STATE OF THE LAKES ECOSYSTEM
CONFERENCE
INTEGRATION PAPER
DRAFT FOR DISCUSSION PURPOSES
SEPTEMBER 1994
Canada
USA
-------
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 LAKES ECOSYSTEM
CONFERENCE
INTEGRATION PAPER
Prepared for
SOLEC STEERING COMMITTEE
Paul Horvatin, Co-Chair
United States Environmental Protection Agency
Harvey Shear, Co-Chair
Environment Canada
Grace Wever, Council of Great Lakes
Industries
Danny Epstein, Environment Canada
Maureen Evans, Environment Canada
Jennifer Wittig, Environment Canada
Dieter Riedel, Health Canada
Mary Hegan, Health Canada
Neil Tremblay, Health Canada
Tim Eder, National Wildlife Federation
Fred Fleischer, Ontario Ministry of
Environment & Energy.
Kent Fuller, U.S. Environmental Protection
Agency
Philip Hoffman, U.S. Environmental
Protection Agency
Bob Beltran, U.S. Environmental Protection
Agency
Charlie Wooley, U.S. Fish & Wildlife Service
by
Joanna Kidd, LURA Group
Toronto
ENVIRONMENT CANADA
867 Lakeshore Road
Burtington, Ontario
L7R 4A6
For additional copies please contact:
ENVIRONNEMENT CANADA
867, rue Lakeshore
Burlington. Ontario
• . L7R 4A6
ENVIRONMENTAL PROTECTION AGENCY
Great Lakes National Program Office
77 West Jackson Blvd.
Chicago, Illinois 60604
U.S.A.
EPA 905-D-94-002 Integration Paper - October 1994
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TABLE OF CONTENTS
Executive Summary 3
1.0 Introduction 5
2.0 Ecosystem Concepts and the Ecosystem Approach 9
3.0 The State of the Ecosystem 12
3-1 The State of Aquatic Communities 12
3.2 Human Health and the Effect of Environmental Contaminant Stresses ... 14
3.3 The State of Aquatic Habitat IS
3.4 Nutrient Stresses 16
3-5 Persistent Toxic Contaminant Stresses 17
3.6 Economic Stresses and Mitigating Activity 19
3.7 Overall Health of the Great Lakes Basin 20
4.0 Major Stresses and Their Interactions 24
4.1 Major Stresses on Aquatic Communities 24
4.2 Major Stresses on Aquatic Habitat 28
4.3 Major Environmental Contaminant Stresses on Humans 30
4.4 Key Interactions Among Stresses 32
5.0 Management Challenges for the Future 39
Appendix A: 400 Years of Change 42
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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LIST OF TABLES AND FIGURES
Table 1: Preliminary Indicators of Ecosytern Health 21
Table 2: Summary of Fish Species Lost or Severely Diminished
in the Great Lakes 25
Table 3: Priority Contaminants of the Great Lakes , 27
Figure 1: The Laurentian Great Lakes Basin '....6
Figure 2: Dioxin Concentrations in Herring Gull Eggs 18
Figure 3: Primary Biophysical Stresses on the Great Lakes Ecosystem and their
Linkages , , , 33
Figure 4: Contaminant Cycling in the Great Lakes Ecosystem 36
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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EXECUT|VE SUMMARY
The central purpose of the United
States/Canada Great Lakes Water
Quality Agreement is the restoration and
maintenance of the chemical, physical
and biological integrity of the Great
Lakes Basin Ecosystem. In support of this
purpose the governments are sponsoring
a State of the Lakes Ecosystem
Conference (SOLEC) to review and make
• available information on the state of the
system. A major purpose of the
conference is to support better decision-
making through improved availability of
information on the condition of the living
components of the system and the
stresses which affect them. This paper
'undertakes to integrate the main themes
of six working papers prepared as
background for the conference.
The Great Lakes Basin comprises one
of North America's major industrial and
agricultural regions. It is an area that is
rich in natural resources, linked by a .
strong transportation system, and host to
a vibrant and growing tourism and travel
sector. But the economic gains of the
Basin have not been without environ-
mental cost. The biophysical ecosystem
in the Basin has been and continues to
be subjected to a host of stresses —
resource extraction, urbanization, defor-
estation, industrial practices, nutrient
loading, introductions of exotic species,
alterations and destruction of natural
areas, the contamination of air, water and
soil and others. Further historic perspec-
tive is provided in Appendix A,
The condition of the living compo-
nents 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 impair-
ments, are also the most meaningful
indicators as far as the public is con-
cerned, i.e. can we swim, fish and drink
the water? Although effects on the living
system are the ultimate indicators, mea-
sures of the physical, chemical and bio-
logical stresses that affect the system are
equally important in describing the state
of the Lakes arid providing vital informa-
tion for programs that restore and protect
the integrity of the ecosystem.
Indicators are used to measure the
state of living components in terms of
both aquatic communities and human
health, although human health is mea-
sured primarily in terms of risks rather
than direct health effects. Indicators of
the state of aquatic habitats reflect both
the condition of the living vegetative
component of habitat, and physical and
chemical components. Indicators are also
used to measure three categories of
stress: nutrients, persistent toxic contami-
nants, and economic activity.
For purposes of simplification, a small
number of indicators for each of the
background paper subject areas have
been chosen and are shown in this paper.
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
are rated in four categories: poor, mixed/
deteriorating, mixed/improving and
good/restored. The report draws on
information from a variety of sources up
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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to the year 1993. Indicators within each of
the six subject areas showed a mix of
conditions and are summarized in tables
beginning on page 21,
The paper concludes with a brief
section on challenges for environmental
resource managers and decision-makers
to consider in the future as they use
ecosystem information.
The integration paper is intended to
focus and aid discussion among SOLEC
participants. The SOLEC Steering Com-
mittee welcomes suggestions from
participants on how the paper can be
improved for post-conference use.
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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1.0 INTRODUCTION
>y almost any standards, the .
Laurentian Great Lakes Basin (see
Figure 1) is rich in resources. The Great
Lakes contain one-fifth of all the fresh
surface water resources 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 32.4
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, the Great Lakes
Basin ecosystem is under tremendous
stress from human activities. Past and
current industrial practices, nutrient
loading, resource extraction, urbaniza-
tion, 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 tip
out of balance. What is the state of the
Great Lakes Basin ecosystem? This report
tries to take a measure of that state.
Restoration and maintenance of
the chemical, physical and biological
"... this first SOLEC is concen-
trating on recent changes and
rates of change. It is recog-
nized that severe impacts have
occurred in the past, but the
need at this time is to address
current conditions, stresses
and rates of change."
integrity of the Great Lakes Basin Ecosys-
tem is the central purpose of the United
States/Canada Great Lakes Water Quality
Agreement (GLWQA). Restoration and
maintenance can only be achieved with
widespread support and action on the
part of governments, industry, non-
government organizations and the gen-
eral public. To support this purpose the
governments are sponsoring a State of
the Lakes Ecosystem Conference
(SOLEC).
A major purpose of
the conference is to
support better deci-
sion-making through
improved availability of
accurate, ecosystem-
based information on
the condition of the
living components of
the system and the
I stresses which affect
them.
Specifically, the conference will:
• provide information on the state of
the Great Lakes ecosystem;
• develop support for an integrated
system which compiles and distributes
environmental information to assist
management plans and programs in
the Great Lakes Basin;
• provide information on existing Great
Lakes management strategies; and
• provide a forum for improved commu-
nications and network-building within
the Basin.
STATE OF THE LAKES ECOSYSTEM CONFERENCE • I NT EG RAT I ON PAPER
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The Great Lakes Basin
Great Lnkes Profile
O
O
in
-<
in
2
O
O
z
z
n
o
70
O
z
TJ
-o
m
70
SI MifyKivci
(.Snolockl)
Mull riikj(u
SI Clan Kiv«
UkcSl I'Uu
Dclfuil Klvci
MINNI-SOTA
N
Aren of Avci aye Voluuiv
kk&4uu2) Ucutk(iu) (kui3) Iiuii (yis)
Superior 82100 147 12100 I'JI
Michigan 57800 85 4020 99
Huron 59600 59 3540 22
Erie 25700 19 484 2 (>
Ontario |g>J60 86 1640 6
-75 0
300km
Source: Knviioilinvilliil Cunsciv.ihoii lirauch, I'liviioiinicnl C.ui.
FIGURE I: THE LAURENTIAN GREAT LAKES BASIN
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In the interest of focusing attention
on decisions that affect the Lakes and
gaining wider recognition of the need to
consider impacts on the Lakes, this first
SOLEC is concentrating on recent
changes and rates of change. It is recog-
nized that severe impacts have occurred
in the past, but the need at this time is to
address current conditions, stresses and
rates of change.
As European settlement began almost
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 sub-
stances and human pathogens, the Lakes
today are severely degraded.
However, some recovery has been
made. Most Great Lakes observers would
agree that vast improvement has been
made in water quality through the con-
trol of nuisance conditions, nutrients,
human pathogens, and biochemical
oxygen demand. Also most observers
would agree that much progress has been
made in controlling toxic contaminants,
although much remains to be done. On
the other hand, although some progress
is being made on protecting and restor-
ing habitat, losses far exceed gains. In the
case of biological diversity, because each
loss of genetic diversity is permanent, all
losses are additive. Thus while some
progress can be made in reducing losses,
overall losses of native species and ge-
netic strains will continue faster than
that expected in the absence of human
activity.
