STATE OF THE GREAT LAKES 2017
HIGHLIGHTS REPORT
An overview of the status and trends of the Great Lakes ecosystem
/n ii*i
Canada
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WHAT ARE THE
GREAT LAKES
INDICATORS
TELLING US?
CAN WE DRINK THE WATER?
YES The Great Lakes remain a source of high quality drinking water.
CAN WE SWIM AT THE BEACHES?
YES But some beaches are unsafe for swimming some of the time
due to bacterial contamination,
CAN WE EAT THE FISH?
YES But contaminants in fish require limits to be placed on the
amount of fish consumed in order to safeguard human health.
ARE THE LAKES FREE FROM POLLUTANTS AT LEVELS HARMFUL
TO HUMAN HEALTH AND THE ENVIRONMENT?
GENERALLY, YES But some pollutants in local areas, including in
designated Areas of Concern, remain at problem concentrations.
ARE THE LAKES SUPPORTING HEALTHY WETLANDS AND OTHER
HABITATS FOR NATIVE SPECIES?
IN SOME INSTANCES YES, AND IN OTHERS NO Results vary
significantly from location to location.
ARE THE LAKES FREE FROM EXCESS NUTRIENTS?
NO Nutrient loadings in Lake Erie and some nearshore areas of
Lakes Huron, Michigan and Ontario are causing severe impacts
due to the formation of toxic and nuisance algae.
ARE WE WINNING THE BATTLE AGAINST AQUATIC INVASIVE SPECIES?
NO While the introduction of new non-native species has declined,
the spread and impacts of aquatic invasive species already in the
lakes continues.
IS GROUNDWATER NEGATIVELY AFFECTING THE WATER QUALITY
OF THE LAKES?
GENERALLY, NO But some localized areas of contamination exist.
ARE LAND USE CHANGES IMPACTING THE LAKES?
YES Growth, development, and land-use activities stress the waters
of the Great Lakes.
OVERALL,
THE GREAT LAKES
ARE ASSESSED
AS FAIR AND
UNCHANGING.
While progress to
restore and protect
the Great Lakes has
been made, including
the reduction of toxic
chemicals, we are still
facing challenges with
issues such as invasive
species and nutrients.
In addition, the
ecosystem is large
and complex and
it can take years to
respond to restoration
activities and policy
changes.
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STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Why are the Great Lakes Important?
The Great Lakes contain one fifth of the world's fresh
surface water supply and are one of the most ecologically
diverse ecosystems on earth. They provide drinking
water to tens of millions of Canadians and Americans
and are important to the economies of both Canada
and the United States, supporting manufacturing,
transportation, farming, tourism, recreation, clean
energy production, and other forms of economic growth.
How are Governments Working
Together to Protect the Great Lakes?
2017 marks the 45th anniversary of the signing of
the Great Lakes Water Quality Agreement by the
Governments of Canada and the United States.
The Agreement commits both countries to working
cooperatively to restore and protect the water quality and
aquatic ecosystem health of the Great Lakes. Through the
Agreement, the Governments of Canada and the United
States engage the provincial and state governments of
Ontario, Illinois, Indiana, Michigan, Minnesota, New York,
Ohio, Pennsylvania, and Wisconsin, Tribes, First Nations,
Metis, municipal governments, watershed management
agencies, other local public agencies, industry and the
public in actions to ensure that the Great Lakes remain
an important and vibrant natural resource for the benefit
and enjoyment of this generation and those to come.
How is the Health of the Great Lakes
Assessed?
The Governments of Canada and the United States,
together with their many partners in protecting the
Great Lakes, have agreed on a set of 9 indicators
of ecosystem health. These indicators are in turn
supported by 44 sub-indicators, measuring such
things as concentrations of contaminants in water
and fish tissue, changes in the quality and abundance
of wetland habitat, and the introduction and spread
of invasive species. To create this report, more than
180 government and non-government Great Lakes
scientists and other experts worked to assemble
available data to populate the suite of sub-indicators
and to agree on what the indicators are telling us. Each
indicator was assessed in relation to both status and
trend. Status is defined as Poor, Fair or Good. Trend
is defined as Deteriorating, Unchanging or Improving.
