorus are no longer
the widespread problem they once were in the
early 1970s thanks, in large part, to the efforts
made under the GLWQA. Nutrient stresses
have been given an overall good/restored
rating in the Great Lakes basin. Indicators
such as phosphorus concentrations and
loadings must still be monitored however, to
ensure that elevated nutrient levels do not
throw the ecosystem out of balance again, and
because they can still create local problems.
Loadings of persistent toxic contaminants,
levels of chemical contaminants in fish and
herring gulls, and concentrations in water were
rated as mixed/improving. This rating is based
on the positive response of reductions from
peak levels, but many contaminants still need
further reductions to reach acceptable levels of
risk.
In terms of the economy, infrastructure and
land-use change indicators were rated as poor.
Employment, research and development,
population growth and personal income were
rated as mixed/deteriorating, whereas pollution
prevention, stewardship approach, water
conservation and energy use indicators were
rated as mixed/improving, reflecting a shift in
public attitudes.
A section on each of the five Great Lakes is
also contained in the report. These sections
include more comprehensive information on
each lake's unique conditions/problems, its
Areas of Concern and the progress that is
being made in lakewide restoration, including
the Lakewide Management Plans.
The report concludes with a brief section on
challenges in several areas including the
adequacy of information, the management and
communication of information, the means of
making decisions, improving institutional
arrangements, dealing with biodiversity,
agreeing on endpoints for restoration, focusing
on geographic variability, facing the subtle
effects of toxic substances, connecting
decisions to ecosystem improvements, and the
challenge of sustainability.
STATE OF THE GREAT LAKES-1995
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STATE OF THE GREAT LAKES
1. INTRODUCTION
This report summarizes the state of the
Great Lakes as observed at the end of
1994 by the governments of the United States
and Canada as Parties to the Great Lakes
Water Quality Agreement (GLWQA). Much of
the material in this report, and its six
background papers, was presented and
discussed extensively at a binational
conference, the State of the Lakes Ecosystem
Conference (SOLEC), held in October, 1994.
For that conference, working papers were
prepared on six topic areas: aquatic community
health, human health, habitat, contaminants,
nutrients and the economy. These conference
working papers have been finalized, and are
the background papers to this report.
Additionally, information obtained from the
discussion sessions at the conference has
been incorporated into this report.
It should be recognized that this report
addresses the state of the Lakes, not the state
of programs created to deal with stresses
impacting the system. Program information is
presented in a different series of reports
prepared by the Parties individually, for
example the Canada-Ontario Reports and the
U.S. Reports to Congress on the Great Lakes.
In presenting the State of the Great Lakes
Report, the Parties wish to draw attention to
the substantial improvements that have
occurred in response to cleanup activities and
to the major improvements yet to be achieved.
In developing SOLEC and this report, the
Parties asked some basic questions that are
often asked by decision makers and the
average citizen:
Can we swim, eat the fish that we catch, and
drink the water?
Are the Lakes affecting human health?
Are the Lakes getting better?
Are the fish and birds healthy?
How are endangered species doing?
What are we doing about exotic (non-native)
species?
This report attempts to answer these and
related questions by looking at the state of the
Great Lakes ecosystem and the complex
interactions with the many stressors on the
system.
The ecosystem includes the interacting
components of air, land, water and living
organisms, including humans. The Great
Lakes basin ecosystem is made up of a mosaic
of smaller ecosystems each of which differs
from the others, but none of which is separate
from the others. They contain interacting
physical, chemical and biological components.
Each of these provides habitat for various living
organisms. Within the living organisms are the
genetic resources of the ecosystem, including
genetic diversity that has evolved over
thousands of years. This genetic legacy,
consisting of evolving traits that survived during
varied conditions over millennia, is the basis for
the biodiversity of the ecosystem.
This report views the state of the Great Lakes
ecosystem by looking at the living system,
STATE OF THE GREAT LAKES-1995
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Dull
MINNESOTA '
N
-75 0
PENNSYLVANIA / " - C.._ -ft
300km
Great Lakes Profile
Duluth Chicago
Lake Superior
Lake Michigan
SEA LEVEL
244m
NOTE : 1 The profile is taken along the long axes of the lakes
2. The vertical exaggeration is 2000 times.
3 Lake surface elevations are given above sea level,
and maximum depths are below lake surface level.
Figure 1. The Great Lakes Basin
STATE OF THE GREAT LAKES-1995
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Physical Features and Population
Elevation
Length
Breadth
Average Depth
Maximum Depth
Volume
(feet)
(metres)
(miles)
(km)
(mites)
(km)
(feet)
(metres)
(feet)
(metres)
(cu. miles)
(km3)
Superior
600
183
350
563
160
257
483
147
1,332
406
2,900
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
800
244
393
1,640
Totals
5,439
22,684
AREA:
Water
Land Drainage Area
Total
Shoreline Length
Retention Time
Population: U.S.
Canada
Totals
Outlet
(sq. mi.)
(km2)
(sq. mi.)
(km2)
(sq. mi.)
(km2)
(miles)
(km)
(years)
(1990)
(1991)
31,700
82,100
49,300
127,700
81,000
209,800
2,726
4,385
191
425,548
181,573
607,121
St. Marys
River
22,300
57,800
45,600
118,000
67,900
175,800
1,638
2,633
99
10,057,026
10,057,026
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
River
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
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
10,210
17,017
24,707,075
8,484,2900
33,191,365
Table 1. The Great Lakes Factsheet
STATE OF THE GREAT LAKES-1995
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specifically the health of aquatic communities
and humans. From that perspective it
examines the major stresses which affect the
health of the system. Detail is provided in the
background papers to this report.
As discussed in this report, the state of human
health within the Great Lakes basin is
determined primarily by factors unrelated to
conditions in the Lakes. The stresses related
to the Lakes that can significantly affect human
health are toxic contaminants from the
consumption of fish, and microbial disease
organisms encountered when swimming, or
occasionally found in inadequately treated
drinking water.
In contrast to human health, the health of
aquatic organisms is primarily determined by
the many interacting physical, chemical and
biological factors within the Lakes. This is
because most aquatic organisms obtain all of
their food from within the system and are in
continuous contact with it. Thus, aquatic
community health is the direct result of the
complex conditions and interrelationships
within the Great Lakes ecosystem.
The Setting
By almost any standards, the Laurentian Great
Lakes basin is rich in resources. The Great
Lakes contain one-fifth of all the fresh surface
water on Earth. The basin is blessed with
extensive forests and wilderness areas, rich
agricultural land, hundreds of tributaries and
thousands of smaller lakes, extensive mineral
deposits, and abundant and diverse wildlife.
There are 28 cities with populations of more
than 50,000 in the region, and some 33.2
million people call it home. The basin remains
one of North America's major industrial and
agricultural regions, is linked by a strong
transportation system, and supports a vibrant
and growing tourism and travel sector.
Yet with all its riches, and perhaps because of
them, the Great Lakes basin ecosystem is
under tremendous stress from human
activities. Past and current industrial practices,
nutrient loading, resource extraction,
urbanization, deforestation, introductions of
exotic species, alterations and destruction of
natural areas, contamination of air, water and
soil all these stresses, and more, have
caused the ecosystem to become out of
balance.
As European settlement began 400 years
ago the Great Lakes were far different than
they are today. Compared to their biological
diversity at that time and the virtual absence
of toxic substances and human pathogens,
the Lakes today are severely degraded.
Through the efforts of government and
citizens over the past 25 years, recovery has
been made in many areas. Vast
improvement has been made in control of
nuisance conditions, nutrients, human
disease-causing organisms, and in
conventional pollutants that lead to oxygen
depletion (biochemical oxygen demand).
Also, much progress has been made in
controlling toxic contaminants, although
much remains to be done. In contrast,
although some progress is being made in
protecting and restoring habitat, continuing
losses far exceed gains. In the case of
biological diversity, because each loss of
genetic diversity is permanent, all losses are
additive. Thus the challenge facing Great
Lakes rehabilitation, is to minimize or
eliminate the loss of native species and to
protect the genetic variation within those
species to the greatest extent possible.
STATE OF THE GREAT LAKES-1995
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The long term losses in biodiversity and in
habitat have been severe as reported in the
Aquatic Community Health and Aquatic Habitat
and Wetlands background papers. Although
increasing efforts are being made and losses in
biodiversity and habitat are slowing, the low
point has probably not yet been reached for
both aquatic community health and habitat.
The hope for habitat is that preservation of
habitat essential to high priority ecosystems will
accelerate together with restoration successes.
For biodiversity, its importance is at least
becoming widely recognized and steps are
being taken to protect high priority species and
the ecosystems necessary to support them.
For human health, the low point was reached
in the late 1800s before adequate treatment
was provided for drinking water. In major cities
large numbers of people died due to water
borne diseases. Now the risk of illness from
pathogens is slight and acute risks from toxic
substances have been virtually eliminated,
although the chronic effects of long-term
exposure to low levels is still uncertain.
2. CONCEPTS OF ECOSYSTEM HEALTH
AND INTEGRITY
Concepts of human illness and wellness are
fairly well defined and familiar to most
people. Applying similar concepts to the entire
ecosystem is possible, but not yet well defined,
however, ecosystem health can be measured
to some degree at various levels. For
example: populations can be measured as to
age, size, reproductive success, incidence of
disease, and rate of death. Alternatively,
health of individual organisms can be
measured by biochemical, cellular,
physiological or behavioural characteristics.
One expression of ecosystem health is that of
ecosystem integrity, the term used in the Great
Lakes Water Quality Agreement. The
Agreement's stated purpose is "to restore and
maintain the chemical, physical and biological
integrity of the waters of the Great Lakes Basin
Ecosystem". While not precisely defined,
integrity is understood to include the health of
the constituent populations of the ecosystem,
the biological diversity of the ecological
communities, and the ecosystem's ability to
withstand stress or adapt to it.
Ecosystem integrity includes the health of
living things, the ability of systems to self-
organize, and also the physical and
chemical environment needed to support
good health. This stands in contrast to the
physical, chemical and biological stresses
which act to disrupt integrity and are usually
the result of human activity. Figure 2
illustrates these stresses and their
relationship to the physical, chemical and
biological environment.
An essential concept in dealing with
ecosystem health is that ecosystems and
ecological communities are dynamic and
exist within ranges of condition that reflect
the various disturbances that occur in nature
even without human activities. They exist in
balance with these disturbances and their
composition changes through sequential
states that tend toward stability and
increasingly complex interrelationships.
Mature and relatively stable communities
tend to contain proportionately more
organisms that are longer lived and have
specialized and demanding habitat
requirements. The Great Lakes ecosystem
was in this state before the coming of
European settlers.
STATE OF THE GREAT LAKES-1995
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KEY IMPACTS FROM HABITATS
Phyclnl
. Sunlight
b. Shaltar
c. Raproducthra Suppport
Btoloflleal
d. Contaminant* (thru Btoaccum
a. Preditlon
f. Food
B. Ganattea
h. Pathogani
I. Taate and Odor
j. Aaithatlci
...
1. Toxic Contamination
NutrlantB.and EufrppMcaBnn
2. Phoiphonji
Biological
3. Pathogana
4. Exotic Special
S.Ganatie Lost
6. Population Olaruptlon
Physical
7. Sadbnanta
8. Destruction or Accett Lott
Economic*
Social
Valu**/
Behaviour
liutttutlon*
a
Organizations
Lawa
1
PollclM
Program*
FACTORS
THAT
STIMULATE
OR LIMIT
STRESSORS
Figure 2. Primary Ecosystem Stressors and Effects
3. INDICATORS
Doctors use indicators such as blood
pressure and weight to gauge human
health; economists use indicators such as
interest rates and housing starts to assess the
health of economies. One way to determine
the status of the health of the Great Lakes
ecosystem is to use indicators, which address
a spectrum of conditions ranging from the
health of humans and other living components
of the system to stressors and the activities
that cause them. Ecosystem health indicators
measure ecosystem quality or trends in quality
that are useful to managers and scientists.
An illustration of one such spectrum can be
found in Figure 3.
To determine whether conditions are getting
better or worse it is necessary to identify things
that people can measure and accept as
indicative of the condition of the system.
Further, if these indicators can be agreed upon
as representing acceptable conditions, they
can serve as objectives, targets or criteria to be
achieved through protection or restoration of
various attributes of the system.
Many attempts to develop ecosystem health
indicators have been made or are underway in
STATE OF THE GREAT LAKES-1995
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ACTIVITY MEASURES
(1 &2)
ENVIRONMENTAL MEASURES
(3-7)
Figure 3. Spectrum of Indicators for Contaminants
the U.S., Canada and internationally, including
those outlined in the Aquatic Community
Health background paper.
Ecosystems are inherently complex so that
indicators cannot be completely representative
of all possible conditions. A few very simplified
indicators were developed for SOLEC by a
team of technical experts and are shown in
Table 2. There are many levels of increasing
detail and specificity as subsets of these. The
indicators developed are for the state of
aquatic communities, human health and health
risks, aquatic habitat; and for three categories
of stresses nutrients, persistent toxic
contaminants and economic activity.
Economic activity is considered to be a stress
because the economy of the basin is the basis
for most of the activities that are the source of
stresses affecting the ecosystem. Of course it
is also important to recognize that the economy
also provides the means to control stresses
and restore the system. The indicators
developed for SOLEC and used here are rated
based on information collected for the
background papers. Rating was done in four
broad categories:
poor, (meaning significant negative
impact);
STATE OF THE GREAT LAKES-1995
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8
INDICATORS
STATUS OF INDICATORS
Poor
Mixed/
Deteriorating
Mixed/
Improving
Good/
Restored
|H STATE OF AQUATIC COMMUNITIES H
1 . Native Species Loss (# of native species)
Lake Superior
Lakes Huron, Michigan, Erie & Ontario
2. Ecosystem Imbalance (Lake Trout Dichotomous Key)
Lake Superior
Lake Huron
Lakes Michigan, Erie & Ontario
3. Reproductive Impairment
Effects - all Lakes
Body burdens - alt Lakes
H HUMAN HEALTH AND ENVIRONMENTAL CONTAMINANT RISKS
Overall state
1 . Air/water/soil/sediment contamination
contamination trends (0,, S04, dust)
hospital admission and death rates for respiratory illness (eg.
asthma)
beach closings
infectious diseases related to recreational uses
atmospheric and total radioactivity
2. Fish consumption advisories
contaminant loadings
3. Human contaminant body burdens
4. Measurements of health status/health effects
birth defects and cancer
longevity
children's body weight/development
-
-
'
-
-
'
-
-
'
-
-
'
STATE OF AQUATIC HABITAT AND WETLANDS
1 . Loss in habitat/wetlands quality & quantity
U.S. - Michigan Survey
other states
Ontario - CWS coastal wetlands
- Brook trout stream habitat (Upper Lakes)
- Brook trout stream habitat (Lower Lakes)
2. Encroachment/development basinwide
3. Gains in habitat/wetlands quality & quantity
* areas protected under the North American Wildfowl
Management Plan
net effect
Table 2. Preliminary Indicators of Ecosystem Health
STATE OF THE GREAT LAKES-1995
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INDICATORS
STATUS OF INDICATORS
Poor
Mixed/
Deteriorating
Mixed/
Improving
Good/
Restored
1 NUTRIENT STRESSES I
1 . Total phosphorus loads
targets achieved in 4 of 5 Lakes (1 991 )
2. Total phosphorus intake concentrations
objectives achieved in all Lakes (1991)
3. Lake Erie dissolved oxygen (central basin hypolimnion)
4. Chlorophyll a (as indicator of nuisance algal growth) in
Lower Lakes
I CONTAMINANT STRESSES I
1. Loadings
2. Residue in fish
3. Residue in birds (herring gulls)
4. Body burdens - all Lakes
I ECONOMIC STRESSES AND MITIGATING ACTIVITY i
1 . Employment (manufacturing & other sectors)
2. Infrastructure investment (public & private sectors)
3. Research & development (measures of technological
innovation)
4. Land-use and reuse changes (loss of agricultural land
and urban development)
5. Population growth & stability (compared to other regions)
6. Pollution prevention (expenditures & results -
loadings/emissions/discharges)
7. Personal income (statistics)
8. Adoption of stewardship approach (public & private
sectors)
9. Water conservation (industry & per capita)
10. Energy use (per capita)
Table 2. Preliminary Indicators of Ecosystem Health (continued)
STATE OF THE GREAT LAKES-1995
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10
mixed/deteriorating (meaning that the
impact is less severe, but that the trend
is towards greater impact);
mixed/improving (meaning that the
impact is less severe, but that the trend
is towards less impact); and
good/restored (meaning that the impact
or stress is removed, that the state of
the ecosystem component is restored
to a presently acceptable level).