The long-term losses in biodiversity
have been severe, as reported in the
working paper on Aquatic Community
Health. Similarly, losses in habitat have
been severe, as reported in the paper on
Aquatic Habitat and Wetlands. For both
aquatic community health and habitat,
while increasing efforts are being made
and losses in biodiversity and habitat are
slowing, the low point has probably not
yet been reached. 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 endangered
species and the ecosystems necessary to
support them. Unfortunately each genetic
loss is permanent, at least in the time
scale of the lives of humans and human
civilizations.
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 waterborne diseases.
Now the risk of such illnesses from
pathogens is slight.
While the health of the Great Lakes
basin ecosystem declined steeply, the
health of the human population seems to
have improved dramatically, as measured
in longevity, or in the incidence of fatal
or crippling infectious diseases such as
poliomyelitis or typhoid fever. However,
much of that improvement in human
health is due to improvements in sanita-
tion, to the development and use of
vaccines, and to drinking water disinfec-
tion. All of these measures have helped
to keep the incidence of severe outbreaks
of infectious diseases at a low level. On
the other hand, there have been slow, but
steady increases in the incidence of
certain cancers and of some respiratory
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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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 adverse effects of
environmental contaminants on human
health need to be investigated further.
This paper has been prepared as a
tool to assist managers and decision-
makers attending the Conference. Draw-
ing upon the most recent data available,
it evaluates the state of the Great Lakes
Basin ecosystem. It is hoped that the
Paper will focus discussion and spark
dialogue among participants about future
strategic directions.
This paper is based on. six "Working
Papers" prepared as background for
SOLEC which provide more complete
information on the following topics:
• health of aquatic communities;
• human health and health risks;
• aquatic habitat and wetlands;
• nutrients;
• toxic contaminants; and
• economy-environment linkages.
These Working Papers (provided
under separate cover) were developed by
binational teams with expertise in the
relevant issue areas. They provide an
account of current and historical condi-
tions in the Great Lakes Basin using a
variety of data sources compiled through
1992. They also identify data gaps, sug-
gest priority areas for action, and raise
important questions for debate.
This Integration Paper provides infor-
mation on ecosystem concepts and the
Great Lakes ecosystem and describes
briefly the changes that have taken place
during the last 400 years. It draws from
the information presented in the Working
Papers to assess the state of the Great
Lakes ecosystem today using a prelimi-
nary list of ecosystem health indicators.
The Paper identifies the major stresses
acting on aquatic habitat and aquatic
communities, and the major environmen-
tal stresses on humans living in the
Basin. Interactions among stresses are
explored briefly, and the Paper ends with
a number of management challenges for
the future.
As noted, the Integration Paper is
designed to focus and aid discussion
among SOLEC participants. The SOLEC
Steering Committee welcomes sugges-
tions from participants on how future
versions of the Integration Paper can be
improved.
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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2.0 ECOSYSTEM CONCEPTS AND THE ECOSYSTEM
APPROACH
Under the binational Great Lakes
Water Quality Agreement, an
ecosystem is defined as "the interacting
components of air, land, water and living
organisms, including humans," A number
of key ideas are embedded in this
concept. These include:
» Humans are part of the ecosystem,
and not separate from it.
* Ecosystems can operate and can be
defined at many different scales —
from global to local — forming a
hierarchy of systems
nested within sys- ( —
terns. The Great
Lakes Basin is an
ecosystem within
which are found *
five smaller ecosys-
tems — the Lake
Superior, Lake
Michigan, Lake
Huron, Lake Erie
and Lake Ontario
sub-basins. Within
these sub-basins are
found rivers drain-
ing watersheds, and within these
watersheds are found streams drain-
ing subwatersheds.
• Ecosystems are not closed systems.
Seeds, spores, animals, water, chemi-
cals and nutrients travel between
ecosystems or are carried by natural
processes and humans. The Great
Lakes Basin influences and is influ-
enced by the regions outside of it.
"Healthy ecosystems have
integrity ... but ecosys-
tems also have limits to
the stress they can en-
dure. Pushed beyond
their ability to absorb or
assimilate stress, ecosys-
tems can become de-
graded."
» Ecosystems are dynamic systems in
which change is normal and some-
times unpredictable. Over long peri-
ods of time, ponds and lakes age and
dry up, terrestrial vegetation under-
goes succession to reach climax
states, and communities adapt to
global changes in temperature. Eco-
systems can be changed dramatically
by natural episodes of fire, flood or
glaciation.
Healthy ecosystems have integrity —
the resilience to absorb or assimilate
external stresses. But
ecosystems also have
limits to the stress they
can endure. Pushed
beyond their ability to
absorb or assimilate
stress, ecosystems can
become degraded.
The multiple
stresses on Lake Erie
are an example. Habitat
destruction, sedimenta-
tion, over-fishing and
i nutrient enrichment all
contributed to a de-
cline of the fishery and a -shift in. species
composition. Excessive loading of nutri-
ents during the first half of the 20th cen-
tury lead to a proliferation of algae in the
Lake. The breakdown of dead algae by
bacteria used up much of the oxygen in
the bottom waters of the Central Basin,
leaving little for other aquatic life. Due to
lack of oxygen, mayflies and their
nymphs had vanished from large areas of
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INT EG RAT I ON PAPER
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Lake Erie, depriving fish species such as
perch, walleye, cisco and bass of a staple
food. This compounded the already
stressed stocks, severely depleted be-
cause of the stresses just mentioned.
In the case of the eutrophication of
Lake Erie, concerted, basin-wide efforts
to reduce phosphorus loadings brought
the ecosystem back toward balance
again, and aided the restoration of the
fishery, already on its way back because
of a fishing ban on walleye and whitefish
in the early 1970s. In some cases, how-
ever, ecosystem effects are irreversible.
While ecological restoration can be
achieved to some extent, the original
aquatic community in Lake Erie with its
total biodiversity and genetic diversity
within each species can never be recre-
ated. Ecosystem response time is also
variable. While surface water can respond
to a dramatic reduction in loadings of a
particular organochlorine contaminant
within a few years, it may take many
decades for an equivalent reduction to
take place in bottom sediments through
natural biological and physical processes.
Governments have traditionally ad-
dressed human activities on a piecemeal
basis, separating decision-making on
environmental quality from decision-
making on natural resource management
or on social or economic issues. Even
within the environmental field, agencies
have traditionally managed air issues
separately from those dealing with water,
land or wildlife. An ecosystem approach
to management is a holistic approach that
recognizes the interconnectedness of and
addresses the linkages occurring among
air, water, land and living things. An
ecosystem approach:
• includes the whole system, and not
just parts of it;
• focuses on interrelationships among
the components of the environment
and between living and non-living
things;
• includes consideration of the natural
environment, society and economy;
• is based on natural geographic units
such as watersheds;
• incorporates the concepts of
sustainability; and
• respects species other than humans
and generations other than the
present.
The application of the ecosystem
approach under the GLWQA has been
interpreted in many ways and debate will
undoubtedly continue as to how inclusive
the concept should be in terms of geo-
graphic and socio-economic aspects. In
terms of geographic extent, this paper
focuses on the conditions in the Lakes
themselves and rivermouth areas as
influenced by activities throughout the
Basin, and not on the conditions in
upstream and terrestrial areas. In terms of
socio-economic aspects, this report
focuses on the state of the biophysical
environment, not the state of the social or
economic environments. The report
considers human health only as it is
related to environmental stresses, and
does not consider economic health per se.
However, some major economic stresses
are considered to the extent that they
impact the biophysical environment.
The ecosystem approach and its
applications continue to evolve as better
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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indicators of ecosystem integrity are
developed and as management plans and
programs are reoriented to produce
environmental results measured in terms
of ecosystem objectives and indicators.
Remedial Action Plans for Areas of Con-
cern and Lakewide Management Plans are
leading examples.
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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3.0 THE STATE OF THE ECOSYSTEM
How healthy is the Great Lakes Basin
Ecosystem? What constitutes good
health? How can it be measured? The
system is clearly different than before
European settlement. To what extent has
the biological, chemical and physical
integrity been lost' What part of the
genetic diversity of the system has been
lost and how much remains? What
modified state of integrity is it possible
to attain? Many of these questions can
not yet be answered.
The biological state of the Lakes, with
the partial exception of Lake Superior,
has been unstable during recent decades.
What new diverse, self-sustaining, inte-
grated ar^d stable system can reasonably
be expected?
One way to determine the status of
the Great Lakes ecosystem is to measure
indicators of ecosystem health. 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. Ecosystem health
indicators measure ecosystem quality or
trends in quality that are useful to manag-
ers and scientists. Many attempts to
develop ecosystem health indicators have
been made or are underway in the U.S.,
Canada and internationally, including
those outlined in the Aquatic Community
Health working paper.
Because the current attempts to
develop indicators of ecosystem health
are not at stages where they can readily
be used in simple terms, the SOLEC
Steering Committee has developed its
own preliminary list of indicators (see
Table 1). The indicators selected include
those for: the state of aquatic communi-
ties, 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 important to
recognize that the economy also provides
the means to control stresses and restore
the system.
The SOLEC Steering and Technical
Committees rated the indicators based on
information collected for the Working
Papers. Rating was done in four broad
categories:
• poor, (meaning significant negative
impact);
• 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).
3.1 The State of Aquatic
Communities
Compared to their chemical, physical and
biological integrity 300 years ago, the
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Great Lakes ecosystems are extremely
unhealthy. The catastrophic loss of
biological diversity and subsequent
establishment of non-indigenous
populations is the most striking
indication of degradation of the Great
Lakes.