How is the Assessment of the Great
Lakes Used?
Assessments of the Great Lakes help Governments to
identify current, new and emerging challenges to Great
Lakes water quality and ecosystem health. Assessments
also help Governments to evaluate the effectiveness of
programs and policies in place to address challenges,
and help inform and engage others. We all have a role
to play in helping to restore and protect the Great Lakes.
Overall Assessments of the Nine Great
Lakes Indicators of Ecosystem Health
Great Lakes Indicator
Status and Trend
Drinking Water
Status: Good
Trend: Unchanging
Beaches
Status: Fair to Good
Trend: Unchanging
Fish Consumption
Status: Fair
Trend: Unchanging
Toxic Chemicals
Status: Fair
Trend: Unchanging to Improving
Habitats and Species
Status: Fair
Trend: Unchanging
Nutrients and Algae
Status: Fair
Trend: Unchanging to Deteriorating
Invasive Species
Status: Poor
Trend: Deteriorating
Groundwater Quality
Status: Fair
Trend: Undetermined
Watershed Impacts
and Climate Trends
Watershed Impacts:
Status: Fair
Trend: Unchanging
Climate Trends:
No Overall Assessment
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Drinking Water
Status: Good Trend: Unchanging
Nearly 30 million Americans and the
majority of the 11 million Canadians living
in the basin get their drinking water from
the Great Lakes.
The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should be a source of safe, high-
quality drinking water"
Percentage of Canadian Drinking Water Tests
Meeting Standards
Assessment Highlights
The Drinking Water indicator shows that the status of treated
drinking water in both Canada and the U.S. is Good and the
trend is Unchanging since the last report in 2011. This shows
that the Great Lakes continue to be a high-quality source of
drinking water; however, as with all source waters, water
from the Great Lakes must be treated to make it safe to
drink.
Ontario and U.S. state agencies have different ways of
analyzing and reporting on the quality of treated drinking
water, however, both compare microbial, radiological and
chemical parameters in treated drinking water to health-
based standards. In the Province of Ontario, almost 60%
of the population gets their drinking water from the Great
Lakes and treated water tests met Ontario Drinking Water
Quality Standards 99.83% - 99.88% of the time from 2007
to 2014. In the U.S., 95 - 97% of the U.S. population living
within the Great Lakes Basin, or approximately 27 million
people, were serviced with drinking water that met all
applicable health-based drinking water quality standards
from 2012 to 2014.
s g
f C
I I I I I I I
2008-09 2009-10 2010-11 2011-12 2012-13 2013-14
Sub-Indicators Supporting the Indicator Assessment
Sub-Indicator
Lake Superior Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Treated Drinking Water
No lake was assessed separately
Great Lakes Basin assessment is Good and Unchanging
Status:
GOOD
FAIR
UNDETERMINED
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STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Great Lakes beaches are enjoyed by millions of
residents and tourists each year and contribute
significantly to local economies; however, some
beaches are closed at times due to bacterial
contamination caused by overflow of sewage
treatment systems, stormwater runoff and other
sources.
The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should allow for swimming and
other recreational use, unrestricted by environmental quality concerns"
Assessment Highlights
The overall status of Beaches is Fair to Good and the trend
is Unchanging since 2011. The Beaches indicator shows
that many monitored beaches in the Great Lakes are safe
for swimming and recreational use throughout most of
the swimming season.
The U.S. and Canada use different bacterial standards
or criteria to determine when a beach is unsafe for
swimming or other recreational activities. The Ontario
standards are more stringent and therefore Ontario often
has more beach health advisories issued. Approximately
1,000 beaches along the Great Lakes shoreline are
monitored for the fecal bacteria indicator E. coli each year.
Over the 2011 to 2014 time period, the percentage of
days that monitored Canadian Great Lakes beaches met
Ontario bacterial standards for swimming averaged 78%.