The condition of the living components of the
system, including humans, is the ultimate
indicator of its health, reflecting the total effect
of stresses on the system. The effects upon
the living system, often expressed as use
impairments, are also the most meaningful
indicators as far as the public is concerned, i.e.
can we swim, fish and drink the water?
Measures of the physical, chemical and
biological stresses that affect the system are
equally important in describing the state of the
Lakes and providing vital information for
programs that restore and protect the integrity
of the ecosystem. An illustration of the
stressor-effects framework is provided in
Figure 2.
4. AQUATIC COMMUNITY HEALTH
4.1 STATE OF AQUATIC COMMUNITY
HEALTH
Compared to their chemical, physical and
biological integrity 400 years ago, the
Great Lakes have changed drastically. The
devastating loss of biological diversity and
subsequent establishment of non-indigenous
(exotic) populations is the most striking
indication of degradation of the Great Lakes.
At least 17 historically important fish species
have become depleted or have been extirpated
(eliminated) from one or more of the Lakes.
Amplifying this loss of species diversity is the
loss of genetic diversity of surviving species.
For example, prior to 1950, Canadian waters of
Lake Superior supported about 200 distinct
stocks of lake trout, including some 20 river
spawning stocks. Many of these stocks are
now extinct, including all of the river spawners.
The loss of genetic diversity of lake trout from
the other Lakes is even more alarming, with
complete extinction of native stocks of lake
trout from Lakes Michigan, Erie and Ontario
and all but one or two remnant stocks in Lake
Huron. Lake trout from other sources are being
stocked into those lakes but little natural
reproduction is ocurring.
Contributing to this loss of diversity has been a
succession of invasions and deliberate
releases of exotic (non-indigenous) aquatic
species. Some 139 non-indigenous aquatic
species have become established in the Great
Lakes since the 1880s. Species that have
established substantial populations include sea
lamprey and the following fish species: alewife;
smelt; gizzard shad; white perch; carp; brown
trout; chinook, coho and pink salmon; rainbow
trout; and round goby. To this list can be
added more recent imports such as the zebra
and quagga mussels, and fish such as ruffe,
rudd, fourspine stickleback and others, and
plant species such as purple loosestrife.
Together, these species have had a dramatic
and cumulative effect on the structure of the
aquatic community in the Great Lakes.
Exotic species may impact native organisms in
a variety of ways ranging from direct predation
or competition for food, to disruption of food
chains or habitat. Whatever the mechanism
of impact, the continuing presence of these
STATE OF THE GREAT LAKES-1995
-------
non-indigenous species poses substantial
problems for the rehabilitation and
maintenance of native species associations.
This loss of biodiversity and the establishment
of non-indigenous populations in the Great
Lakes has been little short of catastrophic. The
history of the Great Lakes and the collapse of
its commercial fisheries offer dramatic
examples of the effects of over-fishing, habitat
loss, pollution and exotic species. Native top
predators, once dominated by lake trout, have
been replaced by hatchery-reared imports.
Table 3 lists the many species of Great Lakes
fish that have been extirpated or are severely
depleted due to human activities. What is not
shown by the table is the fundamental loss of
genetic diversity among surviving species.
U.S. and Canadian stocking programs to
reintroduce lake trout and non-native salmonid
predators to the Great Lakes, have resulted in
the development of highly successful sports
fisheries providing a wide range of species for
anglers. However, they rely heavily on
continued stocking and the stability of fish
communities and fisheries are not predictable
at this time.
Three indicators for measuring the health of
aquatic communities were selected. The first
indicator the number of native species lost
was rated as good/restored for Lake
Superior, and mixed/improving for the other
Lakes. As compared to the other Lakes, fewer
aquatic species have been lost in Lake
Superior because of the lower levels of
development, industry and human population.
Even in the more disturbed Lakes, attempts to
reintroduce depleted species of native predator
fish such as walleye and lake trout have been
partially successful. One must bear in mind
that even though species may be reintroduced,
11
hatchery reared fish do not have the genetic
variability of wild populations.
The second indicator, the Lake Trout
Dichotomous Key, provides a measure of how
balanced the aquatic ecosystem is. The Key is
a complex index based on the scores from a
series of questions relating to lake trout and
the conditions necessary to sustain naturally
reproducing populations. Because of the
dichotomous structure (yes/no), the key does
not necessarily reflect small changes or trends.
The rationale for using lake trout as an
indicator for ecosystem health is based upon
their historical dominance in the Great Lakes
food web and their biological characteristics
this makes them a good surrogate indicator of
changes in aquatic ecosystem health. Further
discussion on this indicator can be found in the
Aquatic Community Health background paper.
Using this indicator, Lake Superior rated as
good/restored, Lake Huron as
mixed/improving, and Lakes Michigan, and
Ontario as poor (Figure 4). For Lake Erie, the
key applies only to the eastern basin of the
Lake which is deep and cool enough to support
lake trout. A similar key based on sustainable
reproduction of the top predator fish in the
remainder of the lake (walleye) would rate a
higher score. While aquatic communities in all
the Lakes have been significantly disturbed
and altered by over-fishing, exotic species,
habitat destruction, nutrient enrichment and
persistent toxic substances, those in Lakes
Michigan and Ontario are the most unstable.
The third indicator for the state of aquatic
communities is reproductive impairment. This
indicator is rated as mixed/improving in all the
Lakes. Exposure to a variety of environmental
STATE OF THE GREAT LAKES-1995
-------
12
Common Name
Lake sturgeon
Lake herring
Lake whitefish
Bloater
Deepwater Cisco
Kiyi
Blackfin cisco
Shortnose cisco
Shortjaw cisco
. Burbot
Deepwater sculpin
Spoonhead sculpin
Emerald shiner
Atlantic salmon
Lake trout
Sauger
Blue pike
Species Name
Acipenser fluvescens
Coregonus artedii
C. clupeaformis
C. hoyi
C. johannae
C. kiyi
C. nigripinnis
C. reighardi
C. zenithicus
Lota lota
Myoxocephalus thompsoni
Cottus rice;
Notropis atherinoides
Salmo salar
Salvelinus namaycush
Stizostedion canadense
S. vitreum glaucum
Lake
Superior
1
NP
NP
NP
1
NP
Lake
Michigan
1
1
3
2
3
1
2
2
NP
2*
Lake
Huron
1
1
3
2
3
2
2
1
2
NP
2*
Lake
Erie
1
1
1
NP
NP
NP
NP
NP
2
2
1
NP
2*
2
3
Lake
Ontario
1
1
2
NP
2
NP
2
2
1
2
2
2*
2*
3
An asterisk (*) indicates stocking programs exist to attempt re-introduction. Status codes are: 1 (Depleted),
2 (Extirpated), and 3 (Extinct). Open cells indicate that status is not depleted relative to historical conditions.
NP indicates that the species was not known to be present historically.
Table 3. Summary of Fish Species Lost or Seriously Diminished in the Great Lakes
stresses including organochlorine compounds
(some widespread, some local) caused
reproductive problems for Great Lakes wildlife,
especially aquatic birds. In fact, various
studies have identified contaminant-associated
effects on 11 species of wildlife in the Great
Lakes. Affected species include fish-eating
mammals (mink and otter), a reptile (snapping
turtle), and fish-eating birds (double-crested
cormorant, black-crowned night heron, bald
eagle, herring and ring-billed gull, and Caspian,
common and Forster's tern). All of these,
except the ring-billed gull, have shown
historical evidence of reproductive impairment
due to contaminants. In the 1950s, 1960s and
early 1970s severe effects were observed and
populations of some aquatic bird species
declined, often because of thinning of egg
shells. Population problems were often
attributable to environmental contaminants, but
in a few cases populations actually increased
during times of high contaminant loadings, for
example the population of ring-billed gulls
increased during this time.
With the reduction in loadings of persistent
toxic contaminants such as PCBs, most of the
fish-eating bird populations have recovered
STATE OF THE GREAT LAKES-1995
-------
13
100-t
80-
UJ
(ฃ.
O
O
W
60
40-
20-
Superior Michigan
Huron
LAKE
Erie
I
Ontario
Figure 4. Lake Trout Dichotomous Key - a score of 100
would indicate optimum and pristine conditions for lake
trout.
and populations of herring gulls, Caspian terns,
black-crowned night herons and double-
crested cormorants have
become re-established in the
Great Lakes (see Figure 5 for
cormorant populations).
However, problems such as birth
defects or failure to reproduce
have continued to occur in a
small percentage of the
population in local areas. For
example low rates of bill defects
and other developmental
abnormalities were seen through
the 1980s in cormorant
populations in areas of high
contamination (toxic "hot spots"
see Figure 6). This suggests
that the birds were still being
exposed to excessive amounts
of PCBs and other
organochlorines from the fish in
these hot spots. It is worth noting
that the "background" frequency
of deformities, as determined from
Western Canada bird populations,
does not differ significantly from
the frequency of deformities in
most other areas of the Great
Lakes.
The reproductive success of
breeding eagles eating Great
Lakes fish remains lower than that
of those nesting inland. However,
recovery of the bald eagle is likely
to be limited by contaminants, by
the absence of appropriate
habitat, and may be limited by
food supply. Over 80% of the
Lake Erie shoreline, and
substantial portions of the
shorelines of Lakes Ontario,
Michigan and Huron are no longer suitable
habitat for the bald eagle because of
35000 -
30000
25000
CO
111
z
JJ- 15000
*
o-
|
1
ป1 ""3 *S
111;
1 11 1
ra para^HHHllill
T 1 T T T T T T T T T T r f T
1
1
i
i
1
r
1
i
1
i
^
1
-------
14
Chicks with bill defects
Figure 6. Geographical Variation in Observation of Bill Defects in Cormorant Chicks 1979-87
agriculture, urban sprawl and other human
disturbances (Figure 7).
Mink and otter have also shown the effects of
exposure to contaminants. Both live in wetland
habitat near the shorelines and consume Great
Lakes fish in their diets. Mink diet consists
mainly of other mammals but is supplemented
by birds, fish and invertebrates. They are one
of the most sensitive mammals to PCBs,
resulting in reproductive problems and death.
Otters may not be as sensitive to these
chemicals, however they may be exposed to
higher levels than mink because their diet
consists mainly of fish. Trends in mink
populations have followed those of fish-eating
birds; the population began to decline in the
mid 1950s and was lowest in the early 1970s
but have recovered somewhat in the 1980s.
Data for otter populations have not shown the
same trends, however they do have a lower
rate of reproduction and therefore, slower
recovery. Mink and otter could serve as
biological indicators of the levels of PCBs in the
shoreline wetlands habitats of the Great Lakes
basin. Thriving populations would indicate the
"virtual elimination" of PCBs from their
environment.
While exposure of the aquatic community to
most known toxic contaminants is declining,
the effect of chronic exposure to low
concentrations of persistent toxic substances
remains uncertain.
STATE OF THE GREAT LAKES-1995
-------
15
HABITAT QUALI
9t Marginal
Good
I
Figure 7. Bald Eagle Nesting Habitat
Over all, the status of aquatic communities is
assessed as mixed/improving. This is based
on recovery resulting from pollution control
since the 1970s.
exotic species, over-fishing and excess
fish stocking (including non-indigenous
species); resulting in imbalances in
aquatic communities and loss of
biodiversity;
4.2 MAJOR STRESSES ON AQUATIC
COMMUNITIES
Great Lakes aquatic communities continue
to be exposed to a multiplicity of physical,
chemical and biological stresses. In terms of
importance, the major stresses on aquatic
communities are:
degradation and loss of tributary and
near shore habitat including coastal
wetlands;
impacts of persistent toxic
contaminants; and
eutrophication in localized areas.
STATE OF THE GREAT LAKES-1995
-------
16
Exotic Species, Excessive Harvest and
Loss of Biodiversity
Although physical and chemical stresses have
contributed to the decline in integrity of Great
Lakes' ecosystems, stresses associated with
biological factors have, in fact, caused much
more severe degradation. In particular, over-
fishing and introduction of exotic species have
had tremendous impacts on aquatic
communities, causing profound changes and
imbalances. This has been discussed in the
section on aquatic community health.
Degradation and Loss of Aquatic Habitat
and Wetlands
The degradation and loss of habitat is a major
stress upon aquatic communities. Habitat in
general constitutes the entire ambient
environment, including physical, chemical and
biological aspects as illustrated in Figure 2.
Upland habitat is of concern as it impacts the
aquatic ecosystem and is addressed from that
perspective.
Wetlands, tributaries, connecting channels,
open lakes and near shore areas of the Great
Lakes each play a vital role in ecosystem
function. The ultimate health of the Great
Lakes ecosystem is strongly dependent on the
health, availability and capacity of these
components. The habitat that is important to
any one species is the portion of the
environment that significantly affects its
survival during each of its life stages. For
purposes of this report, emphasis is on aquatic
habitat directly associated with the Great
Lakes.
Basin-wide data on the quality and quantity of
aquatic habitats are scarce and fragmented,
however the best information exists for
wetlands. A U.S. National Wetlands Inventory
is now being developed which is mapping
wetlands survey information, on the basis of
drainage basins. Environment Canada, in
cooperation with other agencies and groups is
gathering habitat-related information through a
number of programs. Notwithstanding these
initiatives, quantifying habitat status remains
largely descriptive and anecdotal, and there
are no accepted basin-wide classification
systems that integrate all aquatic habitat types
and allow habitat health to be easily measured.