At least 18 historically important fish
species have become depleted or have
been extirpated from one or more of the
lakes. Amplifying this loss of species
diversity is the loss of genetic diversity of
surviving species. Prior
to 1950, Canadian j
waters of Lake Superior
supported about 200
distinctive stocks of
lake trout, including
some 20 river-spawning
stocks. A large number
of these stocks is now
extirpated, including all
of the river spawners.
The loss of genetic
diversity of lake trout
from the other Lakes is
even more alarming, with complete
extirpation of lake trout from Lakes
Michigan, Erie, and Ontario, and only one
or two remnant stocks in Lake Huron.
Accompanying this loss of diversity
was a series of invasions and introduc-
tions of exotic species. Since the 1880s,
some 139 non-indigenous species have
become established in the Great Lakes.
Together, the non-indigenous species
have had a dramatic and cumulative
effect on the structure of the aquatic
communities of the Great Lakes, and their
persistence poses substantial problems
for the restoration and maintenance of
native species associations.
"While aquatic communi-
ties in all the lakes have
been significantly dis-
turbed and altered by a
host of stresses... those in
Lakes Michigan and
Ontario are the most un-
stable."
The state of aquatic communities is
the ultimate test of whether prevention,
control and restoration programs are
effective. Three indicators for measuring
the health of aquatic communities were
selected. The first indicator — the num-
ber 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 due to the lower levels of devel-
opment, industry and
human population.
Even in the more
disturbed lakes, at-
tempts to reintroduce
depleted species of
native predator fish
such as walleye and
lake trout have been
partly successful.
The second indica-
tor, the Lake Trout
Dichotomous Key,
provides a measure of
how balanced the aquatic ecosystem is.
This key is based on scores of questions
relating to lake trout and their habitat.
Using this indicator, Lake Superior rated
as good/restored, Lakes Huron and Erie
as mixed/improving, and Lakes Michigan
and Ontario as poor. While aquatic com-
munities in all the lakes have been sig-
nificantly disturbed and altered by a host
of stresses (including over-fishing, exotic
species, habitat destruction, nutrient
enrichment and persistent toxic sub-
stances), those in Lakes Michigan and
Ontario are the most unstable. U.S. and
Canadian government stocking programs
to reintroduce lake trout and non-native
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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salmonid predators to the Great Lakes
have resulted in the development of
popular sports fisheries providing a
wide range of species for anglers. The
stability of fish communities and
fisheries, however, are not predictable
at this time.
The third indicator for the state of
aquatic communities is reproductive
impairment. This indicator is rated as
mixed/improving in all lakes. Exposure
to a variety of environmental stresses
including organochlorine compounds
(some widespread, some local) has
caused reproductive problems for Great
Lakes wildlife, especially aquatic birds. In
the 1950s and 1960s severe effects were
observed and populations of some spe-
cies declined, often due to thinning of
egg shells. In recent years the problems
are present in less obvious forms which
cause birth defects or failure to repro-
duce in a small percentage of the popu-
lations. Population problems were some-
times attributable to environmental
contaminants, but in other cases popula-
tions actually increased during times of
high contaminant loadings, e.g. ring
billed gulls. Reductions in loadings of
organochlorines have allowed popula-
tions of herring gulls, Caspian terns,
black-crowned night herons and double-
crested cormorants to become re-estab-
lished in the Great Lakes. Indeed, cormo-
rant populations have rebounded to
levels never seen before. Continuing low
rates of bill defects and other develop-
mental abnormalities were seen through
the 1980s in cormorant populations,
suggesting that the birds were still being
exposed to toxic amounts of PCBs and
other organochlorine compounds from
fish, particularly in "hotspots" such as
Green Bay. Wisconsin. It is worth noting
that the "background" frequency of defor-
mities, as determined from Western
Canada bird populations, does not differ
significantly from the frequency of defor-
mities in most areas of the Great Lakes,
except for a few of these hotspots.
While exposure of the aquatic com-
munity to most known toxic contami-
nants is declining, the effect of chronic
exposure to low concentrations of persis-
tent toxic substances remains uncertain.
3.2 Human Health and the
Effect of Environmental
Contaminant Stresses
Environmental contaminants are only
one category of factors that affect human
health. Other factors include nutrition,
adequate shelter, genetic makeup,
exposure to bacterial or viral disease
agents, lifestyle factors such as smoking,
drinking and fitness, social well-being
and others.
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 contami-
nants and human health; these are listed
in chapter 4.3.
Direct indicators of human health
include the incidence of birth defects and
cancer; longevity; children's body weight
and development; and incidence of infec-
tious diseases related to water sports and
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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drinking water. Indirect measures include
beach closures and fish consumption
advisories. Unfortunately, basin-wide
data for these measures are not available
at this time.
A number of indicators to measure
environmental contaminant stresses on
humans in the Great Lakes are proposed.
These include: water quality; air quality;
atmospheric and total radioactivity. Even
with measures of stress and exposure,
information on differences among basin,
national and global levels is limited. In
"... levels of priority con-
taminants ... in human tis-
sues of Great Lakes resi-
dents are similar to levels
found in human popula-
tions elsewhere...."
order to better assess the impacts of
environmental stresses on human health,
better trend data over time must be
collected on body burdens, exposures
and potential health effects.
Available information indicates that
levels of priority contaminants such as
PCBs, dioxins and furans in human tis-
sues of Great Lakes residents are similar
to levels found in human populations
elsewhere, suggesting that exposures are
also similar.
The overall rating for environmental
contaminant stresses from the Great
Lakes on human health in the Basin is
mixed/improving. Because little data
exist to measure impacts of contaminant
stresses on humans in the Great Lakes
over time, we use the levels of contami-
nants in me ambient environment and in
fish and wildlife and in human milk as a
surrogate. Based on this we can reason-
ably say that the stress from toxic con-
taminants on human health is likely to be
mixed or in some cases improving. This
rating reflects the general decline of
concentrations of persistent toxic sub-
stances in all media including fish
throughout the Great Lakes, and the fact
that the major route of human exposure
to contaminants in Great Lakes waters is
through fish consumption.
3.3 The State of Aquatic
Habitat
The first indicator selected for the state of
aquatic habitat and wetlands is the loss of
habitat (both in terms of quality and
quantity) which 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 the Lower Lakes
were aE 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
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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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
"Sixty percent of the origi-
nal wetlands in the Great
Lakes Basin States have
been lost since the 1780s;
in Ontario, south of the
Precambrian Shield, wet-
land losses have been es-
timated to be as high as
80%."
Lakes was rated as good/restored. Fewer
cold-water streams have been lost and
degraded in the Upper Lakes basins
because of the lower degree of urbaniza-
tion and human disturbance.
A second indicator — encroachment
and development of wetlands — was also
rated as poor. This reflects the continu-
ing loss and degradation of wetlands
basin-wide due to urban development,
recreational uses, agriculture and other
forms of encroachment.
The third indicator selected consid-
ered gains in habitat and wetlands
through protection, enhancement and
restoration efforts. There are various
international, national and state/provin-
cial 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 produc-
ing good results is the North .American
Wildlife Management Program which has
resulted in the protection of more than
17,500 hectares of wetlands in the Basin.
3.4 Nutrient Stresses
Four indicators to measure nutrient
stresses were rated. Three were rated as
good/restored. Two of these are total
phosphorus loadings (GLWQA targets
were achieved by 1991 in four of the five
Lakes) and total phosphorus concentra-
tions in open water (GLWQA objectives
were achieved by 1991 in all Lakes). A
third "good/restored" rating was given to
an indicator measuring the levels of
chlorophyll a in the Lower Lakes, which
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 goal set in
1972 of "reduction in the present level of
algal biomass to a level below that of a
nuisance condition."
The fourth indicator — levels of
dissolved oxygen in Lake Erie's bottom
waters — was considered mixed/improv-
ing. Oxygen levels in Lake Erie's bottom
waters are much better than they were
twenty years ago. Notwithstanding this,
and despite phosphorus loading reduc-
tions, periods of anoxia (lack of oxygen)
were still occurring from 1987 to 1991 in
the late summer in some areas of the
STATE OF THE LAKES ECOSYSTEM CONFERENCE • I NT E G RAT I ON PAPER
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Central Basin. This continued anoxia may
be attributable to the release of historical
phosphorus from bottom sediments, or. it
may be that intermittent anoxia is an
inherent property of Lake Erie's Central
Basin.
3.5 Persistent Toxic
Contaminant Stresses
To measure the effects of stress from
persistent toxic contaminants, 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
"...although large per-
'centage reductions. have
been achieved in compari-
son to peak levels, for
many contaminants, an
additional level of magni-
tude further reduction is
needed to reach accept-
able levels of risk."
of persistent toxic contaminants have
been reduced substantially since 1970
(see Figure 2 showing dioxin
concentrations in herring gull eggs from
1971 to 1992). 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 media such as open
'waters, sediments, fish and wildlife.
Levels of organochlorine contami-
nants in the tissues of top predator and
forage fish initially declined significantly
from the late 1970s to mid 1980s but have
shown a slower rate of decline recently.
Despite this overall trend, from 1986 to
1989, in some areas, particularly in Lake
Ontario, levels of some of these contami-
nants increased in some fish. On the
other hand, from the late 1970s to the
mid 1980s, concentrations of heavy
metals showed little change. Levels of
persistent toxic contaminants in some
fish species in some areas continue to be
high enough to restrict consumption by
humans.