The U.S. Great Lakes beaches monitored during this same
time period were open and safe for swimming 96% of the
time on average. However, the status of Lake Erie beaches
in Canada and the U.S. has deteriorated from the previous
2008 to 2010 reporting period. Sources of E. coli for all of
the Great Lakes can include wastewater treatment plants,
runoff from the land after a heavy rainfall, improperly
working septic systems, and even large flocks of gulls.
U.S. Great Lakes Beaches: Percent of
Season Open By Lake
100%.
90%.
80%.
70%.
60%.
50%.
40%-
30%.
20%.
10%.
II
Lake Michigan I Lake Huron I
~ 100% ¦ 80% - <100% ~ 50% - <80% |
11 b11±| k| e
Lake Ontario
Sub-Indicators Supporting the Indicator Assessment
Sub-indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Beach Advisories
Unchanging
Unchanging
Unchanging
Deteriorating
Unchanging
Status:
GOOD
FAIR
POOR
UNDETERMINED
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Fish Consumption
Status: Fair Trend: Unchanging
The Great Lakes support commercial,
recreational and subsistence fisheries;
however; some chemicals present in the
Great Lakes, including PCBs, mercury and
dioxins, accumulate in fish tissues and
may reach concentrations which could
harm human health.
The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should allow for human
consumption offish and wildlife unrestricted by concerns due to harmful pollutants"
Assessment Highlights
The Fish Consumption indicator reveals that in all the
Great Lakes contaminants in edible portions offish have
declined over time. However, in Lakes Erie and Huron, recent
concentrations of PCBs and mercury are stable or slightly
increasing. The status of contaminants in edible portions of
fish is assessed as Fair and the trend is Unchanging since last
reported in 2011.
species will likely continue to complicate the cycling of
contaminants in the Great Lakes and may impact the levels
of contaminants in fish.
PCBs in Edible Fish Tissue Have Declined
But Are Still Above Guidelines
Contaminants causing consumption restrictions of Great
Lakes fish typically include PCBs, mercury, and dioxins.
PCBs drive the majority of fish consumption advice in
both the U.S. and Canada. PCB levels in edible portions
offish tissue have decreased by 90% in some cases, but
are still above consumption benchmarks. Mercury ievels
have generally declined over the last four decades and,
depending on the fish species and lake, are lower than most
fish consumption advisory benchmarks. However, in Lakes
Erie and Huron, PCBs and mercury have remained stable
or are slightly increasing. Non-legacy contaminants, such
as Perfluorooctanesulfonic acid or PFOS (a stain repellent),
continue to be a monitoring priority and will be included
in future State of the Great Lakes reporting as necessary.
Additional stressors such as warming waters and invasive
Sub-Indicators Supporting the Indicator Assessment
Sub-indicator
Lake Superior Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Contaminants in Edible Fish
Unchanging Improving
Unchanging
Deteriorating
Improving
Status:
GOOD
FAIR
POOR
UNDETERMINED
Lake Ontario
Lake Michigan
Lake Huron
Lake Superior
Lake Erie
Represents an estimated binational
health related benchmark for the
general population
1985
1995
Year
2005 2015
7000
6000
5000
o 4000
c (ti 3000
qj —I
O 2000
1000
0
1975
5
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should be free from pollutants in
quantities or concentrations that could be harmful to human health, wildlife, or aquatic organisms, through direct exposure
or indirect exposure through the food chain"
Some toxic chemicals in the Great Lakes have
declined substantially over the past 40 years. While
significant progress has been made, the Great Lakes
are still experiencing concentrations of some toxic
chemicals, such as PCBs, that pose a threat to human
health and the environment.
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Toxic Chemicals
Assessment Highlights
The Toxic Chemicals indicator shows that nearly all older
and regulated or banned chemicals, generally referred to as
legacy contaminants and include Polychiorinated Biphenyls
(PCBs) and mercury, have decreased over the past 40 years,
in general, non -legacy compounds, such as Polybrominated
Diphenylethers (PBDEs), have shown slow declines in recent
years, although some replacements for these compounds
are increasing in the environment. Overall, the status of Toxic
Chemicals is Fair and the trend is Unchanging to Improving.