Aquatic habitats function in many important
ways. They play a vital role in nutrient cycling,
uptake and transfer. They are among the most
productive of systems in terms of the growth of
photosynthetic organisms (the assimilation of
energy by plants). Aquatic habitats help to
Photo of zebra mussels on crayfish
STATE OF THE GREAT LAKES-1995
-------
17
maintain water quality and regulate water flows
and levels.They play important, sometimes
very specific roles in the life cycles of
terrestrial, aquatic and avian species, providing
areas for spawning, nesting, rearing, foraging
and sheltering. Aquatic habitats, and the
species that live within them, provide the basis
for a significant proportion of the total
biodiversity of the Great Lakes basin
ecosystem. Among all types of aquatic
habitats, the inshore zone (and its wetlands)
ranks highest in terms of performing these
functions (Figure 8 shows the distribution of
U.S. Great Lakes coastal wetlands).
It is difficult to overestimate the importance of
adequate and diverse aquatic habitat for
healthy aquatic communities it is simply the
most basic building block of ecosystem health.
Without adequate habitat in which to spawn,
breed, nest, stopover, forage and hide, many
species of fish and wildlife cannot survive. In
Lakes Ontario and Michigan, and to a lesser
extent in Huron
and
least partially compensated for these effects by
restructuring and replacing missing tributary-
dependent stocks. Lack of basin-wide data on
the amount and quality of aquatic habitat is a
major barrier to measuring habitat health,
quantifying habitat status, and rehabilitating
aquatic communities. Ensuring the health of
aquatic habitats and wetlands is a priority
concern for ecosystem health in the basin, and
will require a greater share of resources than it
has been receiving to date.
Stress on aquatic community health caused by
loss and degradation of physical habitat is
pervasive throughout the Great Lakes
ecosystem, but is most notable in the near
shore and wetland areas. These habitats exist
in a relatively narrow band along the shores
and it is these highly diverse and biologically
complex areas that contain unique
assemblages of organisms and provide food
and shelter for many species during sensitive
reproductive and juvenile stages. The highly
Superior,
stocking of
predators
obscures the
effects of
degraded
habitat. The lack
of adequate
spawning areas,
for example,
becomes less
obvious at least
in terms of fish
production. In
highly polluted
areas of the
Great Lakes, fish
communities
may have at
Distribution of Approximately 300,000 acres
(120,000 ha)
Figure 8. Distribution of U. S. Great Lakes Coastal Wetlands
STATE OF THE GREAT LAKES-1995
-------
18
productive shallow water habitats are
particularly crucial to forage fish and wading
birds.
In pelagic (deep water) areas the loss of
habitat quality is not well documented, but
sedimentation is probably impacting the
benthic community and may be impairing some
spawning areas. Anoxia in the hypolimnion
(colder bottom layer) of the central basin of
Lake Erie is still affecting the benthic
community there, although nutrient control has
reduced the area affected. For Lake Erie some
anoxia may be a naturally occurring
phenomenon. In shallower areas such as
western Lake Erie and other near shore areas,
the benthic (bottom dwellers) communities
were severely impacted by pollutants and
sedimentation. Most of these areas are
showing signs of recovery.
In the shallow littoral zone, often characterized
by the presence of rooted aquatic vegetation,
aquatic communities have suffered large
losses in area and in the quality of the areas
that remain. Destruction and degradation of
the nearshore habitat has been caused by a
variety of factors, but primarily by draining,
sedimentation, filling, and invasion by exotic
species such as carp. Similarly in the
tributaries and associated wetlands, aquatic
communities have been degraded or lost due
to those same stresses. Further loss of habitat
has been caused not by actual destruction, but
by isolation from lakes by dams and dykes.
Lastly, degradation has occurred because of
changes in timing and duration of inundation
and drying because of changes in river flows
and regulation of lake levels. These changes
destroy aquatic communities that have evolved
with cycles established over many centuries.
The quality of chemical habitat has been
degraded first by oxygen depletion in harbours
and then by excess nutrients and widespread
eutrophication. This has been followed by
contamination by bioaccumulative persistent
toxic substances as well as by non-persistent
toxic substances.
The first indicator selected for the state of
aquatic habitat and wetlands is the loss of
habitat (both in terms of quality and quantity),
and was given a rating of poor. Loss of
wetlands in the U.S., loss of coastal wetlands
in Ontario, and loss of brook trout habitat in
tributaries to the Lower Lakes were all
considered evidence of poor conditions.
Wetland losses, in particular, have been
significant across the basin. Studies show that
in some areas up to 100% of coastal wetlands
in Lakes Ontario, Erie, Michigan and St. Clair
have been lost to development. Losses of total
wetlands (including both coastal and inland
wetlands) have been staggering. Sixty percent
of the original wetlands in the Great Lakes
basin states have been lost since the 1780s; in
Ontario, south of the Precambrian Shield,
wetland losses have been estimated to be as
high as 80%. While losses continue, current
rates of loss are unknown, as are rates of
impairment. In many cases, wetlands may still
appear to exist but may be functionally
degraded through siltation, nearby
development, the introduction of foreign plants
and animals, and other stresses. Few data
exist on the magnitude of losses for other
critical habitats such as rocky shoals, sheltered
bays, estuaries and tributaries.
In contrast, the indicator for loss of brook trout
stream habitat in the Upper Lakes was rated as
good/restored. Fewer cold water streams have
STATE OF THE GREAT LAKES-1995
-------
19
been lost and degraded in the Upper Lakes
basins because of the lower degree of
urbanization and human disturbance.
A second indicator encroachment and
development of wetlands was also rated as
poor. This reflects the continuing loss and
degradation of wetlands basin-wide due to
urban development, recreational uses,
agriculture and other forms of encroachment.
The third indicator selected considered gains
in habitat and wetlands through protection,
enhancement and restoration efforts. There
are various international, national and
state/provincial policies and programs for
habitat/wetlands protection, some of which
rate quite high in results. However, the net
effect of protection, enhancement and
restoration is considered to be poor since
programs are not keeping up with habitat
losses. An example of a program producing
good results is the North American Waterfowl
Management Plan which has resulted in the
protection of over 17,500 hectares of
wetlands in the basin.
Persistent Toxic Substances
Persistent toxic contaminants have had an
impact on fish and wildlife species in the
basin as noted in the aquatic community
health section. Observed effects include
alteration of biochemical function,
pathological abnormalities, tumours, and
development and reproductive abnormalities.
Recent studies have suggested that the
estrogenic effects of some organochlorines
are implicated in developmental abnormalities
in wildlife species. A possible consequence
of the effects is a decrease in fitness of
populations. In fish, however, it is difficult to
link cause (i.e. exposure to one or more toxic
contaminants) to effects. Laboratory studies
and field observations suggest that tumours
in Great Lakes bullheads and suckers (both
bottom feeders) may be caused by
contaminated sediments. In general,
however, the effects of exposure to low levels
of contaminants are less clear for fish
populations than for wildlife in the basin. For
a list of priority contaminants see Table 4. To
measure the impact of persistent toxic
contaminant stressors, three indicators were
selected: loadings of persistent toxic
contaminants, levels of chemical
contaminants in fish and levels in herring
gulls. Each of these indicators is considered
as mixed/improving. Levels of persistent
toxic contaminants have been reduced
substantially since 1970. As to reductions in
loadings of persistent toxic substances,
detailed figures are not available basin-wide,
but the ecosystem response over time can
be seen in declining contaminant
concentrations in waters, sediments, fish and
wildlife as illustrated in Figures 9, 10 and 11.
Levels of organochlorine contaminants in the
tissues of top predator and forage fish
declined significantly from the late 1970s to
mid 1980s but have shown a slower rate of
decline more recently (Figure 10). Despite
this overall trend, during the late 1980s, in
some areas, levels of some of these
contaminants increased in some fish. On the
other hand, from the late 1970s to the mid
1980s, concentrations of heavy metals
showed little change. Regardless of the
general downward trend, levels of persistent
toxic contaminants in certain fish species in
some areas continue to be high enough to
restrict consumption by humans.
STATE OF THE GREAT LAKES-1995
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20
CHEMICAL
Aldrin
Benzo(a)pyrene
Chlordane
Copper
DDT and metabolites
Dieldrin
Furan
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Alkylated lead
a Hexachlorocyclohexane
P Hexachlorocyclohexane
Mercury
Mirex
Octachlorostyrene
PCBs
2,3,7,8-TCDD (a dioxin)
Toxaphene
REFERENCE
GLWQA
Annex 1
GLWQI
LaMPs
critical
pollutants
Pollution
Prevention
IJC list of 1 1
critical
pollutants
Lake
Superior
Priority
Substances
COA
Tier t list
COA
Tier II
list
GLWQA=Great Lakes Water Quality Agreement GLWQI-Great Lakes Water Quality Initiative
LaMP-Lakewide Management Plan IJC=lnternational Joint Commission COA=Canada-Ontario Agreement
7a6/e 4. Priority Contaminants of the Great Lakes
One possible cause of these continuing high
levels is that contaminant concentrations in
fish are influenced by changes in food that
varies in availability and contaminant content.
As a result, changes in contaminant levels in
fish may be influenced by shifts in feeding
behaviour by the fish or elsewhere in the food
web.
Adult herring gulls, as permanent residents of
the Great Lakes basin, offer a monitoring
opportunity to detect regional variability in
STATE OF THE GREAT LAKES -1995
-------
21
Lake Superior Lake Michigan Lake Ontario
1990
1980
1960
1940
1920
1900
1880
1860
1840
1820
18001
0
100 200 300 0
100 200 300 0
100 200 300
Figure 9. Lead (Pb) and Mercury (Hg) in Dated Sediment Cores
contaminant stress that is not complicated by
migratory patterns characteristic of other fish-
eating bird species. Monitoring of
reproductive successes at various sites first
began on Lakes Erie and Ontario in the early
1970s and in 1975 for Lakes Superior and
Huron by the Canadian Wildlife Service
(CWS). Depressed productivity levels of
herring gulls have not been found at most of
the sites on Lakes Huron and Superior since
1975. However, on the more populated and
contaminated lakes, reproductive success
was low in the early 1970s and has improved
since. From 1974 onward, organochlorine
residues in herring gull eggs have generally
declined from higher levels in the early 1970s
(Figure 11).
Chemical residues in herring gull eggs have
been monitored since 1974. Organochlorines,
including PCBs, DDT/DDE, mirex, dieldrin
and HCB, have shown a statistically
significant decrease at more than 80% of the
sites sampled. Chemicals monitored later in
the program, such as oxy-chlordane, photo-
mirex, and 2,3,7,8-TCDD, have also shown
significant decreases. The greatest decrease
observed occurred between 1974 and 1981;
since then the rate of decrease has slowed
and levelled off. In 1991-1992, increases
in the level of certain contaminants have
been noted in some locations. The reasons
for this apparent increase are not known, and
may be linked to changes in diet due to
changes in the food web.
Over all, contaminant levels have shown
good response to control programs although
the rate of response has slowed. However, it
is important to recognize that although large
STATE OF THE GREAT LAKES-1995
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22
BSttBS
Drnt* Source: Dซpซrtm*nt of FIซh*rtปB and Ocปซnซ
US environmental Protection Agency'NiOonat Btotofllcel Surv.y
PCB levels (pg/g wet weighttS.E.) in aged 4+whole trout, 1970-1992.
PCB tovcto (pa/a w*l wปlghtฑS.D.) In whoto lake Mul (cempoM**. 600-700 mm T.L.), 1BTT-1M2.
Late* Erto { US Dcta) ttbtttncd wltft Waltoy*.
F/'gure -/O. Tote/ PCB Levels fag/g wet weight) in Lake Trout 1970-1992
Figure 11. PCB Levels (ug/g wet weight) in Herring Gull Eggs 1974-1993
STATE OF THE GREAT LAKES - 1995
-------
23
Data Sourc* EnwrxvnirtaJ Conaปrvซfcon Branch, Envwnnnw* Canada
Great LaJtM National Program Offkป, US EPA
Figure 12. Spring Mean Total Phosphorus Trends for Open Lake 1971-1992
percentage reductions have been achieved in
comparison to peak levels, for many
contaminants, an additional ten fold reduction
is needed to reach acceptable levels of risk.
Also, as more is learned about long term
exposure and endocrine effects, even lower
levels may be required to reach acceptable
risk.
Eutrophication
Although eutrophication is no longer a problem
in the Great Lakes on a lake-wide basis, it
continues to occur in local areas and has a
significant impact on aquatic communities.
This is particularly of concern in tributaries,
bays, coastal marshes and inland wetlands.
Nutrient enrichment causes excess growth of
algae, the decomposition of which depletes the
oxygen needed to sustain other forms of
aquatic life. Algae can also limit penetration of
sunlight to the extent that rooted plants are
affected.
Three indicators were rated as good/restored.
The first indicator is total phosphorus loadings,
where GLWQA targets have been achieved in
Lakes Superior, Huron and Michigan, and in
Lakes Erie and Ontario are at or near their
target loads. The second indicator is total
phosphorus concentrations in open water;
GLWQA objectives were achieved by 1990 in
all lakes, then fluctuated near the limit for Lake
Erie during 1991-92 (see Figure 12). The third
"good/restored" rating was given to an indicator
STATE OF THE GREAT LAKES-1995
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24
F/gure 73. Spring Mean Nitrate-plus-Nitrite Trends for Open Lake 1968-1992
measuring the levels of chlorophyll a in the
Lower Lakes, that is a surrogate for the
productivity of the system (the amount of algae
growth). The low level of chlorophyll a found
today is consistent with the GLWQA objective
for these Lakes of "reduction in the present
level of algal biomass to a level below that of a
nuisance condition". However eutrophication
and/or undesirable algae continue to present
problems in 21 of the 42 Areas of Concern
(AOCs).
The fourth indicator levels of dissolved
oxygen in Lake Erie's bottom waters was
considered mixed/improving. Oxygen levels in
Lake Erie's bottom waters are much better
than they were twenty years ago.
Notwithstanding this, and despite phosphorus
loading reductions, periods of anoxia (lack of
oxygen) were still occurring from 1987 to 1991
in the late summer in some areas of the central
basin. This continued anoxia may be related to
the continuing release of phosphorus from old
bottom sediments, or, it may be that
intermittent anoxia is an inherent property of
Lake Erie's central basin.
Another nutrient that is monitored in the Great
Lakes is nitrate-plus-nitrite. Levels have been
increasing over the past two decades,
especially in Lake Ontario (Figure 13). Major
sources of nitrogen to the Lakes include
agricultural runnoff, municipal sewage
treatment plants and atmospheric deposition.
STATE OF THE GREAT LAKES-1995
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25
The concentrations currently found in open
lake waters do not create a public health
concern because they are at least 20 times
lower that the guideline for drinking water
(10mg/L), however, monitoring will continue as
warranted.