One possible cause of these continu-
ing high levels is that contaminant con-
centrations in fish are influenced by
changes in food which varies in availabil-
ity and contaminant content. As a result,
changes in contaminant levels in fish may
be influenced by shifts in feeding behav-
ior by fish or elsewhere in the food web.
Overall, contaminant levels have
shown good response to control pro-
grams although the rate of response has
slowed. Although overall contaminant
levels have been substantially reduced
from peak levels, for many contaminants,
additional reductions (in the order of a
level of magnitude) are 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.
Chemical residues in herring gull
eggs have been monitored by the Cana-
dian Wildlife Service since 1974. All the
chemicals routinely monitored since then
(including PCBs, DDT/DDE, mirex, dield-
rin and HCB) have shown a statistically
STAT E OFTHE LAKES ECOSYSTEM CONFERENCE • INTE G.RAT ION PAPER
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2500-
2000-
I500H
«• 1000—I
ft
»«•#
a 500-
rinnnn
r~i n
71 '72 73 74 75 76 '77 78 79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92
YEAR
Data Source: Weseloh. 1993
FIGURE 2: DIOXIN (2,3,7,8-TETRACHLORO-DI-BENZO-DlOXtN) CONCENTRATION
{N HERRING GULL EGGS 1971-1992, EASTERN LAKE ONTARIO
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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significant decrease at more than 80% of
the sites sampled. Chemicals monitored
later in the program, such as oxy-chlor-
dane, 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.
3.6 Economic Stresses and
Mitigating Activity
Economic activity produces both stresses
on the ecosystem and the means to
address or mitigate them.
Ten economic indicators were se-
lected. Two of these were rated as poor:
infrastructure investment and loss of
agricultural land and urban development.
This rating reflects the continuing low
levels of government investment in basic
infrastructure (with the exception of
some $10 billion U.S. in sewage treat-
ment plant construction and sewer
system upgrades during the past two
decades), and the continuing trend to
urban sprawl.
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 Cana-
dian employment during this time period
grew at 15%, while employment in the
Canadian side of the Basin grew by only
6%. In recent years, personal income
growth in the Basin has slowed substan-
tially, reflecting the loss of manufacturing
jobs and increase in service sector em-
ployment. From 1970 to 1980, personal
"Strategies for a sustain-
able future must try to
correct the past imbal-
ance between the econ-
omy and the environment,
and apply ecosystem man-
agement principles and
sustainable development
policies in the future/*
income in the Basin grew by 140%; that
for 1980 to 1990 grew at only 83%. The
population of the Basin grew by less than
1% from 1970 to 1990, as compared to the
combined population of the U.S. and
Canada which grew by 22% over the
same period. While urban sprawl clearly
adds stress, population and economic
growth add stfess and also provide the
means to control both new and old stres-
sors.
Four indicators — pollution preven-
tion, adoption of a stewardship approach,
water conservation, and per capita en-
ergy use — were rated as mixed/improv-
ing, reflecting changing public attitudes
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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towards resource conservation and sus-
tainable 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. Rec-
ognition of economic-environmental
linkages in resource management and
protection is increasing throughout the
Great Lakes Basin. However, the leap
between the concept of sustainable
development and its application is a
formidable one.
3.7 Overall Health of the Great
Lakes Basin Ecosystem
Overall, the health of the Great Lakes
Basin Ecosystem is variable, depending
on the measurement used. By some
measures, the health is good/restored;
this is certainly so for the aquatic
community on Lake Superior. At the
other end of the spectrum, a number of
indicators show quite clearly that some
aspects of ecosystem health are poor.
These include habitat loss, encroachment
and development of wetlands, and the
imbalance of aquatic communities in
Lakes Michigan and Ontario. In between
the extremes, as we have seen, many
indicators are mixed, with some trends
improving and others deteriorating.
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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TABLE I-.PRELIMINARY INDICATORS OF ECOSYSTEM HEALTH
INDICATORS
STATUS OF INDICATORS
Poor Mixed/ ; Mixed/ Good/
Deteriorating Improving Restored
STATE OF AQUATIC COMMUNITIES
Native Species Loss (# of native species)
Lake Superior
Lakes Huron, Michigan, Erie & Ontario
2, • Ecosystem Imbalance (Late Trout Dichotomous
Key)
Lake Superior
Lakes Huron & Erie
Lakes Michigan & Ontario
3. Reproductive Impairment
Effects - all Lakes
Body burdens - all Lakes
HUMAN HEALTH AND ENVIRONMENTAL CONTAMINANT RISKS
Overall state
Air/water/soil/sediment contamination
• contamination trends (Or SO4, dust)
• hospital admission and death rates for
respiratory illness rates (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
Dashes indicate lads, of Strain-wide data
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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TABLE I: PRELIMINARY INDICATORS OF ECOSYSTEM HEALTH (continued)
INDICATORS
STATUS OF INDICATORS
Poor Mixed/ ; Mixed/ Good/
, Deteriorating! Improving Restored
STATE OF AQUATIC HABITAT AND WETLANDS
1 . Loss in habitat/wetlands quality & quantity
United States - Michigan Survey ; •
- other states •
Ontario - CWS coastal wetlands i •
- Brook Trout stream habitat
(Upper Lakes)
- Brook Trout stream habitat •
(Lower Lakes)
2.
3.
Encroachment/development Basin-wide
Gains in habitat/wetlands quality & quantity
Areas protected under the North American
Wildfowl Management Plan
'
Net effect
•
"
"
NUTRIENT STRESSES
1 . Total phosphorus loads
• targets achieved in 4 of 5 Lakes (1991)
2.
3.
4.
Total phosphorus intake concentrations
• objectives achieved in all Lakes ( 1 99 1 )
Lake Erie dissolved oxygen
(Central Basin hypolimnion)
Chlorophyll 3 (as indicator of nuisance algal
growth) in Lower Lakes
/
"
•
• .
CONTAMINANT STRESSES
1.
2.
3.
4.
Loadings
Residue in fish
Residue in birds (herring gulls)
Body burdens — all Lakes
I
•
•
' !
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TABLE I: PRELIMINARY INDICATORS OF ECOSYSTEM HEALTH (continued)
INDICATORS
STATUS OF INDICATORS
Poor Mixed/ Mixed/ Good/
: Deteriorating Improving Restored
ECONOMIC STRESSESAND MITIGATING ACTIVITY
Employment (manufacturing & other sectors)
2. Infrastructure investment (public & private
sectors)
3.
4.
5.
6.
7.
8,
9.
10.
Research & development (measures of
technological innovation)
'
Land-use and reuse changes (loss of agricultural
land & urban development)
Population growth and stability (compared to
other regions)
Pollution prevention (expenditures and results
- loadings/emissions/discharges)
Personal income (statistics)
Adoption of stewardship approach (public
& private sectors)
Water conservation (industry & per capita)
Energy use (per capita)
'
"
"
•
•
'
>
•
STATE OF THE LAKES ECOSYSTEM CONFERENCE • I NT EG RATION PAPER
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4.0 MAJOR STRESSES AND THEIR INTERACTIONS
4.1 Major Stresses on Aquatic
Communities
Great Lakes aquatic communities
continue to be exposed to a multiplicity
of physical, biological and chemical
stresses. In terms of importance, the
major stresses on aquatic communities
are:
• imbalances in
aquatic communities
and loss of
biodiversity due to
over-fishing and fish
stocking, and pres-
ence of exotic
species;
» degradation and
loss of tributary and
nearshore habitat;
« impacts of persistent toxic contami-
nants; and
« eutrophication in localized areas.
Imbalances in Aquatic Habitat 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.
The loss of biodiversity and concomi-
tant establishment of non-indigenous
"The loss of biodiversity
and concomitant estab-
lishment of non-indig-
enous populations in the
Great Lakes has been little
short of catastrophic/*
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.
Native top predators, once dominated by
lake trout, have been replaced by hatch-
ery-reared imports. Table 2 lists the many
species of Great Lakes fish that have been
extirpated or are se-
verely depleted due to
human activities,
mostly over-fishing.
What is not shown by
the table is the funda-
mental loss of genetic
diversity among surviv-
ing species.
Accompanying (and
sometimes accelerat-
ing) this loss of diver-
sity was a succession of invasions and
deliberate releases of exotic aquatic
species. Some 139 non-indigenous
aquatic species have become established
in the Great Lakes since the 1880s. Spe-
cies that have established substantial
populations include: sea lamprey; ale-
wife; smelt; gizzard shad; white perch;
carp; brown trout; chinook, coho and
pink salmon; and rainbow trout. To this
list can be added more recent imports
such as the zebra and quagga mussel,
ruffe, rudd, fourspine stickleback and
others, and plant species such as purple
loosestrife. Together, these species have
had a dramatic and cumulative effect oh
the structure of aquatic communities in
the Great Lakes. The continuing pres-
ence of these non-indigenous species
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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TABLE 2. SUMMARY OF FISH SPECIES LOST OR SEVERELY DIMINISHED BY LAKE INTHE GREAT
LAKES. AN ASTERISK (*) INDICATES STOCKING PROGRAMS EXIST TO ATTEMPT RE-
INTRODUCTION. STATUS CODES ARE I (DEPLETED), 2 (EXTIRPATED), AND 3 (EXTINCT).