In the offshore waters of the Great Lakes, the iong-term
trends for many contaminants, such as PCBs and PBDEs,
show declines to lower levels and little or no change in the
more recent trend, although concentrations are higher in the
lower lakes. There are however, occasional exceedances of
water quality objectives and criteria for PCBs.
Contaminant levels in Great Lakes whole fish and Herring
Gull eggs have decreased significantly since the 1970s.
Although declines are being seen, concentrations of
some compounds, like PCBs and PBDEs, may still exceed
environmental quality guidelines or objectives. Localized
areas of highly contaminated sediment in Areas of Concern
(AOCs) and hazardous waste sites may continue to act
as sources of these and other contaminants to the lakes.
Residual sources of PCBs remain in the Great Lakes Basin
and throughout the worid. PCBs and other chemicals can
be carried by air currents from within and outside the basin
to the Great Lakes; therefore, atmospheric deposition will
remain a significant source of PCBs and other contaminants
for decades into the future.
The Toxic Chemicals indicator includes data from several
long-term monitoring programs. These programs have been
tracking a wide variety of chemicals including mercury,
PCBs and PBDEs in the environment for years, and in some
cases, decades. The number of substances being monitored
is increasing and evolving, thereby improving our base of
knowledge to lead to more robust assessments; including
chemicals such as current-use pesticides, pharmaceuticals
and personal care products.
Refer to the State of the Great Lakes 2017 Technical Report
for chemicals monitored in the Great Lakes.
PCBs in Whole Fish are Decreasing
PCBs in Air are Decreasing
PBDEs are Higher in
Lakes Erie and Ontario
120
0 Environment and Climate Change Can a
• U.S. Environmental Protection Agency
GLWQA Guideline (1987)
-C 100
Point Pet re,
Lake Ontario
80
60
m
40
Eagle Harbor,
Lake Superior
20
1975 1900 1985 1990 1995 2000 2005 2010 2015
1985 1990 1995 2000 2005 2010 2015 2020
Year
Year
Sub-Indicators Supporting the Indicator Assessment
Sub-Indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Toxic Chemical Concentrations
Improving
Unchanging
Unchanging
Unchanging
Unchanging
Toxic Chemicals in Sediments
Unchanging
Unchanging
Unchanging
Improving
Improving
Toxic Chemicals in Great Lakes Whole
Fish
Unchanging
Improving
Unchanging
Unchanging
Improving
Toxic Chemicals in Great Lakes
Herring Gull Eggs
Improving
Improving
Improving
Unchanging
Unchanging
Atmospheric Deposition of Toxic
Chemicals
No lake was assessed separately
Great Lakes Basin assessment is Fair and Improving
Status:
GOOD
FAIR
POOR
UNDETERMINED
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Habitat and Species
Status: Fair Trend: Unchanging
The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should support healthy and
productive wetlands and other habitats to sustain resilient populations of native species"
The Great Lakes are one of the richest and
most ecologically diverse ecosystems on
Earth and include vital coastai wetlands
that cleanse impurities from water,
regulate water flows and provide habitat
for many species. However, urban and
agricultural development, pollution,
invasive species, and other factors
threaten the health of Great Lakes species
and their habitats.
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Habitat and Species
Sub-Indicators Supporting the Indicator Assessment
Sub-Indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Coastal Wetland Amphibians
Unchanging
Unchanging
Unchanging
Unchanging
Unchanging
Coastal Wetland Birds
Unchanging
Unchanging
Unchanging
Deteriorating
Improving
Coastal Wetland Fish
Coastal Wetland Plants
Coastal Wetland Invertebrates
No lake was assessed separately
Great Lakes Basin assessment is Fair and Improving
No lake was assessed separately
Great Lakes Basin assessment is Fair and Deteriorating
Undetermined Undetermined Deteriorating Deteriorating Unchanging
Coastal Wetlands: Extent and
Composition
Aquatic Habitat Connectivity
No lake was assessed separately
Great Lakes Basin assessment is Undetermined
Improving
Improving
Improving
Improving
Improving
also been seen in the diversity of coastal wetland fish species
with recent data showing an average of 10 to 13 species
per coastal wetland, with some wetlands having as many
as 28. Although many invertebrates, birds and plants have
experienced long-term declines, some birds and amphibians
are showing a more recent unchanging trend. These stable
populations may be preliminary indications of some progress
in the rehabilitation and restoration of coastal wetlands.