5. HUMAN HEALTH AND WELLBEING
The overall rating for environmental
contaminant stresses from the Great
Lakes on human health in the basin is
mixed/improving. Because limited data exist to
measure impacts of contaminant stresses on
humans in the Great Lakes over time, the
levels of contaminants in the ambient
environment and in fish and wildlife are used
as a surrogate. Based on this, the stress from
toxic contaminants on human health was rated
as mixed or in some cases improving. This
rating reflects the general decline of
concentrations of persistent toxic substances in
all media including fish throughout the Great
Lakes, and the fact that the major route of
human exposure to Great Lakes contaminants
is through fish consumption.
Direct indicators of human health include the
incidence of birth defects and cancer;
longevity; children's body weight and
development; and incidence of infectious
diseases related to water sports and drinking
water. Indirect measures include beach
closures and fish consumption advisories.
Although basin-wide data for these measures
are not available at this time, the 1994 Report
Progress in Great Lakes Remedial Action
Plans: Implementing the Ecosystem Approach
in Great Lakes Areas of Concern did show 35
of the 42 AOCs around the Great Lakes have
fish consumption advisories. The report also
showed 24 of the 42 AOCs have beach
closures or recreational body contact
restrictions.
Because human health reflects the effects of
stresses of many kinds from many sources,
direct measurement of the effect of any one
stress or category of stress is extremely
difficult and costly. As a result, most indicators
of human health are expressed in terms of
health risks attributable to various stresses. A
number of factors make it difficult to establish
a link between environmental contaminants
and human health effects. These include:
the continuous nature of exposure over
many years to low levels of
contaminants;
exposure to mixtures rather than
individual compounds;
the large number (and in some cases
poor definition) of health effect
endpoints to be examined, and the
difficulty of measuring some effects;
experimental design problems,
including the inability, in some cases, to
obtain adequate sample sizes and
measurements that are suitably
sensitive and specific to detect
changes;
dose-response questions;
accurate exposure assessment; and
confounding variables that may hinder
research studies.
Environmental contaminants are only one
category of variables that affect human health.
Other variables include nutrition, adequate
shelter, genetic make up, exposure to bacterial
or viral disease agents, lifestyle factors such as
smoking, drinking and fitness, social well-being
and others.
STATE OF THE GREAT LAKES-1995
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26
A number of indicators can be used to
indirectly measure environmental contaminant
stresses on humans in the Great Lakes.
These include measures of water quality; air
quality; atmospheric and total radioactivity.
However, even with measures of stress and
exposure, information on differences among
basin, national and global levels is limited. In
order to assess better the impacts of
environmental stresses on human health,
better trend data over time are needed on body
burdens, exposures and potential health
effects.
Hundreds of chemicals have been identified as
being present in the Great Lakes ecosystem.
Of these, the IJC has identified 11 as critical
pollutants based on: 1) presence in the Great
Lakes environment; 2) degree of toxicity; 3)
persistence; and 4) ability to bioconcentrate
and bioaccumulate. The 11 substances are
listed in Table 4 together with several others
identified for priority consideration. While
these have been recommended for
priority consideration, there are _
numerous other substances which
must also be considered because
of their known or suspected impact
on the ecosystem and human
health.
There are a number of pathways by
which humans in the Great Lakes
basin can be exposed to persistent
toxic contaminants. The major
route of human exposure to PCBs,
dioxins, furans, organochlorine
pesticides and certain heavy
metals is food consumption,
particularly consumption of
contaminated fish. Food is
believed to contribute between 40
to nearly 100% of total intake for
many of these substances. Studies
of fish eaters in the Great Lakes
basin have shown a correlation
between sport-caught fish
160
140
120
consumption and body burden of PCBs and
DDE in blood and serum. Other routes of
exposure include drinking water, breathing
contaminated air, and dermal (skin) exposure.
For contaminants other than chemicals, such
as microbes, the major routes of exposure for
humans are through poorly treated drinking
water and recreational activities such as
swimming. An example of microbial problems
is the protozoan Cryptosporidium. Its presence
in drinking water caused over one hundred
fatalities and 400,000 people to become ill in
the Milwaukee area in 1993.
Human populations in the Great Lakes basin,
as with those living elsewhere, are exposed to
many toxic pollutants present in the
environment. Those of particular concern in
relation to the GLWQA include dioxins and
furans, organochlorine pesticides and their
byproducts such as hexachlorobenzene,
combustion byproducts such as polycyclic
aromatic hydrocarbons (PAHs), and certain
1967 1970 1973 1982 1986
Year
DDT
PCB
Figure 14. DDT and PCBs in Breast Milk (Canada)
STATE OF THE GREAT LAKES-1995
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27
metals and their compounds such as cadmium,
lead, and mercury. Figure 14 shows trends of
PCBs and DDT in breast milk. Other
contaminants include radioactive elements
such as radon and air contaminants such as
ground level ozone and smog.
While there is a large volume of scientific
evidence to show that these agents are
harmful, it is not certain how much harm they
are causing to the inhabitants of the Great
Lakes basin. There are several reasons for
this uncertainty. One is the scarcity of suitable
health statistics (indicators) to show the spatial
and temporal trends of the state of health of
various Great Lakes populations relative to that
of people living elsewhere. Suitable data are
lacking, for example, on the "normal" growth
and physical and mental development of
children; on the general state of health and
longevity of people living in various regions; on
the number of people seeking treatment for
infectious diseases caused by contaminated
recreational or drinking water; and on the
number of people admitted to hospital for
effects caused by exposure to chemical
environmental contaminants. Reliable
statistics on the occurrence of birth defects or
cancers are lacking for some regions of the
basin. It is also difficult to ascertain exposure
(i.e. to what kinds of contaminants and to what
levels people are exposed). A large number of
contaminants occur at low concentrations,
some of which may gradually accumulate in
the body; others are excreted without leaving a
trace, although they may have done some
damage.
In the past, health researchers and public
policy-makers have tended to focus on
dramatic episodes accompanied by obvious
health effects such as massive spills of
chemicals, or smog episodes, and on the most
serious kinds of health effects such as cancer.
Recent scientific evidence, however, based
mostly on observations in animals, raises
concerns that exposure to low levels of certain
contaminants may cause subtle reproductive,
developmental and physiological effects that
may go easily unnoticed, but which in the long
term may lead to serious cumulative damage.
This includes such effects as immunotoxicity,
neurotoxicity, hormone mimicry, subtle pre-
and postnatal developmental effects, and
decreased fertility. In trying to assess the
effects of contaminants on human health, the
U.S. and Canadian governments have moved
to use a "weight of evidence" approach which
relies on information from many sources,
including data on animals as well as humans.
This allows educated guesses to be made and
then to be tested through appropriate long-term
medical and scientific studies.
The health of the human population of the
basin has improved dramatically since the early
pioneering days, as measured by longevity, or
in the incidence of fatal or crippling infectious
diseases such as poliomyelitis or typhoid fever.
However, much of that improvement is the
result of improvemehtsnn sanitation, vaccines
and drinking water disinfection. On the other
hand, there have been slow, but steady
increases in the incidence of certain cancers
and respiratory illnesses, and we do not know
whether, or to what extent, the many
environmental contaminants contribute to
these and other human diseases. In addition,
there are indications that certain kinds of
chemical contaminants may interfere with the
reproduction and development of animals and
humans. These and other signs of possible
subtle environmental contaminants on human
health need further investigation.
Comparing the Great Lakes basin with other
areas, available information indicates that
levels of priority contaminants such as PCBs,
dioxins and furans in human tissues of Great
Lakes residents are similar to levels found in
STATE OF THE GREAT LAKES-1995
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28
AreaTYr
Michigan (76)
Michigan ('77-78)
Michigan ('82)
N, Carolina ('78-84)
Binghamton, N.Y. ('85-'87)
St. Lawrence, N.Y, ('90}
U.S. (79)
U.S. (79-'80)
Number of
samples
95
1057
138
617
7
57
50
102
% Positive
100
100
100
94
pooled
2
100
Mean* (ppm)
0.82 (med)*
1.5
0.74 (med)*
1,5 (med)*
0.15
0.405
>1 (med)*
0.97
Range (ppm)
0.1-3.3
0,3-5.1
0.3-14.8
0.25->1.0
>1-3
0.08-4,4
+ Arithmetic mean *med=median
other hand, the
strength of the
economy
provides
resources
potential
restore
maintain
the
and
to
and
the
Table 5. Mean Concentration of PCBs in Breast Milk Throughout the U. S.
and St. Lawrence
human populations elsewhere, suggesting that
exposures are also similar. Table 5 shows a
comparison of PCBs in breast milk between
the Continental U.S. and the Great Lakes
region. Although the contaminant levels in
Great Lakes residents are comparable to other
areas, this does not mean that they are
acceptable.
6.0 SOCIO-ECONOMICS
Growth of the North American economy
followed the arrival of European people
with their intensive agriculture, resource
exploitation, urbanization and exotic fauna and
flora. The result of this growth has been a
significant disruption of the ecosystem.
Conversion of native forests and prairies to
agriculture had an immense impact on the
native fauna and flora throughout the region.
Urbanization with its intensive land uses and
transportation facilities provided further
impacts. Today's continuing urban sprawl
adds to the stress on the ecosystem. On the
integrity of the
ecosystem.
Historically the
Great Lakes and
their tributaries
provided access
and trans-
portation for
development of a
major portion of
the inland area
of the North
American
continent. The agricultural and mineral wealth
of the region then fuelled the development of
an economy that included a major
concentration of iron and steel production and
metal fabricating. This in turn spawned a large
cluster of durable goods manufacturing.
Machinery, transportation and other
equipment, appliances, construction materials
and motor vehicles became manufacturing
mainstays. Industries of the Great Lakes
region today continue to rely on water. Water
use in manufacturing is concentrated in 5
sectors: steel production, food processing,
petroleum refining , chemicals and the paper
industry. Although industrial water use is now
declining, water from the Great Lakes supplies
more than three-quarters of the industrial
demand in the basin.
The Great Lakes basin represents nearly 11 %
of total employment and 15% of manufacturing
employment for the two nations. However, the
economy of the region has slowed in recent
decades and has been shifting away from its
historic concentration in manufacturing. From
STATE OF THE GREAT LAKES-1995
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29
1970 to 1990 the basin lost nearly
21% of its manufacturing jobs
(Figure 15). In contrast, total
manufacturing jobs throughout
Canada increased by 22% and held
nearly steady throughout the U.S.
with a 0.3% gain. This has caused a
dramatic redistribution of
employment within the basin. During
this same time period service sector
jobs have increased by just over
100% with more than 2 million jobs
added in the basin.
The regional economy is strongly
integrated and is the largest such
binational relationship in the world.
Trade between Canada and the eight
Great Lakes States in 1992 was
valued at $148 billion Can. ($106
billion U.S.) see Figure 16, or
56.2% of the U.S. Canada total. Three-fifths
of this was in autos, auto parts and engines.
On a national scale, Canada accounts for one-
fifth of U.S. trade and in turn the U.S. receives
two-thirds of Canada's exports.
70 '80 '90
70 '80 '90
YEAR
70 '80 '90
|| Manufacturing Employment
H| Service Employment
| | Total Employment
Figure 15. Great Lakes Basin Employment
Population within the region is distributed
unevenly and is concentrated in metropolitan
areas. Approximately three-quarters of the
population is concentrated in the Lake
Michigan and Lake Erie basins. Another
one-fifth is in the Lake Ontario basin and
the remaining tenth in the Huron and
Superior basins (Figure
17).
Canada - Great Lakes State Trade
1992
Wl TOTALS
Canada Imports
Canada Exports
Figure 16. Canada-Great Lakes States Trade for 1986
The majority of the basin
population is located within
the 17 largest metropolitan
areas most of which are on
the shores of the Lakes.
Six areas contain 75% of
Canada's Great Lakes
population and 11 contain
81% of the U.S. basin
population. Total
population of the Great
Lakes basin is
approximately 33 million,
although estimates can vary
STATE OF THE GREAT LAKES-1995
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30
depending on how much of the Chicago
metropolitan area population is included based
upon current or historic watershed boundaries.
Population growth in the recent decades has
slowed. While the combined population of the
U.S. and Canada grew by 22% from 1970 to
1990, rising from 225 million to 275 million, the
binational population of the Great Lakes basin
grew by less than 1%. Ontario, with more than
a third of Canada's population, has been
gaining population nearly twice as fast as the
Great Lakes states but its rate of growth is also
slowing. By 1990, the Great Lakes states'
population increased by only 1.7% since 1970
whereas Ontario's 1991 population increased
by 31% from 1971. However, within this
relatively static picture, substantial
redistribution of population is taking place
causing significant impact on the ecosystem.
While both central city and rural areas have
been losing population, suburban areas have
been growing rapidly, often drawn to "coastal
amenities" along the shores of the Lakes.
Industry and service business development
have been decentralizing from built-up city
locales to suburban-exurban fringe areas and
connecting corridors between metropolitan
areas. Land and water availability, lower wage
scales, transportation access, proximity to new
residential markets and other cost/service
factors are propelling this kind of sprawl.
Figure 17. Population of the Great Lakes Basins
STATE OF THE GREAT LAKES-1995
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31
The most significant population and related
development issue in the Great Lakes basin
and surrounding region is the continuing
growth of major metropolitan areas and the
virtually uncontrolled sprawl of lower density
residential and other development. The
detrimental consequences of these trends are
well known. Increased generation of water and
air pollution, higher transportation and
residential energy use, increasing
encroachment on agricultural lands and natural
areas, higher housing costs, disinvestment in
older communities and social disruption and
burdensome infrastructure requirements
portend a more difficult, if not unsustainable,
future for the Great Lakes basin ecosystem.
However, the escalating cost of extending
utilities and other basic urban services to these
lower density regions may ultimately slow the
process and stimulate a more sustainable
pattern. One of the challenges in attaining
more sustainable forms of development is the
lack of accurate and visible cost accounting
showing the real cost to society of allowing
suburban sprawl. A new land stewardship
ethic would rely more on intensification of
development within prescribed boundaries
and existing infrastructure capacity as is
done in some other countries.
Agriculture in the Great Lakes basin is both
diverse and productive, and is a major part
of the overall economy not only of the
basin but also of the two nations. With
respect to value and volume, dairy, cash
grain and livestock sales are the region's
agricultural mainstays. In addition, the
region has a wealth of specialty crops,
attributable to small unique climatic zones.
Since farming depends on the vagaries of
weather, the Great Lakes basin agricultural
productivity could be jeopardized if
significant climate change occurs. Other
issues of concern for the region include the use
of chemicals and soil erosion. More than 57
million tonnes (63 million tons) of soil erode
annually in the U.S. portion of the Great Lakes
basin. This results in reduced agricultural
productivity (lower yields), increased fertilizer
use, and also causes increased sedimentation
of streams and tributaries.