Common
Lake sturgeon
Longjaw cisco
Lake herring
Lake whitefuh
Bloater
Deepwater cisco
Kiyi
BJackfin Cisco
Shortnose cisco
Shortjaw Cisco
Burbot
Fourhorn Sculpin
Emerald shiner
Atlantic salmon
Lake trout
Sauger
Blue pike
Species Name
Adpenser ffuvescens
Cortgonus o/penoe
C. arttdii
C. c/upecformis
C. hafi
C. johannae
Ckjyi
C. n/gnp/nn;s
C. reighardi
C. zenitWcus
Low Jots
Myoxoccphalus quadricomis
Notropis otheirinofdes
Salmo sator
Saivelinus namayaish
Stizostedion canadcnse
5, vftreum gtaucum
Lake
Superior
1
"
1
1
2
1
Lake
Huron
1
2
2
*
2*
Lake
Michigan
1
2
I
'
2
2'
2
\
.
2
2
2*
Lake Lake
Erie Ontario
I 1
2
2
1
2
!
! 2
; 2
i i
;
1
3
I
2*
2* 2*
2
3 ; 3
poses substantial problems for the reha-
bilitation and maintenance of native
species associations.
Habitat Degradation and Loss
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 Superior, stocking of predators
obscures the effects of degraded habitat:
the lack of spawning areas, for example,
becomes less obvious. In highly polluted
areas of the Great Lakes, fish
communities may have already
compensated for these effects by
restructuring and eliminating tributary-
dependent stocks. Lack of basin-wide
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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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.
Persistent Toxic Substances
Persistent toxic contaminants have
had an impact on fish and wildlife species
in the Basin. Observed effects include
alteration of biochemical function, patho-
logical abnormalities, tumors, and devel-
opment and reproductive abnormalities.
Recent studies have suggested that estro-
genic effects of some organochlorines are
implicated in developmental abnormali-
ties in wildlife species. A possible conse-.
quence of the above effects is a decrease
in fitness of populations. In fish, how-
ever, it is difficult to link cause (i.e.
exposure to one or more toxic contami-
nants) to effects. There are some labora-
tory studies and evidence by association
that tumors 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 con-
taminants see Table 3.
Various studies have identified con-
taminant-associated effects on 11 species
of wildlife in the Great Lakes. Affected
species include fish-eating mammals
(mink and otter), reptiles (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
terns). All of these but the ring-billed gull
and otter showed historical evidence of
reproductive impairment due to contami-
nants. Populations of fish-eating birds
declined dramatically throughout the
1960s and 1970s as a result. With the
reduction in loadings of persistent toxic
contaminants such as PCBs, most of these
bird populations recovered. The repro-
ductive success of breeding eagles eating
Great Lakes fish remains lower than that
of those nesting inland. However, recov-
ery of the bald eagle to pre-1950 levels is
likely limited by the absence of appropri-
ate habitat, and may be limited by food
supply. Substantial parts of the Lake Erie
shoreline, and substantial portions of the
shorelines of Lakes Ontario, Michigan
and Huron are not suitable habitat for the
bald eagle because of agriculture, urban
sprawl and human disturbance. As indi-
• cated in chapter 3-0, continuing low rates
of bill defects and other developmental
abnormalities were seen through the
1980s in cormorant populations, suggest-
ing that the birds were still being ex-
posed to excessive amounts of PCBs and
other organochlorines from fish, particu-
larly in "hotspots" such as Green Bay,
Wisconsin.
Eutroph/cot/on
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 moderate impact on
aquatic communities. This is particularly
of concern in coastal marshes and inland
wetlands. Nutrient enrichment causes
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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TABLE 3: PRIORITY CONTAMINANTS OF THE GREAT LAKES
CHEMICAL
REFERENCE
Aldrin
Benzo(a)pynene
Chlordane
Copper
DDT and metabolites
Dieldrin
Fyran
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Alkylated Lead
a Hexachlorocychlohexane
8 Hexachlorocyclohexane
Mercury
Mirex
Octachlorostyrene
Polychlorinated biphenyls
2,3.7,8-TCDD (dioxin)
Toxaphene
References:
1,5.7
1,3,5,7,8
1,2,3,6,7
1,2,3
1,2,3,5,6,7
i,2,3,6,7
1,3,5,7
1,2,3
1,3
1,2,3,5,6,7
1,3,4,5,7
1,3.8
1,3,8
1,2,3,4,5,6,7
1,3.5,7
1,3,6,7
1,2,3,5,6.7
1,2,3,5,6,7
1,2,3,5,6,7
I = GLWQAAnnex I, list I (173 total pollutants in lift)
2 = GLWQI guidance list of 33 pollutants
3 = LAMPS critical pollutants lists (Laic Michigan 15 total, Lake Ontario 9 total)
4 = Pollution Prevention (IndustrialToxics Project, 17 total)
5 - Eleven Critical Pollutants (1985 1JC Report)
6 = Lake Superior Binational Initiative (9 total)
7 = Canada-Ontario Agreement Tier 1 list of 13 virtual elimination contaminants
8 = Canada-Ontario Agreement Tier 11 list of 26 (including !
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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excess growth of algae which depletes
the water column of oxygen needed to
sustain other forms of aquatic life.
4.2 Major Stresses on Aquatic
Habitat
Wetlands, tributaries, connecting
channels, open lakes and nearshore 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.
A number of differ-
ent classification sys-
tems exist for aquatic
habitat. For the pur-
poses of this paper,
habitats can be divided
into the following
types:
• open-lake;
i
• inshore (including
coastal wetlands, rocky shoals, shel-
tered bays and estuaries);
• shoreline (including sand dunes,
beaches, gravel shores and
lakeplains);
• tributaries (those rivers and streams
that drain into the Great Lakes);
• connecting channels; and
• inland habitats (including fens, bogs,.
marshes, wet meadows, ponds and
lakes).
Aquatic habitats function in many
important ways. They play a vital role in
nutrient cycling, uptake and transfer.
"Physical alteration of
aquatic habitat has been
the greatest cause of habi-
tat loss in the inland,
shoreline and inshore
zones of the Great Lakes."
They are among the most productive of
systems in terms of the growth of photo-
synthetic organisms (the assimilation of
energy by plants). Aquatic habitats help
to maintain water quality and regulate
water flows and levels. They play impor-
tant, sometimes very specific roles in the
life cycles of mammalian, aquatic and
avian species, providing habitat for
spawning, nesting, rearing, foraging and
sheltering. Aquatic habitats provide a
significant proportion of the total
biodiversity of the Great Lakes Basin
Ecosystem. Amongst all types of aquatic
habitats, the inshore
j zone (and its wetlands)
ranks highest in terms
of performing these
functions.
Basin-wide data on
the quality and quan-
tity of aquatic habitats
are scarce and frag-
mented, and the best
information that exists
is for wetlands. A U.S.
National Wetlands Inventory is now being
developed which will map wetlands
survey information, now only broken
down by state or province, on the basis
of drainage basins. Environment Canada,
in cooperation with other agencies and
groups, is gathering habitat-related infor-
mation through a number of programs.
Notwithstanding these initiatives, quanti-
fying habitat status remains largely de-
scriptive and anecdotal, and there are no
accepted basin-wide classification sys-
tems that integrate all aquatic habitat
types and allow habitat health to be
easily measured.
The major stresses acting on aquatic
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • I NT EG RATION PAPER
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habitat in the Great Lakes can be divided
into five categories. In terms of impor-
tance (i.e. magnitude of effect) these are:
* physical alteration (filling,
channelization, dredging,
bulkheading, etc.)
* hydrological changes (alterations in
water levels and flows, loss of connec-
tivity)
* physical process changes (tempera-
ture changes, sedimentation)
• biological changes (addition of exotic
species)
* chemical changes (addition of nutri-
ents, persistent toxic substances)
Physical alteration of aquatic habitat
has been the greatest cause of habitat
loss in the inland, shoreline and inshore
zones of the Great Lakes, Such alterations
as lakefilling in urban areas, dredging,
building dock walls in harbors, and the
channelization of rivers eliminate the
highly productive shallow water habitat
that is particularly crucial to forage fish
species and wading birds. Filling and
draining of wetlands for agricultural or
urban use eliminates not only the habitat,
but the invertebrate, fish and amphibian
populations living in that habitat. The
development of shorelines and riverbanks
for private docks, cottages and housing,
and the buildihg of bridges usually can
degrades nearshore habitat.
Hydrological changes can have
serious effects on inland wetlands, tribu-
taries, inshore and shoreline habitats.
Alterations in levels and natural fluctua-
tions of the Great Lakes can have severe
impacts on coastal marshes by flooding
out or drying up vegetation. Unnatural
stream flows can be caused by poor
stormwater management which causes
flushing of vegetation, sedimentation and
erosion. Overconsumption of groundwa-
ter leads jto reductions in base flows in
streams, so that insufficient water is
present for fish spawning. Wetlands
which are hydrologically disconnected
from their sources of water (e.g. coastal
wetlands cut off from a lake) will degrade
and dry up.
Physical process changes that can
affect aquatic habitat include temperature
changes due to the removal of bankside
vegetation, and increased sedimentation.
Temperature increases in a headwater
stream will eliminate habitat for cool-
water species such as brook trout. Sedi-
mentation covers fish spawning beds, ]
rendering them unusable, and suspended
sediment limits plant growth. Sediment-
laden river beds also provide ideal habi-
tat for sea lamprey (ammocoetes) in their
life cycle prior to becoming parasitic.
Biological changes have had a pro-
found effect on aquatic habitat in the
Great Lakes. The introduction of sea
lamprey, carp, purple loosestrife, zebra.
and quagga mussels, the ruffe and other
foreign species has had a significant
impact on aquatic habitats, but the scope
of the impact is not yet well-understood.
Both zebra and quagga mussels, for
example, eat organic detritus. In Lake
Erie, this has resulted in the extinction of
native Unionidae clams, and may be
contributing to declines in stocks of
smelt, yellow and white perch.
Chemical changes are moderate
threats to aquatic habitat. The major
chemical changes are excessive nutrients
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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and the presence of toxic substances.
Eutrophication continues to be a local-
ized problem in tributaries and inshore
habitats in many of the Areas of Concern.
Increased controls have reduced inputs
of toxic compounds from industries and
municipalities, but loadings continue
from urban and agricultural run-off and
releases from contaminated sediments
already in the system.
4.3 Major Environmental
Contaminant Stresses on
Humans
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 environ-
ment; 2) degree of
toxicity; 3) persistence;
and 4) ability to bio-
concentrate and
bioaccumulate. These
11 substances are listed
in Table 3 together with
several others identi-
fied for priority
consideration. While
these are L~~:~~
recommended for
priority consideration, there are
numerous other substances which must
also be considered due to 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 con-
taminants. The major route of human
exposure to PCBs, dioxins, furans, orga-
"While there is a large vol-
ume of scientific evidence
to show that these agents
are harmful, it is not cer-
tain how much harm they
are causing to the inhab-
itants of the Great Lakes
Basin."
nochlorine pesticides and certain heavy
metals is food consumption, particularly
consumption of contaminated fish. Food
is believed to contribute from 40% to
nearly 100% of total human intakes for
many of these substances. Studies of fish
eaters in the Great Lakes Basin have
shown a correlation between sport-
caught fish consumption and body bur-
den of PCBs and DDE in blood and
serum. Other routes of exposure include
drinking water, breathing contaminated
air, and dermal exposure. For contami-
nants other than toxics, 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 proto-
1 zoan Cryptosporidium
which has recently
caused intestinal prob-
lems, including some
deaths, due to its
presence in drinking
water.
Human populations
in the Great Lakes
basin, like those living
j elsewhere, are exposed
'. I to many toxic pollut-
ants 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 metals
and their compounds such as cadmium,
lead, and mercury. Other contaminants
include radioactive elements such as
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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radon and air contaminants such as
ozone.
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 inhab-
itants of the Great Lakes Basin. There are
several reasons for this uncertainty. *One
reason is the surprising scarcity of suit-
able 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 lack-
ing, 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 seek-
ing treatment for infectious diseases
caused by contaminated recreational or
drinking water, and on the number of
people admitted to hospitals for ill effects
caused by exposure to chemical environ-
mental 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 contami-
nants and to what, levels people are
exposed). A large number of contami-
nants occur at low concentrations, some
of which may gradually accumulate in the
body; others arc excreted without leaving
a trace, although they may have done
some damage.
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 (in-
cluding the inability, in some cases, to
obtain adequate sample sizes and
measurements that are suitably sensi-
tive and specific to detect changes);
« dose-response questions;
• accurate exposure assessment; and
» confounding variables that may hinder
research studies.
In the past, health researchers and
policymakers have tended to focus on
dramatic episodes accompanied by obvi-
ous health effects such as massive spills
of chemicals, or smog episodes, arid on
the most serious kinds of health effects
such as cancer. Recent scientific evi-
dence, however, based mostly on obser-
vations in animals, raises concerns that
exposure to low levels of certain con-
taminants 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,
so-called 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 so-called "weight of
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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evidence" approach which relies on
information from many sources, includ-
ing data on animals as well as humans.
This allows educated guesses to be made
which can then be tested through appro-
priate medical and scientific studies.
4.4 Key Interactions Among
Stresses
As outlined in Chapter 2, an ecosystem
can be defined as the interacting
components of air, water, land and living
organisms, including humans. While the
notion of the
ecosystem approach . :
has been embedded in
the GLWQA since 1978,
policymakers have only
relatively recently
begun to grapple with
actually using the
ecosystem approach in
planning. One of the
challenges of the
ecosystem approach is
that it requires a focus
on interactions and
linkages, as distinct '
from more traditional
environmental approaches in which
thinking tended to be
compartmentalized.
Because an ecosystem such as the
Great Lakes ecosystem is so complex,
understanding the interactions between
actions and effects is not easy. Like a
pond into which a stone is tossed, seem-
ingly innocent actions can have rippie
effects that are cumulative, indirect, and
far-reaching. Figure 3 is a simplified
diagram that attempts to illustrate some
of the linkages among major ecosystem
"One of the challenges of
the ecosystem approach is
that it requires a focus on
interactions and linkages,
as distinct from more tra-
ditional environmental
approaches in which think-
ing tended to be compart-
mentalized."
stresses and the environment. The dia-
gram illustrates only the biophysical
(natural) environment, and accordingly
does not include important social and
economic aspects of the ecosystem. It
shows the major linkages among three
components of the environment (human
communities, aquatic habitat and aquatic
communities) and three key stresses
(nutrients, toxic contaminants and exotic
species).
The figure shows the major activities
that cause stress on the Great Lakes
ecosystem. These include-, nutrient and
contaminant loading,
: introduction of exotic
species, over-fishing
and stocking, and
physical and hydrologi-
cal impairment,of
aquatic habitat. Physi-
cal impairment of
habitat includes
lakefilling, dredging,
channelization, defor-
estation, sedimentation
and other stresses.
!
| Hydrological impair-
ment includes loss of
hydrological connectivity and alterations
in water levels and flows.
As can be seen from Figure 3, not
only do these human activities put stress
on aquatic communities and aquatic
habitat, they also cause stress on human
communities. Discharging toxic contami-
nants into the environment, for example,
potentially exposes humans to these
contaminants through air, drinking water,
eating fish and other food grown within
the Basin, and swimming and other water
sports. This illustrates a fundamental
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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TOXIC
CONTAMINANTS
QUAUtY/ QUANTITY OF HABITAT
AQUATIC
COMMUNITIES
FIGURE 3: PRIMARY BIOPHYSICAL STRESSES ON THE GREAT LAKES ECOSYSTEM AND THEIR
LINKAGES
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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tenet of the ecosystem approach, one that
sets it apart from conventional environ-
mental planning — humans are part of
the ecosystem, not separate from it.
Loss of Aquatic Habitat
Figure 3 also shows how an
environmental problem such as loss or
degradation of aquatic habitat can have
many causes. Habitat loss and impairment
can be caused by a host of stresses —
physical alterations, hydrological
changes, the introduction of exotic
species, the presence of toxic
contaminants, high levels of nutrients and
changes in community structure. These
stresses can operate individually or in
concert. In practice, aquatic habitat in the
Great Lakes will usually be exposed to
more than one of these stresses. This
illustrates a fundamental aspect of
ecosystem health — because ecosystems
are so complex, effects are rarely caused
by only one stress.
Figure 3 also illustrates how one
"problem" can have many different con-
sequences. As an example, aquatic habi-
tat loss and impairment will have a direct
impact on the health of aquatic communi-
ties. Loss of spawning or foraging areas
for pike, for example, will directly affect
the ability of that species to survive lo-
cally, and will in turn affect forage fish
populations and other parts of the food
web. Habitat loss and impairment can
have negative impacts on human commu-
nities because of accompanying loss of
aesthetic and natural values, and reduced
opportunities for sport and commercial
fishing. Wetland loss and impairment, in
particular, contributes to higher loadings
of nutrients and contaminants in the
Great Lakes ecosystem because of de-
creased contaminant retention and
biodegradation. And these higher levels
of contaminants in the system will in-
crease the potential exposures to hu-
mans. This example illustrates the com-
plex interrelationships that lie at the heart
of the ecosystem approach: at first
glance, paving over a wetland seems far-
removed from increased human expo-
sures to contaminants, but the connec-
tions are indeed there. The next section
provides some more examples of the
many complex interactions and linkages
that characterize the Great Lakes ecosys-
tem and that challenge managers.
. Contaminant Cycling
One of the important linkages that is not
directly illustrated by Figure 3 is how
contaminants can move through the
Great Lakes Basin ecosystem (and into
the Basin from outside). The ecosystem
approach tells us that "everything is
connected to everything else." A PCB
molecule discharged into Lake Ontario,
for example, may not stay in solution in
the water. Once in Lake Ontario, the
molecule, can volatilize, in which case it
may be carried by air currents to fall out
in another lake or on land. Alternately,
once in the water, the molecule may bind
to a particle and settle to the bottom.
Here it can stay and eventually be
broken down by bacterial processes, or it
can be ingested by bottom-dwelling
organisms, in which case it can move up
the food chain when these organisms are
eaten. Even if the PCB molecule stays in
the water column, it can enter plankton
which are then consumed by pelagic or
benthic organisms which are in turn
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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consumed by forage fish. The forage fish
may in turn be eaten by a herring gull, or
by a large fish which may in turn be
eaten by a Great Lakes angler.
Another biological transfer that has
greatly increased in the last few years is
transfer of materials including contami-
nants from the water column to bottom
sediments by zebra mussels. The mussels
produce prodigious quantities of
pseudo-feces, undigested material which
they filter from the water and release to
bottom sediments. This has the potential
for a major shift in not only energy trans-
fers, but movement of contaminants as
well. This may at least partially account
for changes in contaminant trends being
observed in fish.
Figure 4 provides a simplified sche-
matic of contaminant cycling showing
various pathways. It also illustrates why
restoration strategies must be based on a
knowledge of the ecosystem.
Fundamental questions remain about
how contaminants move around the
Great Lakes ecosystem. What are the total
loadings of contaminants of concern?