On a positive note, the Great Lakes basin, with
more than 260,000 square kilometres (100,000
square miles) of navigable water and 16,926
kilometres (10,579 miles) of shoreline, anchors
an important and growing coastal recreation
industry. The recreational boating industry is
represented by boat manufacturers and
retailers, marina operators, marine business
suppliers as well as millions of recreational
boaters and anglers. For the Great Lakes it is
estimated that between 900,000 and 1 million
U.S. and Canadian boats operate each year
with a direct spending impact of more than
$2.8 billion Can. ($2 billion U.S.). With a
strong connection to boating, Great Lakes
Agriculture in the Great Lakes Basin
STATE OF THE GREAT LAKES-1995
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32
sport fishing is a major part of regional fishing
activity. U.S. federal surveys projected 2.55
million U.S. anglers fished in the Great Lakes
in 1991 and had total trip-related and
equipment sales expenditures of $1.86 billion
Can. ($1.33 billion U.S.). Expenditures per
angler were calculated at about $700 Can.
($500 U.S.) for the year.
Economic activity produces both stresses on
the ecosystem and the means to address or
mitigate them, so economic indicators should
be viewed from that perspective.
this time period grew at 15%, while
employment in the Canadian side of the basin
grew by only 6%. Research and development
are measures of technological innovation, an
area that has recently faltered in the
manufacturing industry. However, the
emergence of a substantial "environmental
industry" sector including resource
conservation, pollution remediation and
reduction technology and other goods and
services intended to help the economy reduce
its negative impact on the physical and social
environment, may soon see this indicator
change to a mixed/improving rating.
Ten economic indicators were selected. Two
of these were rated as poor- infrastructure
investment and loss of agricultural land and
urban development. Public infrastructure
includes roads, sewers and water supply
systems. This rating reflects the continuing low
levels of government investment in basic
infrastructure. An exception is the expenditure
of $14 billion Can. ($10 billion U.S.) in sewage
treatment plant construction and sewer system
upgrades in both countries during the past two
decades as a direct result of the GLWQA. A
poor rating was also given to land use changes
because of the continuing trend to urban
sprawl and the loss of agricultural land.
Four economic indicators were rated as
mixed/deteriorating employment, research
and development, personal income, and
population growth and stability. For the years
1970 to 1990, employment growth in the basin
lagged behind that experienced overall by the
U.S. and Canada. During this period, total U.S.
employment grew at 53% while employment in
the U.S. side of the basin grew at only 25%.
Similarly, total Canadian employment during
In recent years, personal income growth in the
basin has slowed substantially, reflecting the
loss of manufacturing jobs and increase in
service sector employment. From 1970 to
1980, personal income in the basin grew by
140%; that for 1980 to 1990 grew at only 83%.
Four other indicators pollution prevention,
adoption of a stewardship approach, water
conservation, and per capita energy use
were rated as mixed/improving, reflecting
changing public attitudes towards resource
conservation and sustainable development.
Increasing public concern about environmental
issues and aggressive environmental
regulation have focused attention on
environment-economy linkages and on the
concept of sustainable development.
Strategies for a sustainable future must try to
correct the past imbalance between the
economy and the environment, and apply
ecosystem management principles and
sustainable development policies in the future.
Recognition of economic-environmental
linkages in resource management and
protection is increasing throughout the Great
STATE OF THE GREAT LAKES-1995
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33
Lakes basin. However, the leap between the
concept of sustainable development and its
application is a formidable one.
7. LAKE BY LAKE
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 known as 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 significantly 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 the relatively flat
landscape has been extensively 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.
While it is recognized that all aspects of the
ecosystem are interrelated, the agencies
responsible for management have tended to
set priorities for action because they can not
adequately deal with all the environmental
issues in their jurisdiction. In addition, the
number of jurisdictions and agencies involved
in management of the Great Lakes is quite
large - two federal, one provincial and eight
state governments, as well as thousands of
local governments and various stakeholder
groups - making the task of managing the
Great Lakes ecosystem as a whole a major
challenge. Also the management agencies
and other stakeholders such as the scientists,
general public, and industries do not always
agree on the desired ecosystem goals and
objectives for each lake.
The GLWQA addresses many of these
problems. Canada and the United States are
committed to the development and
implementation of Lakewide Management
Plans (LaMPs) for all of the Great Lakes. The
LaMPs are designed to reduce loadings of
critical pollutants so that the beneficial uses
can be restored (see Table 6 for a listing of
beneficial use impairments). Using a
comprehensive and coordinated ecosystem
approach, the Parties will also be examining
other ecosystem stressors, so that a truly
ecosystem-based management program can
be developed and delivered. There is also a
commitment to develop and implement
Remedial Action Plans (RAPs) in partnership
with state/provincial and municipal
governments and other local stakeholders
including industry, indigenous peoples and the
public. The primary purpose of the RAPs is to
restore the environmental quality in the 42
Areas of Concern (AOCs) in the Great Lakes
basin ecosystem. In addition, under the
auspices of the Great Lakes Fishery
Commission, state and provincial fishery
management agencies are developing joint
management plans. The Great Lakes Fishery
Commission was created in 1955 with the
signing of the Convention on Great Lakes
Fisheries. In 1980 fisheries management
agencies formally organized their inter-
jurisdictional activities by signing "A Joint
Strategic Plan for Management of Great Lakes
Fisheries" also known as the Strategic Great
Lakes Fisheries Management Plan (SGLFMP).
It committed fishery management agencies to
develop a set of fish community objectives and
associated environmental objectives for each
STATE OF THE GREAT LAKES-1995
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34
BENEFICIAL USE IMPAIRMENTS BY CATEGORY
Ecological Health
000EIDE!
1 . Degradation of fish and
wildlife populations
2. Degradation of benthos
3. Degradation of plankton
populations
4. Eutrophication or
undesirable algae
5. Fish tumours or other
deformities
6. Bird or animal deformities
or reproductive problems
Habitat
0
7. Loss of fish and
wildlife habitat
Human Health
00
8. Restrictions on fish and
wildlife consumption
9. Beach closings
Human Use
E9E3HII3I3I
10. Tainting offish and
wildlife flavour
1 1 . Restrictions on dredging
activities
12. Restrictions on drinking
water consumption, or
taste and odour
problems
13. Degradation of
aesthetics
14. Added costs to
agriculture or industry
Table 6. Beneficial Use Impairments
of the Lakes. The SGLFMP call for
environmental objectives relates well with the
1978 Great Lakes Water Quality Agreement
call for an ecosystem approach. Potential
linkage with SGLFMP was strengthened in
1987 with Agreement provisions calling for
development of ecosystem objectives and
indicators.
Fishery management agencies and water
quality management agencies are beginning to
work together to achieve the common
objectives of RAPs, LaMPs and fishery
management plans, but much remains to be
done in joining the separate histories and
expectations of the agencies and professions
involved.
Fishery management agencies have, over the
past 100 years, been involved in stocking
programs. These programs were originally the
direct result of the depletion of fish stocks
caused by overfishing, and more recently due
to loss of habitat and most devastatingly, the
invasion of sea lamprey. Another major reason
for stocking was the need to control nuisance
populations of alewife. The stocking strategies
involved primarily the lake trout and coho and
chinook salmon. Salmon were selected
because they mature, spawn and die in four
years, and the populations were able to
withstand lamprey predation better that the
slower growing lake trout. The salmon
stocking program has been very successful,
and has resulted in a very valuable sport
fishery. While there is some natural
reproduction of these salmon in the Lakes, the
fishery remains largely "put and take". Lake
trout stocking has, to date, been less
successful. There is little natural reproduction
of lake trout except in Lake Superior and a few
remnant stocks in Lake Huron. Loss of lake
STATE OF THE GREAT LAKES-1995
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35
trout spawning habitat may be a significant
factor in this failure.
7.1 LAKE SUPERIOR
Lake Superior is the largest of the Great
Lakes in both surface and volume. It is
also the deepest and coldest of the five. In
volume Superior could contain all the other
Great Lakes and three more Lake Eries.
Among the lakes of the world, Lake Superior is
the largest freshwater lake in area. In volume,
it is the third largest in the world. Because of
its size, Superior has a retention time of 191
years. Retention time is a measure of the
volume of water in the Lake and the average
rate of flow out of the lake. Additional
information on Lake Superior can be found in
Table 1.
The basin population is approximately 740,000
which is 2% of the total for the Great Lakes
basin. Approximately 75% of the Lake
Superior population lives within the U.S. The
population and industrial base is small, and
most of the Superior basin is forested with little
agriculture because of the cool climate and
poor soils. Relatively small quantities of
pollutants enter Lake Superior directly, except
through airborne deposition.
In terms of environmental quality, Lake
Superior is distinguished by its high quality
compared to the other Great Lakes and many
parts of the U.S. and southern Canada. This is
due in large part to the relatively small
population and very limited industrial base.
Notable exceptions to this high quality are the
seven Areas of Concern where beneficial uses
including the aquatic communities are
impaired. AOCs include- the lower reach of
the St. Louis River/Bay near Duluth, MN and
Superior, Wisconsin; Thunder Bay, Ontario;
and the smaller areas of Jackfish Bay, Nipigon
Bay and Peninsula Harbour in Ontario and
Torch and Deer Lakes in Michigan. Progress
is being made in restoring beneficial uses to all
of the AOCs as reported in Progress in Great
Lakes Remedial Action Plans: Implementing
the Ecosystem Approach in Great Lakes Areas
of Concerns and as seen in Table 6.
Most of the losses within the aquatic
community occurred in previous decades
during exploitation of natural resources,
particularly excessive fisheries harvests
followed by impacts of the sea lamprey. The
most severe and permanent loss has been to
the lake trout population which lost many
genetic stocks, most notably all those that
spawned in tributaries. Although the remaining
stocks are reproducing naturally, the
population has not yet become fully self-
supporting, since hatchery fish are still needed
to supplement natural reproduction.
Despite genetic losses within fisheries stocks,
biodiversity within the Lake Superior basin is
relatively unimpaired compared to the other
Lakes. Tributary habitat is degraded in many
areas, but there are also large tracts of very
high quality habitat. The challenge in Lake
Superior is to preserve the relatively high
quality areas that exist throughout the basin.
In terms of stressors, the greatest threats to
the aquatic community at present are the river
ruffe and sea lamprey. Ruffe is an exotic
species with no commercial or sports value,
introduced into Duluth Harbor in ballast water
from transatlantic cargo vessels. It is steadily
spreading through near shore waters and it is
feared that it will have severe impact on perch
and other native species. On the other hand,
sea lamprey invaded the Great Lakes system
in the 1800s, probably via the Erie barge canal.
STATE OF THE GREAT LAKES-1995
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36
With the opening of the Welland Canal, and
later the Sault locks, the lamprey gained
access to all five Lakes. With no natural
predators, the lamprey devastated the lake
trout populations in Lakes Ontario, Erie,
Michigan and to some extent Huron. Some
stocks were lost in Lake Superior, but sea
lamprey control, started in 1958, managed to
halt the loss. The sea lamprey control program
has resulted in a 90% reduction in lamprey
abundance in Lake Superior. Without
continued lamprey control, it is unlikely that
lake trout populations could be sustained.
Chemical stressors of concern are
bioaccumulative persistent toxic substances.
Although Lake Superior receives
proportionately little input of contaminants in
comparison to its volume, they remain
available to the food chain for a relatively long
time. This is because there is little algae or
suspended particles to absorb them and carry
them to the bottom. There are nine chemicals
of concern, as outlined in the Lake Superior
Binational Program including mercury, DDT,
PCBs and toxaphene-like substances.
Toxaphene remains in the aquatic environment
for a very long time and is mainly a problem in
Lake Superior as well as northern Lake
Michigan. Although data on toxaphene are
complicated by analytical limitations, it appears
that concentrations are showing little response
to cancellation of its use as an insecticide. It is
present in some Lake Superior fish at levels
that require fish consumption advisories.
The largest external source of contaminants to
Lake Superior is the atmosphere, via wet and
dry deposition. This is the most difficult source
LAKE SUPERIOR
Area of Concern
Peninsula Harbour
Jackfish Bay
Nipigon Bay
Thunder Bay
St. Louis River
Torch Lake
Deer Lake
IMPAIRMENT CATEGORY
Ecological Health
DDKin
aaBH
BOB ED
ana
BDOBEI
DHDDDD
aaaaaa
Habitat
D
D
Human Health
0
HO
DO
ฉD
a
Human Use
oHoaa
DBDBn
BDBD
DBDBB
BBOBD
annnn
DODPCJ
= Impaired Use
E3 = Likely, Suspected, Under Assessment, or Unknown Impairment
O = No Impairment
ฉ - Restored Use
For a more complete breakdown of impairments see Table 6
Table 7. Areas of Concern for Lake Superior
STATE OF THE GREAT LAKES-1995
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37
to control since the contaminants may travel
hundreds or even thousands of miles, and may
undergo many chemical transformations,
before being deposited on the Lake.
Atmospheric deposition accounts for
approximately 90% of some toxic contaminants
input into Lake Superior. For semi-volatile
compounds such as PCBs, however, outputs
to the atmosphere can be a substantial fraction
of total inputs (see Figure 18). Nitrogen is
being monitored in the Lake with trends
showing that it is increasing, although these
increases have no apparent effect on the
ecosystem. Input of nitrogen to the Lake from
the atmosphere is suspected of being the
major cause of nitrogen increases in the Lake.
An estimated 58% of the total nitrogen load to
the Lake is attributable to precipitation. The
trends in contaminant concentrations in fish
can be seen in Figure 10. For PCBs,
concentrations in lake trout declined
significantly during the period 1977-1990 in
Lake Superior as in the other Great Lakes.
However, as in the other Lakes, the declines
have not continued in recent years as can be
seen in Figures 10 and
11. Whether this is the
result of continuing
sources, recycling of
previous discharges or
changes in the food chain
remains to be seen.
Fish consumption
advisories are in effect for
many Lake Superior fish
because of contaminants.
Advisories are issued by
states and the province by
species and size of fish.
The public is advised not
to eat the siscowet form of
lake trout at any time and
to limit consumption of other lake trout, brown
trout, steelhead, coho salmon, chinook salmon,
white fish, walleyed pike, smelt, and lake
herring. The recommended limits for
frequency of consumption differ by species and
by political jurisdiction, so it is important for
consumers to consult consumption guides in
their respective jurisdictions.
Despite the foregoing, Lake Superior is still
considered to be the most pristine of all the
Great Lakes. The International Joint
Commission (IJC) called on Canada and the
U.S. in 1989 to declare Lake Superior an area
where no further point sources of persistent
toxic chemicals would be permitted. The
Parties responded in 1991 with the Lake
Superior Binational Program. This calls for the
water quality to be maintained and enhanced,
to protect, and where necessary, restore the
integrity of Lake Superior's ecosystem, as well
as outlining a zero discharge demonstration
project for nine critical toxic substances from
point sources. An action plan has been
developed and many actions have already
INFLOW
DEPOSITION
WET DRY ABSORPTION VOLATILIZATION
OUTFLOW
4200
Kg/year
370
Figure 18. PCB Budget for Lake Superior 1992
STATE OF THE GREAT LAKES-1995
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38
been taken to move towards zero discharge.
However the effectiveness of the zero
discharge program in eliminating the impacts of
persistent toxic substances also depends upon
the effectiveness of programs to deal with the
airborne deposition of these substances.