What is the net effect on the Lakes of
atmospheric deposition and volatilization
of contaminants? How can we effectively
deal with long-range transport of con-
taminants from other countries and
continents? What is the relative contribu-
tion of historical sources (such as re-
leases from sediments) to levels found in
water and fish? What is the effect of zebra
mussels on contaminant cycling? Why are
contaminant levels in biota no longer
declining even though loadings of persis-
tent toxic contaminants have been
steadily reduced since the 1970s?
Clearly, the ecosystem responses to
actions such as decreased loadings of
contaminants are not simple. As an ex-
ample, "turning off the tap" of PCBs from
industrial discharges has not fully solved
the problems of PCBs in fish:
policymakers need to consider all
sources, including bottom sediments and
air, and need to consider the interactions
among these sources. They must also
recognize the response times involved
once the "taps are turned off.
Zebra Mussel; Great Lakes Filter
In 1986,,the zebra mussel arrived
unannounced, discharged from the
ballast water of a European ship. Its
introduction into the Great Lakes set in
"... the zebra mussel may
go far beyond that of a
nuisance. Some Great
Lakes researchers believe
that the zebra mussel has
the potential to funda-
mentally alter aquatic
community structures."
motion a series of cascading events. With
few natural predators, the imported
bivalve proliferated rapidly. Concern in
the early years coalesced around threats
to infrastructure, especially clogging of
water intake pipes, and the bottom
fouling of ships and boats. However,
recent studies indicate that impacts of the
zebra mussel may go far beyond that of a
nuisance. Some Great Lakes researchers
believe that the zebra mussel has the
potential to fundamentally alter aquatic
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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-I
>
H
n
O
t/i
-<
CO
-I
m
3
n
o
z
2
n
z
H
m
D
GROUNDWATER
O
Z
f/GURE 4. CONTAMINANT CYCLING IN THE GREAT LAKES ECOSYSTEM
-o
m
70
-------
community structures.
The half-inch long zebra mussel has a
voracious appetite. It feeds on plankton
and detritus that it filters from large
volumes of water. In so doing, it transfers
energy from the pelagic (open water)
system to the benthic (bottom-dwelling)
system, Zooplankton that otherwise
would be available for forage fish, instead
fuel a population explosion of zebra
mussels. Increased water clarity has been
observed across the basin as zooplankton
and detritus are removed by mussels
from the water column. In relatively
shallow areas, this improved clarity has
resulted in increased penetration of light
and increased growth of submerged
aquatic vegetation. This has likely in-
creased spawning, nursery and forage
areas for some fish species, while prob-
ably reducing them for others, Predaa'on
on fry can also increase due to increased
clarity. As noted in Chapter 4.1, in Lake
Erie, the impacts of zebra mussels on
detritus and zooplankton have resulted in
the severe impacts on native Unionidae
clams, and may be contributing to de-
clines in stocks of smelt, yellow and
white perch.
Impacts of the Changing Nutrient. Reg/me
The reduction in phosphorus loading
achieved over the last 25 years has
reduced the total quantity of algae in
Great Lakes waters enough to meet the
objectives set out in the GLWQA. This
reduction of phosphorus to historical
levels appears also to be having an
impact on the abundance of plankton in
the Great Lakes. Declines in levels of
zooplankton have been noted in Lakes
Ontario and Michigan. Zooplankton
sustain forage fish such as alewife and
smelt, which in turn sustain top predator
fish.
Levels of top predator fish in the
Great Lakes have been sustained at
unnaturally high levels through the en-
hanced productivity of the system (high
levels of phosphorus which supported
very large populations of forage fish) and
through stocking of indigenous and
exotic species such as chinook salmon
and rainbow trout. While this has contrib-
uted to the growth of an extensive sport
fishing industry, it is not sustainable in a
system in which nutrient levels are de-
clining. From an ecological (and ecosys-
tem management) point of view, expecta-
tions for fish yield (both commercial and
sport) need to be adjusted to levels that
are sustainable over the long term. This
has implications for targets for stocking
programs throughout the Basin, eco-
nomic implications (from reduced yield)
and poses potential conflicts with angler
groups. A related issue is the question of
what types of top predators should be
stocked. Species such as chinook salmon,
while they are desirable sport fish, are
not established as naturally-breeding
populations (except in some tributaries
in Lakes Ontario and Superior); lake
trout, one of the "natural" top predators
in the Great Lakes, are not so popular
with anglers.
A second set of scientific questions
arises from the question of the impact of
changing nutrient regime on community
structure. If lowered phosphorus loadings
are affecting community structure, are
they also having an effect on contami-
nant cycling? At this point; the answer is
not known.
STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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Restoring Aquatic Systems
A recent report. Great Lakes
Environmental Assessment (LTI, 1993),
outlines starkly the current conditions of
the Great Lakes fishery:
"Fish populations in the past were
comprised only of native species which
evolved together into a rich and diverse
population that was self-regulating,
productive, and comprised of many
species representative of oligotrophic
conditions. Fish communities in the Great
Lakes today are of smaller mean size,
composed principally of pelagic (open-
water) species, and large benthic and
predatory species that dominated early
fish communities are severely dimin-
ished. Communities are now dominated
by fecund (i.e. capable of rapid popula-
tion growth), non-indigenous (i.e. exotic)
species such as alewife and rainbow
smelt. Numerous native species are now
extinct or have been extirpated. Top
predators are also exotics (Pacific
salmon) or stocked hatchery-reared,
genetically inferior lake trout and the sea
lamprey...Current fish communities are
unstable, are difficult to manage, require
large amounts of public moneys to main-
tain some semblance of integrity, and are
constantly changing in response to the
various stresses that are imposed upon
them."
There are many lessons to be learned
from the past. One of these is that there
is no quick fix to the ecological problems
facing the fishery. Past management
decisions — stocking of non-indigenous
predators, alterations and destruction of
habitat — were made without consider-
ation of the impacts on the total aquatic
system. Ecological systems are complex
webs of interconnections, and. seemingly
innocent actions — building a dam here.
introducing a sport fish there — have
had profound and irreversible effects.
Actions to restore the Great Lakes fisher-
ies must proceed based on a firm under-
standing of the impacts of actions on
aquatic birds, mammals, amphibians and
reptiles, aquatic organisms at all trophic
levels, and people.
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5.0 MANAGEMENT CHALLENGES FOR THE FUTURE
As shown in Chapter 3, 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
other Lakes, though, progress has been
made in halting or undoing the damage
caused by past unsustainable practices:
water is cleaner, fish and wildlife
communities are
healthier than they
were twenty years ago,
some progress has
been made to protect
and enhance aquatic
habitat, and some
indigenous top
predators are
undergoing a
resurgence. Society is
moving — many may
argue, too slowly — to
embrace the principles
of sustainability, waste
reduction, pollution
prevention, and resource efficiency.
Despite the progress that has been made
in the last twenty years, much remains to
be done. 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 a massive scale. Exotic species
"The complexity of the
ecosystem and the intri-
cacy of interrelationships
pose tremendous chal-
lenges for managers in the
1990s. How well these,
and other challenges are
met will define the condi-
tion of the Great Lakes for
future generations."
continue to destabilize aquatic
communities, degrade habitat, and alter
cycling of nutrients and contaminants.
Individuals, municipalities, industries and
farms still discharge pollutants into air,
soil and water,
The complexity of the ecosystem and
the intricacy of interrelationships pose
tremendous challenges for managers in
the 1990s. How well these, and other
challenges are met will define the condi-
tion of the Great Lakes for future genera-
tions. Some of these challenges include:
The challenge of
adequate informa-
tion: This report (and
the Working Papers on
which it is based) cite
numerous examples of
areas in which basic
research and data
collection needs to be
done. Needs include
basic economic data
on the Great Lakes
Basin, data on quality
and quantity of aquatic
habitat, information on
contaminant cycling, a
better understanding of food web dynam-
ics, and spatial and temporal data on the
health of humans and aquatic biota.
Effective steps forward require good
information on which to base decision-
making, information on stresses, interac-
tions and effects. It is vital to fill these
priority data gaps.
The challenge of information man-
agement and communication: Informa-
tion on environmental conditions is
STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER
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possessed by hundreds of boards, agen-
cies, commissions, and interest groups in
the Basin. But all too often this informa-
tion is locked in filing cabinets, or sitting
on shelves. Moving forward to restore
ecosystem health will require taking
advantages of the tremendous strides
made in computer networks, integrated
information, cable, and other telecommu-
nication opportunities to improve com-
munication on environmental issues.
The challenge of how decisions are
made: Traditional decision-making is
linear. A decision is made by an indi-
vidual 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," interdis-
ciplinary, inter-jurisdictional and inter-
sectoral approaches to decision-making,
approaches which aim for consensus
among stakeholders.
The challenge of institutional ar-
rangements: The goal of restoring and
maintaining the integrity of the Great
Lakes Basin ecosystem poses many
challenges to institutional structures. It
requires recognition of ecosystem im-
pacts from all decisions: recognition of
effects beyond the narrow purposes of
specific laws, regulations or organiza-
tional missions. It also requires a consen-
sual "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 and coordination of actions
are key to implementing an ecosystem
approach to management.
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 needs of humans in a
balanced and sustainable manner.
The challenge of dealing with
biodiversity: Recognition of the need to
protect genetic resources and the habi-
tats needed to sustain various species,
genetic variety within populations, and
biological communities poses new chal-
lenges that fit well within the ecosystem
approach. Two of these 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.