The Binational Program is evolving and
broadening to include all of the elements of a
Lakewide Management Plan as well as natural
resources, habitat, exotic species and
biodiversity issues. It is building upon the
ecosystem objectives and indicators identified
in the Great Lakes Water Quality Agreement
and also upon fish community objectives
developed in response to the Strategic Great
Lakes Fisheries Management Plan.
The background and problem definition
portions of the LaMP are nearing completion
for critical pollutants, other stressors and
ecosystem objectives and are to be presented
to the IJC by September 1995. A schedule of
necessary load reductions for critical pollutants
is being developed and will be provided to the
IJC following public comment.
7.2 LAKE MICHIGAN
Lake Michigan, the third largest in area, is
the only Great Lake entirely within the
United States. It is the fourth largest
freshwater lake in the world in terms of area
and fifth largest in terms of volume. Water
retention time in the Lake is estimated at
approximately 100 years.
The northern part is in the colder, less
developed upper Great Lakes region. It is
sparsely populated, except for the lower 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 eight million people or about one-fifth of
the total population of the Great Lakes basin.
The basin as a whole has a population of
approximately 14 million. Fortunately for the
Lake, drainage for much of the Chicago area
has been redirected out of the Great Lakes
basin. For additional information on Lake
Michigan see Table 1.
Environmental quality in the basin generally
follows a north south gradient, being best in the
north and degrading to the south. There are
ten Areas of Concern around the Lake where
the worst degradation exists (see Table 8). In
terms of magnitude, the Indiana Harbor,
Milwaukee and Green Bay AOCs are the
largest and most degraded although the
Kalamazoo River contains very large quantities
of PCBs. Manistique, Menominee,
Sheboygan, Muskegon and White Lake are
less degraded, but still have beneficial use
impairments.
The aquatic community in Lake Michigan has
undergone huge changes. The fishery was
very productive until over fished and decimated
by exotic species. The sea lamprey eliminated
all stocks of lake trout and severely depressed
whitefish and other populations. Lamprey
populations declined substantially after control
measures were implemented in the 1960s,
thus allowing for the increased survival of the
stocked trout and salmon. Current increases in
lamprey wounding rates of lake trout in
northern Lake Michigan are thought to be a
result of the proximity to the St. Marys River.
STATE OF THE GREAT LAKES-1995
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39
Alewife populations exploded in the absence of
predators; and during the die-offs of the 1950s
and 1960s were estimated to constitute as
much as 90% of the biomass in the Lake.
Coho salmon, chinook salmon, rainbow trout
and brown trout were stocked to support a
sport fishery and control alewife through
predation. Alewife populations have decreased
to 20% or less of their former abundance as a
result of poor over-winter survival and
predation from the stocked predators. As a
result, native burbot, yellow perch, and bloaters
have made a spectacular recovery since the
early 1980s. Bloaters are now more abundant
than alewife were in the 1970s.
Algae and zooplankton populations have also
undergone major changes due to changing
predation by fish, changes in water quality and
invasion by exotic species such as the spiny
water flea and zebra mussels. What the long
term aquatic community will be, remains
unknown.
The sport fishery remained productive until the
mid 1980s when a bacterial kidney disease
LAKE MICHIGAN
Area of Concern
Manistique River
Lower Menominee River
Lower Green Bay and Fox
River
Sheboygan River
Milwaukee Estuary
Waukegan Harbor
Grand Calumet River/
Indiana Harbor Ship Canal
Kalamazoo River
Muskegon Lake
White Lake
IMPAIRMENT CATEGORY
Ecological Health
DBnnnn
MDDDD
HI
HMD DEI
nnnnrjB!
BBBBDH
BIDS
Habitat
Human Health
a
a
a
a
Human Use
DBDBD
DBnnn
HBBBO
nBnan
aBoBa
HBaaa
BBBBB
aaaan
DBBBD
QBBBa
= Impaired Use
El = Likely, Suspected, Under Assessment or Unknown Impairment
O = No Impairment
ฉ = Restored Use
For a more complete breakdown of impairments see Table 6
Table 8. Areas of Concern for Lake Michigan
STATE OF THE GREAT LAKES-1995
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40
(BKD) outbreak reduced the abundance of
Chinook salmon by 50% or more. Sport fishing
effort also dropped by more than 50% in some
states because chinook salmon comprised the
majority of the sport catch. The cause of the
BKD outbreak remains unknown. In addition,
a sharp decline in the survival of coho salmon
eggs in hatcheries began in the early 1990s.
This lack of survival was designated as "early
mortality syndrome". Treating the eggs in the
hatchery with thiamine reverses the syndrome,
but the ecological cause of the syndrome
remains unknown. The goal of self sustaining
lake trout populations based on natural
reproduction remains elusive, but whitefish and
bloater populations have increased and
support a valuable commercial fishery. Habitat
losses, especially wetlands, have been
extensive throughout the basin, but have been
most severe in the southern portion. Losses in
habitat and biodiversity continue to add up as
major stressors continue unabated. Urban
sprawl and recreational development continue
to destroy habitat and biodiversity as they do
throughout the Great Lakes basin. Progress is
being made in inventorying existing resources,
but losses far exceed conservation and
restoration efforts.
Accelerated eutrophication has been brought
under control except in localized areas, and in
Green Bay where good progress has been
made, but much remains to be done. In Green
Bay seven of the 12 impaired uses are the
result of excessive nutrients. This case is a
good example of problems caused by nutrients
and how it has become recognized that land
runoff must be addressed on a watershed
basis if these problems are to be solved.
Trends for bioaccumulative persistent
contaminants are similar to the other Lakes as
described in section 4.2. Contaminants in fish
in Lake Michigan are among the highest in the
Great Lakes, being similar to levels in Lake
Ontario (see Figure 10).
Fish consumption advisories are in effect for
lake trout, brown trout, steelhead, coho
salmon, Chinook salmon, whitefish, walleyed
pike, perch and smelt. It is advised that large
lake trout and brown trout should not be eaten
at all, whereas it is recommended that
consumption of the others be in limited
amounts. Advisory recommendations for
frequency of consumption differ by species,
size and location, so it is important for
consumers to consult consumption guides in
their respective jurisdictions.
On a lakewide scale contaminants are being
addressed by both the Lakewide Management
Plan (LaMP) and the Lake Michigan Mass
Balance Study. A draft LaMP for critical
pollutants for Lake Michigan was published
early in 1995. The LaMP reviews
contaminants, their effects and their loadings,
and also incorporates five ecosystem
objectives derived from the Lake Ontario
LaMP. Following public comment and
appropriate revision the plan will be adopted.
Although the plan is primarily focused on toxic
contaminants, work is currently underway to
develop an expanded plan which will include
natural resource and habitat factors as well as
pollutants. Also, further efforts are underway
to strengthen the science base for dealing with
contaminants.
To obtain better information on the sources,
loadings and behaviour of toxic contaminants
the U.S. Environmental Protection Agency
together with various the state and federal
agencies are conducting Lake Michigan Mass
Balance Study. The study is seeking to
determine how toxic contaminants move into
STATE OF THE GREAT LAKES-1995
-------
41
and through the Lake ecosystem. A
mathematical model of Lake Michigan is to be
constructed based upon intensive sampling.
Sampling includes inputs from tributaries and
airborne deposition, sediment burial and
resuspension, and movement of contaminants
through foodchains (Figure 19). The purpose
is to better predict the benefits of reducing
contaminant loads in terms of resulting
decreases in contaminant levels in fish. The
multi-year study will support improved
management of contaminants throughout the
Lake Michigan basin.
Fish community objectives for Lake Michigan
were approved in 1995 in response to the
Strategic Great Lakes Fisheries Management
Plan and are to be factored into the LaMP.
7.3 LAKE HURON
Lake Huron, including Georgian Bay, is the
second largest in area. It is the third
largest freshwater lake in the world in area and
sixth in volume. The population is
approximately 2.4 million with about 55% of the
population in the U.S. Like Lake
Michigan, the northern portion is
lightly populated and extensively
forested. In contrast, the Saginaw
River basin is intensively farmed
and contains the Flint and
Saginaw-Bay City metropolitan
areas. Saginaw Bay, like Green
Bay in Lake Michigan, contains a
very productive fishery. For
addition information on Lake Huron
see Table 1.
Lake Huron is literally the lake in
the middle, both geographically and
in environmental quality. It has
relatively good quality of water and
wetlands except in the Areas of Concern. The
fishery is relatively healthy except for the
lamprey threat from the St. Marys River,
discussed later in this section. Originally, there
were five AOCs on Lake Huron. One of them,
Collingwood Harbour, has since been cleaned
up and was taken off the list of AOCs in 1994.
The binational St. Marys area at the head of
the Lake was originally designated because of
contaminants, but is also a major and growing
source of lampreys. Control of industrial
sources is progressing and pollution loads are
being reduced. The two other Canadian
AOCs, Spanish River and Severn Sound are
responding well to remedial actions and
showing recovery (Table 9).
The remaining AOC is Saginaw Bay. The Bay
is a rich biological resource and is the largest
freshwater coastal area in the U.S. with a water
surface of 1,143 square miles (2960 square
kilometres). Biodiversity of the Bay and its
watershed remains quite high although 138
plant and animal species have been identified
as endangered, threatened or of special
concern. The area continues to provide
Atmosphere Transport
to/Water OyPareote
Exchange Deposition
Figure 19. Mass Balance Diagram
STATE OF THE GREAT LAKES-1995
-------
42
LAKE HURON
Area of Concern
Saginaw River/Bay
Collingwood Harbour
Severn Sound
Spanish Harbour
IMPAIRMENT CATEGORY
Ecological Health
mmmmom
ฉDDฉDD
DBDD
HBDDH
Habitat
ฉ
B
Human Health
ฉa
a
Human Use
mmmma
DDDDD
niain
DBDDB
= Impaired Use
H = Likely, Suspected, Under Assessment or Unknown Impairment
O = No Impairment
ฉ = Restored Use
For a more complete breakdown of impairments see Table 6
Table 9. Areas of Concern for Lake Huron
essential habitat for both fish and wildlife with
more than 3 million waterfowl migrating
through the area annually.
Historically there were approximately 37,000
acres (14,800 hectares) of emergent marsh
around the Bay, but less than half remains.
Throughout the watershed, wetlands originally
covered approximately two thirds of the basin
but now cover only about 15%.
The Bay receives runoff from an 8,700 square
mile (22,530 square kilometre) watershed that
contains 1.4 million people, approximately 35%
of the population of the entire Lake Huron
basin. The watershed of the Bay also contains
large amounts of industry and intensive
agriculture. As a consequence, it has received
heavy loadings of nutrients and toxic
contaminants. Loadings have been reduced,
but problems of contamination and
eutrophication continue, partially due to
recycling of old deposits.
In addition to human stresses, the most recent
problem, the zebra mussel invasion, has the
potential to significantly impact biological
communities and contaminant cycling in the
Bay.
For the remainder of Lake Huron, aquatic
community health and biodiversity is perceived
as being relatively good, at least in
contemporary terms and in comparison to the
other Lakes. The forage fish population
appears to be healthy. Walleyes are
recovering locally in both Saginaw Bay and
Severn Sound. Whitefish have recovered and
are at historically high levels. However, there
is some concern over whether current levels of
walleye are sustainable, particularly with
growing populations of lampreys and unknown
food chain impacts resulting from zebra
mussels. There is also concern over the
continued health of other large fish in northern
Lake Huron due to the threat of lamprey.
Additionally, lake trout populations are still not
STATE OF THE GREAT LAKES-1995
-------
43
self sustaining. They are genetically
impoverished and rely on hatcheries for
reproduction. Declining walleye populations in
Georgian Bay are another concern.
Consumption advisories with respect to
amount and frequency of consumption are in
effect for chinook salmon, coho salmon, brown
trout, steelhead, walleyed pike and yellow
perch. As in other lakes, advisories differ by
species, size and location so it is important to
check advisories in effect for the appropriate
state or provincial jurisdiction.
Lake Huron is the most important Lake of all
the Great Lakes in terms of having the highest
number of fish-eating birds that breed along
lake shorelines. This is due to the diversity
and area! extent of habitats available to the
birds on the Lake. Most populations of the
fish-eating breeding birds are increasing, for
example cormorants, Caspian terns, and
osprey. Pairs of bald eagles have returned to
nest along the Lake Huron shoreline. The
herring gull population is declining in a few
areas on the Lake but this is probably due to
changes in the fish community structure rather
than contaminants. Caspian terns and osprey
are no longer showing adverse effects of
contaminants, however, they are not as
sensitive to the current contaminants as other
species. Loss of shoreline marshes and
wetlands have been moderate compared to the
other Lakes except in Saginaw Bay. However,
continuing loss of wetlands along the shores
and tributaries is a serious threat to habitat,
one aspect of which is loss of resting and
feeding areas for migratory waterfowl. Some
of the important staging areas on Lake Huron
for migrating birds include the wetlands of
Saginaw Bay, Severn Sound and the St. Marys
River. Physical habitat loss in the past, in
southern Lake Huron, was catastrophic as land
was converted to agriculture and streams were
dammed for various purposes.
With respect to stressors affecting Lake Huron,
exotic species such as sea lamprey, zebra
mussels, and purple loosestrife and other
organisms pose major threats. Shortly after its
arrival in the Lakes, the sea lamprey population
exploded and nearly eliminated native fisheries
by the 1950s and 1960s. In the late 1950s
Canada and the U.S., under the auspices of
the Great Lakes Fishery Commission, began
treating tributaries and coastal waters with
TFM, a chemical used to kill lamprey larvae in
streams. By the 1970s the lamprey population
had been reduced by 90% throughout the
Great Lakes. However, lamprey are a growing
threat in Lake Huron with populations doubling
in northern Lake Huron since 1985. Using
current methodologies, the population
reproducing in the St. Marys River cannot be
treated because of the large flow in the River
and the many bays and side channels. Since
salmon transport lamprey throughout the Lake,
the problem will likely spread.
As shown in Figure 20 lamprey control is vital
and should continue as a priority before the
fisheries in Lake Huron are lost. More
information is needed on the distribution of
adult and larval lamprey as part of the search
for non-chemical controls. Development of
non-chemical controls are needed not only for
the St. Marys River, but to allow reduced use
of chemical treatment which has some
undesireable side-effects. Efforts to deal with
the problem are being coordinated by the
Great Lakes Fishery Commission but costs
may increase substantially. Invasion by zebra
mussels has yet to run its full course and little
can be done except to monitor its progress and
try to understand the cause and effect
relationships involved. The full impact on the
STATE OF THE GREAT LAKES-1995
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44
food chain, aquatic community and biodiversity
remains to be seen.
Contaminant levels in Lake Huron fish and
birds are declining as they are in the other
Lakes as seen in Figures 10 and 11.
Continuing sources of contaminants are
primarily from sediments from earlier
discharges, airborne deposition and land
runoff.
Shoreline development is a growing stress on
habitat and aquatic communities as marshes
and other wetlands are dredged, drained or
filled, often for recreational development,
including summer homes and cottages.
Although the change is taking place in small
increments, the collective effect is substantial.