The challenge of agreeing on end-
points 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 physi-
cal, chemical and biological integrity be
defined? What measurable conditions
should programs seek to attain?
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
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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 connecting deci-
sions 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 indica-
tors to measure success in restoring and
maintaining ecosystem integrity. Such
indicators can provide a focus for bring-
ing together seemingly disparate pro-
grams and serve as a basis for integrating
programs that were originally created to
deal with separate aspects of environ-
mental quality, resource management or
other purposes.
The challenge of subtle effects of
toxic substances on people and wild-
life: 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 sub-
stances have effects at such low concen-
trations that the ecosystem has virtually
no ability to absorb them, or the global
environment already contains concentra-
tions at levels that may be causing ad-
verse effects, how can use or generation
of them be avoided or prevented?
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APPENDIX A 400 YEARS OF CHANGE
Physical Characteristics
To understand the Laurentian Great Lakes
Basin ecosystem, one needs to
understand the scale and unique
characteristics of what the French
missionary, Father Gabriel Sagard,
dubbed the "Sweetwater Seas". The Great
Lakes — the world's largest freshwater
system — cover an area of 244,160 square
'kilometers [km] (94,278 square miles [m]).
More than 80,000 smaller lakes and some
750,000 km (466,041 m) of tributaries lie
within the Great Lakes Basin. It drains an
area of 765,990 square km (295,772
square m), an area bigger than the State
of Texas. Ontario and eight U.S. states lie
completely or partially within the Basin
(see Figure 1).
Because of their large surface area,
the Great Lakes are vulnerable to atmo-
spheric deposition of contaminants. In
other words, they are a "sink" for air-
borne pollutants, some of which are
transported from great distances outside
the Basin. Also, and importantly, the
Lakes are a source for some persistent
toxic contaminants such as PCBs that
volatilize from their surfaces (primarily
.during the summer months) into the air
and cycle through the system.
Not only are the Great Lakes large in
terms of surface area, they are also, (with
the exception of Lake Erie) very deep
(see Figure 1). These large, deep lakes
contain a huge volume of water, less than
1% of which leaves the system annually
through the bottleneck of the St.
Lawrence River. Because the flushing
time for the Lakes is so long — for ex-
ample, some 191 years for Lake Superior
— relatively small percentages of pollut-
ants entering the Lakes are exported
through their outflows. Contaminants can
also accumulate In bottom sediments and
in the food web.
History
In the year 1615, Samuel de Champlain
first sighted the Great Lakes. What he and
subsequent explorers discovered in the
Basin was a complex, balanced and
extremely diverse ecosystem. It was a
land in which many of the landforms had
been carved out or left behind in the
wake of the retreating Wisconsin
Glaciers. The retreating glaciers left
behind a legacy of lakeplains, moraines,
eskers, kettle lakes, inland wetlands, and
extensive rivermouth estuaries. A wide
variety of vegetation had adapted to the
diverse landforms and moderate climate.
In the cool, dry north, vast coniferous
forests clung to the thin, acidic soils of
the Boreal zone; in the wetter and
warmer south, Carolinian hardwood
forests grew on rich soils. Diverse wildlife
communities had adapted to the
vegetation and topography.
Population numbers remained low
until European settlement started in
earnest in the mid to late 1700s, The
history of European settlement is directly
linked to the area's principal geographic
feature — the Great Lakes and their
tributaries. In the absence of road net-
works, settlement of the Basin by Euro-
peans and transportation of goods was
dependent on transportation by water
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through lakes, rivers and linking canals.
Major "gateway" cities in the region such
as Montreal, Toronto, Buffalo, Cleveland,
Detroit, Chicago, Milwaukee and Duluth
all began as ports. Canal building was
started early to improve links within and
without the Basin; the Erie Canal link was
made in 1826. Commercial fishing in the
Lakes started in the early 1800s. The
major settlement period of the Great
Lakes coincided with, the rapid develop-
ment of industrial and transportation
technologies: with abundant water re-
sources, cheap hydroelectric power,
productive agricultural land, access to
raw materials and an available labor
force, the region developed an unparal-
leled advantage in domestic and overseas
markets. The presence of the Great Lakes
encouraged the development of water-
intensive industries and waterborne
shipment of raw material and finished
goods; later intensification saw the
emergence of a complex of primary and
secondary manufacturing.
Along with the economic growth
came rapid changes in the natural envi-
ronment. By the beginning of the 20*
century, settlers had cleared huge tracts
of forests in the Basin for agricultural
purposes or for timber, forcing many
species of wildlife to retreat. Dams built
on rivers to provide power for milling
grain and lumber were interfering with
fish spawning, and the removal of trees
and shrubs from streambanks was caus-
ing erosion and sedimentation. This also
led to changes in the temperature regime
of these rivers, contributing to the demise
of cold-water species. In coastal cities,
bulkheads and piers were built, nearshore
areas and coastal marshes filled, and
harbors and river mouths dredged. This
habitat destruction, coupled with over-
fishing, was causing a decrease.in fish
populations. Additional stress on aquatic
communities came later from exotic
species such as alewife and sea lamprey
that spread to Lake Erie and the Upper
Lakes through canals. To support rapidly
increasing populations, cities spread
outwards, and houses were built on
agricultural lands, forested areas, river
valleys, and wetlands. Residents were
dumping garbage and sewage into Lakes
and rivers or onto land, and industries
were discharging their wastes directly
into the air or water.
By the beginning of the 20th century,
there were many indications that water
quality was deteriorating and the Great
Lakes Basin ecosystem was out of bal-
ance. Public health concern over the
incidence of water-borne diseases such as
typhoid was such that in 1912 the Cana-
dian and U.S. governments referred the
issue of pollution of the Great Lakes to
the International Joint Commission (IJC)
for study. As a result of the Commission's
work, governments began building water
treatment and sewage treatment plants in
urban centers. This usually included
chlorinating the drinking water and
sewage effluent. In the 82 years since that
first referral, many Great Lakes environ-
mental problems have come to light —
problems including eutrophication, high
coliform bacteria levels in recreational
waters, impacts of persistent toxic con-
taminants on wildlife and fish, imbal-
ances in aquatic communities, loss of
habitat and many others. Governments ,
have tackled these issues as they arose.
Stocking programs were introduced
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in an attempt to re-establish native top
predator fish such as walleye and lake
trout. The walleye fishery in Lake Erie
has rebounded because of strict harvest
controls and a total fishing ban in the
early 1970s and also because of phospho-
rus controls. Walleye populations are
undergoing a resurgence in Lake Ontario
and have stabilized in Lakes Huron and
Superior. However, attempts to re-estab-
lish naturally-reproducing populations of
lake trout have not been successful ex-
cept in parts of Lakes Huron and Supe-
rior. Effective binational programs were
set up .to control populations of invading
lamprey. As new threats emerged from
such exotic species as zebra mussels,
quagga mussels, and purple loosestrife,
governments in the Great Lakes Basin
began to develop strategies to control
them.
The eutrophication of Lake Erie
grabbed headlines and attention in the
late 1960s and early 1970s and prompted
the U.S. and Canadian governments to
sign the Great Lakes Water Quality Agree-
ment of 1972. Under this agreement,
which focused on the eutrophication
problem, the governments developed
programs to reduce the loadings of phos-
phorus to the Lakes. As a result of joint
actions, phosphorus loadings to all the
Lakes have declined since 1976. Concen-
trations of phosphorus in open water
have also declined, which has resulted in
a noticeable reduction in the growth rate
of algae, both offshore and in nearshore
areas. Today, although eutrophication is
still a localized problem in some Areas of
Concern, it is no longer a problem in the
open waters of the Great Lakes.
In. 1978 the GLWQA was renegotiated
by the Parties and its scope was broad-
ened to include such issues as control of
persistent toxic substances, non-point
source pollution, and other matters. In
1987 the Agreement was expanded to
include contaminated sediments, air-
borne contaminants, management plans
and ecosystem indicators.
The Parties (and their provincial and
state partners) have used a mix of strate-
gies to tackle the problems of persistent
toxic substances. Basin-wide monitoring
and surveillance programs were devel-
oped to monitor contaminant levels in
air, water,, sediment, fish and wildlife.
Regulatory programs continue to reduce
discharges of pollutants. Demonstration
programs are showing the feasibility of
cleaning up contaminated sediments and
of restoring and protecting habitat. Pollu-
tion prevention is increasingly being
used to reduce use and discharge of
contaminants.
Increasingly, ecosystem-oriented
multimedia approaches are being devel-
oped. Under the GLWQA the Parties
agreed to prepare ecosystem-based
Remedial Action Plans in 43 Areas of
Concern in the Great Lakes to address
impaired uses. Under that agreement, the
Parties are also developing Lakewide
Management Plans to address lake-wide
contaminant problems, and are expand-
ing these to include other issues such as
habitat.
Strategies to deal with environmental
problems have changed in the last two
decades. In terms of pollution control,
governments are moving from a reliance
on "react and cure" approaches to those
that anticipate and prevent problems
from occurring. As part of this shift, the
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Parties agreed in 1990 to develop Pollu-
tion Prevention strategies for the Great
Lakes to assist municipalities, industries
and individuals reduce their loadings of
persistent toxic substances. With respect
to ecosystem impacts from physical and
biological stresses, governments have
been slower to respond. Habitat contin-
ues to be lost and exotic plant and animal
species are having profound effects on
the ecosystem, while most funds are
spent on the control and clean up of
persistent toxic substances,
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