The most intense areas of impact are the result
of urban population pressures from both Detroit
and Toronto.
An emerging issue is how public and private
natural resource lands within the basin are
managed. Often land is managed by
individual agencies or organizations
carrying out single, often narrow,
mandates. The efforts to maximize a
narrow objective can have major negative
impacts on the aquatic community as a
whole or on components within it.
There is a danger of complacency for
Lake Huron. As the "lake-in-the-middle",
it is the lake without high-profile issues or
advocacy groups to focus attention on it.
Nonetheless, the problems are real and
there is a need to identify what most
needs to be protected and restoration. A
plan for action is then needed to address
the problems. Fish community objectives
have been approved, but there is
currently no LaMP structure in place and
is unlikely to start before 1998 due to a scarcity
of resources. What is needed is a process for
developing a Lakewide Management Plan that
includes both environmental quality and
fisheries management.
7.4 LAKE ERIE
Lake Erie is the smallest of the Lakes in
volume and second smallest in area. Yet
it is still the tenth largest freshwater lake in the
world in terms of surface area and 16th in
volume. Of all the Great Lakes it is exposed to
the greatest stress from urbanization and
agriculture. The Lake receives runoff from the
rich agricultural lands of southwestern Ontario
and parts of Ohio, Indiana and Michigan.
Seventeen metropolitan areas of over 50,000
population are located within its basin. The
basin population is approximately 13 million
with approximately 88% of the population
within the U.S. For Additional information on
Lake Erie see Table 1.
350000 -
300000 -
250000
200000 -
150000-
100000-
50000 -
0
Superior Michigan Huron Erie
IH Current | Target
Ontario
Figure 20. The Status of Current Sea Lamprey
Populations in the Great Lakes (and control program
targets for their suppression)
STATE OF THE GREAT LAKES-1995
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45
LAKE ERIE
Area of Concern
River Raisin
Maumee River
Black River
Cuyahoga River
Ashtabula River
Presque Isle Bay
Wheatley Harbour
Buffalo River
IMPAIRMENT CATEGORY
Ecological Health
QBDDDD
Homo
BBBHBH
amฎ
BBDDBD
DHDnBn
DBDBBID
BBDDBB
Habitat
0
D
B
B
D
B
B
Human Health
BD
BB
BB
BB
Bn
DB
DEI
BD
Human Use
OBDDD
OBBBD
BBQBB
HBBBa
DBana
DBaoo
DBDDD
BBDDD
= Impaired Use
13 = Likely, Suspected, Under Assessment or Unknown Impairment
P = No Impairment
ฉ = Restored Use
For a more complete breakdown of impairments see Table 6
Table 10. Areas of Concern for Lake Erie
There are eight Areas of Concern on Lake Erie
(Table 10), but four more from the Detroit and
Sarnia areas contribute to its problems. The
Buffalo AOC has little affect on the Lake as
most of its discharge is drawn into the Niagara
River and into Lake Ontario. Presque Isle,
Pennsylvania and Wheatley Harbour, Ontario
are relatively small, but the others are major
problem areas. The Ashtabula, Cuyahoga,
Black, Maumee and Raisin River areas all
present formidable problems as do the St.
Clair, Clinton, Detroit and Rouge River areas
upstream.
The Lake is large in area, but the average
depth is only about 19 metres (62 feet). It is
the shallowest and therefore warms rapidly in
the spring and summer and 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). The waters of
the Lake, like the surrounding farm lands, are
highly productive; far more productive than the
other Lakes.
Although the Lake Erie basin is the most
intensively populated and farmed, pollution
loading has been mitigated through
sedimentation from the productive algae and
fine soil particles from farmland erosion.
STATE OF THE GREAT LAKES-1995
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46
Therefore, with respect to toxic contaminants,
Lake Erie organisms have historically shown
relatively low concentrations compared to the
other Lakes. As eroded soil and nutrient levels
decline and zebra mussels deplete algal
populations, this may change, increasing rates
of bioaccumulation.
In terms of environmental quality, Lake Erie is
severely degraded with respect to habitat.
Although never "dead" as reported in the
1960's, it was severely stressed by
eutrophication stimulated by excess nutrients.
The resulting algal blooms closed beaches,
disrupted food chains and aquatic
communities, and caused wide spread oxygen
depletion in the central basin. Massive
investment in municipal and industrial waste
treatment and voluntary programs to control
agricultural land runoff have produced excellent
results. They have achieved target levels and
are producing the biological results expected.
Oxygen depletion still occurs in the bottom
waters of the central basin, but to a diminishing
extent. Phosphorus concentrations in the
western basin have nearly reached target
levels but sediment resuspension during
storms results in recycling of nutrients from
bottom deposits.
The near total removal of native vegetation
from the basin, and severe exploitation of
fisheries followed by exotic species invasions,
have devastated the original aquatic
community of the Lake. Recovery is under
way, but the long term nature of the resulting
community is unknown. Species having
particularly heavy impact include zebra
mussels, and carp. Others such as alewife,
smelt, white perch, pacific salmon, and most
recently the round goby have added stress to
the system.
Zebra and quagga mussels are closely related
exotic species that prefer habitats typical of
Lake Erie. The two species are very similar, a
major difference being that quagga prefer
deeper water than zebra mussels. Without any
natural predators or diseases, their populations
have exploded. Both mussels are voracious
filter feeders, and as such, have had profound
effects on the Lake's ecosystem including
abrupt changes in water quality, water clarity
and the food web.
By consuming large amounts of phytoplankton,
they have increased water clarity (a 77%
increase in water transparency has occurred
between 1988 and 1991). By increasing the
clarity of the water, sunlight is able to penetrate
deeper, allowing rooted aquatic plants to
spread into deeper water. This has had
ecological benefit to many organisms but has
interfered with swimming and boating in some
areas.
The eating habits of mussels have led to large
changes in the food web which may result in
major changes in the future abundance of
various species of fish. They have depleted
the food source (phytoplankton) for other filter
feeders, and have also assimilated toxic
contaminants. By removing large amounts of
particulates, which formerly
absorbed/adsorbed pollutants, more
contaminants are left in the water. This could
result in higher contaminant concentrations in
the remaining phytoplankton and zooplankton
as well as higher concentrations in fish and
wildlife species feeding on the plankton or
directly on the mussels and other benthos
(bottom dwellers). The results of the zebra
mussel invasion have become far more
complex than the physical problems of clogging
intake pipes or jamming machinery.
STATE OF THE GREAT LAKES-1995
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47
Although not yet established in Lake Erie
another exotic species to be concerned with is
the ruffe. Ruffe habitat consists of warm
shallow water such as found in much of Lake
Erie. In fact, considering all of the Great
Lakes, Lake Erie has over half the thermally
suitable habitat. Potential effects of large
populations of ruffe on fish communities are
unknown, but if it were to become as abundant
in all the thermally suitable habitat as it did in
the St. Louis River estuary of Lake Superior, it
would be a major problem for the Great Lakes
fisheries. A decline in the yellow perch
abundance similar to that seen in the St. Louis
River estuary would seriously impact the
fishery which is presently valued at $141
million Can. ($101 million U.S.) in Lake Erie
alone for yellow perch.
Historically, the top commercial fish in Lake
Erie included whitefish, walleye, blue pike, lake
trout (only found in the eastern basin of Lake
Erie in the colder deeper waters) and sturgeon.
The demise of the lake trout was mainly a
combination of overharvesting and
environmental stress. The populations of
whitefish, walleye and sturgeon have
diminished from overfishing and blue pike
became extinct. In 1970 high levels of mercury
led to the closure of the commercial walleye
fisheries in the U.S. and Canada as well as
restrictions on the retention of walleyes caught
by anglers. After 1972 the mercury levels had
declined and the walleye fishery re-opened in
Ontario to both sport and limited commercial
use; however in Michigan and Ohio it was
restricted to angling. Due to the relief from
commercial fishing and to the quotas imposed
after re-opening the fishery, the walleye fishery
of the western basin has shown a spectacular
recovery.
Some fish consumption advisories are in effect
for lake trout, Chinook salmon, coho salmon,
walleyed pike, smallmouth bass and white
bass. As in other lakes, advisories differ by
species, size and location so it is important to
check with the appropriate state or province.
A LaMP (Lakewide Management Plan) is
currently being developed for Lake Erie, in
accordance with the GLWQA, between the
Canadian and U.S. federal governments, the
four Great Lakes states (Ohio, Michigan,
Pennsylvania, and New York) and the province
of Ontario. The goal of the LaMP is to restore
and protect the beneficial uses of Lake Erie
using an ecosystem approach. It will address
critical pollutants, habitat loss, exotic species
and natural resource management including
fish community objectives. Fish community
objectives are being developed in response to
the Strategic Great Lakes Fisheries
Management Plan and are currently under
review.
Four critical pollutants have already been
identified for immediate action: PCBs, DDT and
metabolites, chlordane, and dieldrin, and the
remainder of pollutants will be identified
through the beneficial use impairment
assessment. LaMP activities will closely
coordinate with the Remedial Action Plans for
the AOCs in the Lake Erie drainage basin, as
well as coordinating with programs
downstream such as the Niagara River Toxic
Management Plan and the Lake Ontario LaMP.
Lake St. Clair
Lake St. Clair is a relatively small shallow lake
of 1114 square kilometres (430 square miles)
and a volume of 4.2 cubic kilometres (1 cubic
mile). It lies between Lakes Huron and Erie
but is completely within the Lake Erie drainage
basin. There is a high population and industrial
base surrounding it. This has led to the loss of
STATE OF THE GREAT LAKES-1995
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48
much of the surrounding habitat/wetlands, and
to contaminant problems in both the water and
the sediments. Lake St. Clair and the St. Clair
River are very important staging areas for
migrating birds and fish, so habitat loss is a
real concern. Zebra mussels are having a
major impact on the Lake St. Clair ecosystem
but the end result remains unknown. One
effect of the mussels has been improved water
clarity. This in turn has altered the nutrient
cycling and food chains, as well as allowing
aquatic vegetation to spread throughout the
Lake. The vegetation provides improved
habitat, but impedes some recreational uses.
As mentioned previously, there are four AOCs
in the Lake St. Clair area which affect Lake
Erie: St. Clair, Clinton, Detroit, and Rouge
River. There is no specific LaMP for the Lake
although it will receive some consideration as
part of the Lake Erie LaMP. Fish community
objectives have been developed for Lake St.
Clair.
7.5 LAKE ONTARIO
Lake Ontario, although slightly smaller in
area, is much deeper than its upstream
neighbour, Lake Erie, with an average depth of
86 metres (283 feet) and a retention time of
about six years. In terms of world rank of
freshwater lakes, Lake Ontario is 13th in area
and 11th in volume. Major urban industrial
centres, such as Hamilton, Toronto and
Rochester are located on its shore. The U.S.
shore is less urbanized and is not intensively
farmed, except for a narrow coastal plane.
There are approximately 6.6 million people
living within the Lake Ontario basin of which
nearly 69% reside in Canada. Most of the
population is concentrated in the western half
of the basin, including the Toronto-Hamilton
crescent, that contains more than half of the
entire Canadian Great Lakes basin population.
U.S. population is concentrated in the
Rochester and Syracuse-Oswego areas. Lake
Ontario is also directly impacted by the Buffalo-
Niagara area since pollutant loadings from that
area typically flow into Lake Ontario via the
Niagara River, rather than mixing into Lake
Erie.
The aquatic community of Lake Ontario as in
the other Lakes, suffered major losses
because of agriculture, deforestation, damming
of streams and urbanization. Atlantic salmon
was extirpated through over-fishing and
sedimentation of spawning habitat.
Lake Ontario contains seven AOCs (Table 11),
of which Toronto and Hamilton Harbour are
the largest. The others are Port Hope and the
Bay of Quinte in Ontario and Eighteen Mile
Creek, Rochester and Oswego in New York.
An eighth, the Niagara River AOC, supplies
approximately 70% of the toxic contaminant
loading to Lake Ontario. Lake Erie's Buffalo
River also primarily impacts Lake Ontario
rather than Lake Erie.
Lakewide, accelerated eutrophication has been
brought under control, but remains a problem
in localized bays and river mouth areas,
notably Hamilton Harbour and the Bay of
Quinte.
Contaminant levels in fish are following trends
similar to the other Lakes as described in
section 4.2 (and shown in Figure 10) but are
relatively high and similar to those in Lake
Michigan. The levels of contaminants are
being maintained by the continued inputs from
point and non-point sources, from atmospheric
deposition and locally from the sediments.
STATE OF THE GREAT LAKES-1995
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49
LAKE ONTARIO
Area of Concern
Eighteen Mile Creek
Rochester Embayment
Oswego River
Bay of Quinte
Port Hope Harbour
Metro Toronto and Region
Hamilton Harbour
IMPAIRMENT CATEGORY
Ecological Health
Habitat
Human Health
Human Use
Still Under Assessment
BBBBBB
BBBBBH
BBBHD
aaanna
BIBB
am
D
BB
D
DD
BB
HDBBB
DODHD
DBBBD
OIDDO
DBDBO
DBOBD
= Impaired Use
El = Likely, Suspected, Under Assessment or Unknown Impairment
n = No Impairment
ฉ = Restored Use
For a more complete breakdown of impairments see Table 6
Table 11. Areas of Concern for Lake Ontario
Levels declined rapidly in the 1970s and early
1980s but since that time contaminant levels in
the biota have declined much more slowly or
even, in a few cases, increased (Figure 21).
Mirex and photomirex are contaminants
whose impacts are mainly confined to Lake
Ontario fish and fish-eating birds, although
very low levels (100-200 times less) have
been found in Lakes Erie and Huron birds
and fish. Mirex concentrations in fish have
declined significantly since the 1980s in
Lake Ontario. Increases were observed in
1991 and 1992, but they are thought to be
the result of changes in the food chain
rather than increased loadings to Lake Ontario.
Nevertheless the concentrations remain high
enough to be the basis for some fish
consumption advisories.
In Lake Ontario consumption advisories are in
effect for lake trout, Chinook salmon, coho
salmon, brown trout, rainbow trout, walleye,
white sucker and white perch. As in the other
Lakes, advisories differ by species, size and
location, so it is important that consumers
check with the appropriate state or province.
The present fishery of Lake Ontario is
maintained by stocking hatchery reared fish,
primarily pacific salmon. Originally introduced
to control alewife they have become the basis
of an economically important sport fishery.
STATE OF THE GREAT LAKES-1995
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50
2500-
2000-
c
01
| 1500-
o
I loco-
s'
O)
a
500-
71 7
II.
IHInli _
iBBlllBBlBraii-HH.--
TTTTTTTTTTTTTTTTT
2 73 74 75 76 77 78 79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92
Year
Figure 21. Dioxin (2,3,7,8- Tetrachloro-di-benzo-dioxin)
Concentration in Herring Gull Eggs from Eastern Lake Ontario
1971-1992
However, there is a question as to whether
reliance of hatcheries on non-native fish can be
naturally sustained in the long term.
In 1984, the management agencies of the Lake
Ontario fishery stocked 8.2 million fish. Since
that time, they have recognized that there is
not enough food to sustain this amount of
stocked fish. It is estimated that Lake Ontario
will support 4-5 million of "put and take" fish
added each year. As a result the agencies
have decreased the amount of fish stocked in
Lake Ontario each year so that by 1994 the
amount stocked was almost half that of a
decade ago (4.5 million fish were stocked in
1994). The province of Ontario has also
encouraged increased harvesting of salmon
and trout to reduce the demand for food by
predator fish. There is still the question of
rehabilitating the Lake Ontario fishery to a
more "natural" system with, for example, a top
predator species such as Atlantic salmon.
Since Atlantic salmon depend
on tributaries for spawning,
they would also be a good
indicator of Lake Ontario
ecosystem health. However,
much of the Atlantic salmon
habitat has been destroyed
through deforestation, stream
modification, dams and pH
changes. These factors were
largely responsible for the
demise of the Atlantic salmon
in the late 1800s. It would
take more than merely
stocking the fish to restore
them.
Habitat and biodiversity
losses continue, most notably
due to urban sprawl and
agricultural practices. The
bald eagle illustrates the
combined effects of habitat
loss and toxic chemicals on birds of prey. Bald
eagles were extirpated from many of the
islands and shorelines of the Great Lakes in
the 1950s and early 1960s due to effects of
DDT (causing egg shell thinning). However,
prior to widespread use of DDT, eagle
populations were already in decline. The loss
of nesting habitat, changes in fish populations,
and persecution by humans were some of the
reasons for their initial decline. Together the
remaining contaminant levels and the lack of
habitat (mature eagles favour coniferous
perches away from human disturbance) have
resulted in little success in the return of the
bald eagle to the Lake Ontario shoreline. The
eagles have been more successful inland from
the Lake.
The problem of persistent toxic contaminants in
the Lake led federal and provincial/state
governments to develop the Niagara River
Toxics Management Plan (NRTMP). Following
STATE OF THE GREAT LAKES-1995
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51
this, the Lake Ontario Toxic Management Plan
(LOTMP) was developed. These plans were
developed to reduce the loadings of
contaminants into Lake Ontario.
The most significant sources of toxic chemicals
in Lake Ontario are considered to be the
Niagara River (which also includes the entire
Great Lakes drainage basin upstream of the
Niagara River); inputs from the ten other major
tributaries; non-point sources (including
surface water runoff and atmospheric
deposition); and inputs from point sources
(municipal and industrial facilities discharging
directly into the Lake). Since the Niagara River
constitutes nearly 85% of the tributary flow into
Lake Ontario, and since it is heavily
industrialized, it is a significant source of most
of the toxic chemicals entering the Lake.
The LOTMP is currently being expanded into a
more ecosystem based LaMP to protect the
Lake and to focus on restoring beneficial uses.
This will be achieved using indicators, that are
representative of a healthy self-sustaining
ecosystem, to identify the pollution problems
and to further determine the areas of degraded
quality. Fish community objectives for the
Lake have been developed, but continue under
review based on public comment. These
objectives will be used as one component of
the overall suite of environmental objectives for
the LaMP.
7.6 THE CONNECTING CHANNELS
Connecting channels are often the most
heavily utilized by humans, therefore all
five of the connecting channels have impaired
habitat. Part or all of each connecting channel
has been designated as an AOC (as discussed
in each lake section and shown in Table 12).
In addition to the impacts of agriculture,
industry and urbanization (which also affect the
Lakes), the connecting channels suffer from
physical alterations for shipping, water level
management and power generation causing a
loss of wetlands and rapids habitat.
8. MANAGEMENT CHALLENGES FOR THE
FUTURE
As discussed in this report, the health of the
Great Lakes ecosystem is variable. In
Lakes Huron and Superior which are less
urbanized and industrialized, water quality,
aquatic communities and habitats are relatively
healthy; in the other lakes, human activities
have caused widespread environmental
degradation. Even in the more disturbed
Lakes, though, progress has been made in
halting or undoing the damage caused by past
unsustainable practices. The water is cleaner;
loadings and levels of persistent toxic
chemicals have been reduced from the those
seen in the 1970s, and the nutrient control
programs instituted in the 1970s have largely
achieved their objectives. Phosphorus
loadings are much reduced and nuisance
blooms of algae are no longer a problem. In
fact, success in reducing phosphorus loadings
under the GLWQA has provided a binational
resource management model to the world.
Awareness of the fragility of the ecosystem is
now widespread throughout the basin. Fish
and wildlife communities are healthier than
they were twenty years ago with some native
(indigenous) top predators undergoing a
resurgence, and some progress being made to
protect and enhance aquatic habitat. Citizens
have been galvanized into action over the past
20 years, and action at state/provincial and
local levels to conserve and restore important
STATE OF THE GREAT LAKES-1995
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52
CONNECTING CHANNELS
Area of Concern
St. Marys River
St. Glair River
Clinton River
Detroit River
Rouge River
Niagara River (Ont)
Niagara River (NY)
St. Lawrence River (Cornwall, Ont)
St. Lawrence River (Massena, NY)
IMPAIRMENT CATEGORY
Ecological Health
UDMD
DIDDBM
MID
DID DID
nun
mmsmam
BflDDlEI
BflH
EHBDHH
Habitat
Human Health
a
a
Human Use
DHDBD
ฎm*mm
DBDBD
amn
DBDBD
QUOD
rJBDDD
BHHM
nnaaa
= Impaired Use
EH = Likely, Suspected, Under Assessment or Unknown Impairment
a = No Impairment
ฉ = Restored Use
For a more complete breakdown of impairments see Table 6
Table 12. Areas of Concern for the Connecting Channels
ecosystems is now occurring through the RAP
process and other domestic initiatives.
It must be recognized that there is still a long
way to go to restore the Lakes to a healthy
state, despite the progress that has been made
in the last twenty years. Society is moving
many may argue, too slowly to embrace the
principles of sustainability, waste reduction,
pollution prevention, and resource efficiency.
However, the Lakes are besieged with
pollutants released hundreds, or even
thousands, of miles away from the basin, and
locally pollutants are still being discharged into
air, soil and water by individuals, municipalities,
industries and agriculture. Persistent
contaminants continue to cycle through the
ecosystem affecting fish and wildlife, and the
effects of long term exposure to small
concentrations of contaminants continue to be
discovered. Aquatic habitat loss has been
slowed, but it continues to take place on an
unacceptable scale. Exotic species continue to
destabilize aquatic communities, degrade
habitat, and alter the cycling of nutrients and
contaminants.
The complexity of the ecosystem and the
intricacy of interrelationships pose tremendous
challenges for managers in the 1990s. How
STATE OF THE GREAT LAKES-1995
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53
well these, and other challenges are met will
define the condition of the Great Lakes for
future generations. These challenges include:
The challenge of adequate information:
This report, and the background papers on
which it is based, cite numerous examples of
areas in which research and data collection
need to be done. In many cases, however, the
amount of research necessary is overwhelming
relative to the resources available. Some
priority research needs include data on the
quality and quantity of aquatic habitat,
information on atmospheric transformation and
deposition to aid in the determination of
pollutant loadings to each of the Great Lakes,
information on contaminant cycling, a better
understanding of food web dynamics, spatial
and temporal data on humans and aquatic
biota, and basic economic data on the Great
Lakes basin. Effective steps forward require
good information on stresses, interactions and
effects on which to base decision-making. It is
vital to fill these priority data gaps.
The challenge of information management
and communication: Information on
environmental conditions is possessed by
hundreds of boards, agencies, commissions,
and interest groups in the basin. But all too
often this information is not readily available.
Moving forward to restore ecosystem health
will require taking advantage of the
tremendous strides made in computer
networks, integrated information, cable, and
other telecommunication opportunities to
improve communication on environmental
issues. Effective communication is key in
transferring scientific knowledge to the policy
makers in a useful and understandable
language. For this to happen the data must
first become consolidated, standardized and
accessible.
The challenge of how decisions are made:
Traditional decision-making is linear. A
decision is made by an individual or agency, it
is passed along for review or approval by a
long "chain of command." This is time-
consuming, compartmentalized, and
antithetical to the ecosystem approach. The
ecosystem approach requires "round table",
interdisciplinary, inter-jurisdictional and
intersectoral approaches to decision-making,
approaches which aim for consensus among
stakeholders often at the local level. The
ecosystem approach to decision-making is at
work in the LaMPs and RAPs programs.
The challenge of institutional
arrangements: The goal of restoring and
maintaining the integrity of the Great Lakes
basin ecosystem poses many challenges to
institutional structures. Each agency has its
own goals, objectives and mandates, which are
not necessarily those that are best for the
ecosystem. The emphasis for management of
the Great Lakes has gradually shifted from
traditional approaches to pollution control in a
single medium, such as air, water or
sediments, towards an ecosystem approach
where agencies examine the combined
impacts of a variety of stressors on the
environment. This requires recognition of
ecosystem impacts from all decisions and
recognition of effects beyond the narrow
purposes of specific laws, regulations or
organizational missions. It also requires a
consensual "buy in" to goals, objectives and
strategies from federal, state, provincial,
regional and municipal governments, and from
the private and non-governmental sectors.
Because of the complexity of the Great
Lakes basin ecosystem, and the complex
nature of the problems it faces, partnerships
STATE OF THE GREAT LAKES-1995
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54
Sand dunes on Lake Michigan
and coordination of actions are key to
implementing an ecosystem approach to
management.
The challenge of dealing with biodiversity:
Recognition of the need to protect genetic
resources and the habitats needed to sustain
various species, genetic variety within
populations, and biological communities poses
new challenges and requires different
perspectives that fit well within the ecosystem
approach. Related challenges are whether
programs can be adapted to supply the
information needed to address the issue, and
whether effective strategies to protect
biodiversity can be developed. As discussed in
this report some of the greatest stresses on
biodiversity result from habitat destruction,
over-exploitation of resources, and competition
from non-native species.
The challenge of agreeing on endpoints for
restoration: Since some of the genetic
diversity and physical features of the system
have been irrevocably lost, and some exotic
species appear to be permanently established,
how can physical, chemical and biological
integrity be defined? What measurable
conditions should programs seek to attain?
Objectives for restoration of the physical,
chemical, and biological integrity of the
ecosystems of the Great Lakes are just now
being developed. However, the historical
benchmark (ie. the post-glacial state of the
Great Lakes ecosystem) remains an important
reference point with which to judge the extent
STATE OF THE GREAT LAKES-1995
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55
of degradation of Great Lakes ecosystems and
the prospects for various levels of restoration.
Jurisdictions around the Great Lakes are now
faced with decisions regarding the restoration
of the aquatic communities in the Lakes, and
the composition of those restored communities.
Justification of preferences for a particular
community structure may be aided by historical
analysis, but an alternate structure, with non-
historical species performing the same
ecological function, is also possible. One
expression of this is to manage towards pre-
settlement conditions, recognizing that these
conditions will never be fully attained. The
decision about which ecological community
becomes the objective of restoration efforts is
a matter of social preference and how much
they are willing to pay to achieve their
objectives. Scientific advice should contribute
to an informed decision-making process. Lake
Erie provides us with a good example. The
historic ecosystem of Lake Erie no longer
exists, and is unlikely ever to exist again. The
ecosystem is more fragile now and the goals
must be redefined based on the impacts of
zebra mussels, loss of habitat and
contaminants. The major shifts in the
biological community structure make
predictions about the future status of the
ecosystem highly uncertain.
While it is important to define benchmarks and
to achieve societal consensus on the desired
endpoints for restoration, managers must also
know when it is best to act on behalf of the
lake. Again using Lake Erie as an example,
during the mid-1980s when water levels on the
Lake were quite high and damage to shoreline
properties occurred with every storm, the
public wanted regulated water levels.
Managers were able to convince them that it
was better for the ecosystem to regulate its
own water levels.
The challenge of dealing with a focus on
places: Applying an ecosystem approach to
restoring and maintaining the Great Lakes
basin ecosystem requires a recognition of the
extent to which natural systems vary from
place to place, and how local systems relate to
those around them. Traditional environmental
regulations and programs have used blanket
objectives and standards, used on a national,
provincial or state-wide basis. One of the
challenges for governments and other
stakeholders is to understand and address
restoration with respect to local ecosystems
(both structure and function) and their linkages
elsewhere.
The challenge of subtle effects of toxic
substances on people and wildlife: The
subtle effects of long term exposure to small
quantities of toxic substances poses a
challenge to managers as well as to
researchers. If some substances have effects
at such low concentrations that the ecosystem
has virtually no ability to absorb them, or the
global environment already contains
concentrations at levels that may be causing
adverse effects, how can use or generation of
them be avoided or prevented?
The challenge of connecting decisions with
ecosystem results: A major part of the
challenge is to understand ecosystem
problems and the stresses that cause them.
Another important aspect of the challenge is
establishment of well defined ecosystem
objectives and indicators to measure success
STATE OF THE GREAT LAKES-1995
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56
in restoring and maintaining ecosystem
integrity. Such indicators can provide a focus
for bringing together seemingly disparate
programs and serve as a basis for integrating
programs that were originally created to deal
with separate aspects of enviromental quality,
resource management or other purposes.
However, it must be remembered that because
of the complexity of the ecosystem, outcomes
can never be predicted with absolute certainty,
and can often be entirely unpredictable.
The challenge of sustainability: Restoration
and protection of the Great Lakes ecosystem
requires a commitment to achieving
sustainability. As a society, we still deplete
non-renewable resources, still spend our
environmental "capital." A truly healthy Great
Lakes ecosystem will be one in which the
consideration of the environment and the
economy will be integrated with the social
needs of humans in a balanced and
sustainable manner. The Great Lakes basin
and surrounding region face a future filled with
opportunities as well as uncertainties. A
sustainable development course will require
new measures to enhance economic growth as
well as institutional mechanisms among public
and private sectors designed to foster
cooperation and coordination in environmental
protection. There is a continued need on the
part of governments and industry to prevent
pollution problems before they arise.
development", defining it in terms of a way of
life that meets the needs of the present without
compromising the ability of future generations
to meet their own needs. This in turn clearly
requires prudent management of resources
including maintaining the integrity of
ecosystems.
The concept received global recognition and
support in the 1992 United Nations Conference
on Environment and Development. Following
the conference individual countries, including
Canada and the U.S. have identified
sustainable development as a goal and taken
various steps to attain it.
In 1991 the Chairman of the Council of Great
Lakes Governors described a vision of the
region as a world leader in natural beauty and
economic might. It is a vision that recognizes
that the restoration and protection of the Great
Lakes is dependent upon a world-class
economy. At the same time it recognizes that
the health of the Great Lakes is central to the
region's economic future. The vision also
recognizes that the region's industries will not
be competitive in the world economy, unless
they are world leaders in clean, sustainable
production.
The connection between the quality of the
environment and viability of economic systems
has been recognized by some for a long time,
but it was given new meaning and immediacy
in 1987. Our Common Future, the 1987 report
of the World Commission on Environment and
Development coined the term "sustainable
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