Assessment Highlights
The Habitat and Species indicator is used to assess habitats,
such as wetlands, along with the species that reside in these
areas. The Habitat and Species indicator shows that across
the basin, the status is quite variable, ranging from good to
poor and improving to deteriorating, depending on the lake
basin and habitat or species of interest. The health of various
species in the Great Lakes is also reflective of the availability
and condition of the habitat that they dwell in and need.
Overall, the Habitat and Species indicator is assessed as Fair
and Unchanging.
Coastal Wetlands
Despite the fact that coastal wetland restoration and
protection efforts have improved specific areas, wetlands
continue to be lost and degraded. Efforts to better
track and determine the extent and rate of this loss are
currently underway. In the southern lakes region, almost
all coastal wetlands are degraded by nutrient enrichment,
sedimentation, or a combination of both. In Lake Ontario,
water-level regulation also limits natural variation in
wetlands, though work is underway to address this situation.
A more recent concern in the southern lakes region and Lake
Huron is the expansion of the invasive Frog-bit, a floating
plant that forms dense mats capable of eliminating native
submergent plants in coastal wetlands. Of similar concern,
the invasive Water Chestnut is expanding rapidly in Lake
Ontario.
Coastal wetland habitats in some regions of the Great Lakes,
in particular in the northern parts, are intact and show fewer
signs of impairment. Across the basin, improvements have
Status:
GOOD
FAIR
POOR
UNDETERMINED
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STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Habitat and Species
Aquatic Food Web
The Great Lakes aquatic food web is made of many
important species, ranging from tiny plants and animals
(phytoplankton and zooplankton) to top predator fish.
Zooplankton communities in all lakes except Lake Huron
are generally in good condition, although changes in
quantity, density and type are occurring in Lakes Michigan
and Ontario. Changes that are occurring in zooplankton
communities are consistent with decreasing nutrient
concentrations in offshore waters. Low nutrients levels
result in a loss of algae for zooplankton to feed on. Also,
Diporeia, a small bottom-dwelling shrimp-like species and
an important source of food for fish, has severely declined
in all the lakes except Lake Superior. The invasive dreissenid
mussels (specifically Zebra and Quagga Mussels) have
likely compounded this problem. Dreissenid mussels graze
on phytoplankton and small zooplankton as well as filter
and store nutrients which can prevent the movement of
nutrients into the open waters of the lake. The situation is
complex and the exact mechanisms causing these changes in
Diporeia and zooplankton have yet to be fully determined.
Zooplankton and phytoplankton communities are the main
source of food for prey fish and are essential to sustaining
a healthy food web. Prey fish communities across the
Great Lakes continue to change, although the direction and
magnitude of those changes vary. The prey fish community
is considered fair overall based on the diversity and the
proportion of native prey fish species in the Great Lakes
despite fluctuations in population levels. The abundance of
prey fish is influenced by food availability and the abundance
of predator fish, such as Lake Trout and Walleye, which eat
prey fish to survive. A balance between the numbers of
top predator fish and the available prey fish in the lakes is
important.
The status of populations of native predator fish, such as
Walleye and Lake Trout, is variable; however, populations
of these fish are improving in some cases. Lake Trout
populations, for example, are improving in some areas of the
Great Lakes with support from stocking and rehabilitation
efforts. In fact, natural reproducing populations of Lake Trout
are now routinely detected in southwestern Lake Michigan,
and wild Lake Trout make up over 50% of the population
in Lake Huron. While changes in Lake Sturgeon status will
take a long time to manifest, activities such as habitat
improvements, dam removals, and stocking efforts indicate
an improving trend for this species.
Diporeia Art Declining - Quagga Mussels are Increasing
Diporeia Populations
2000 2003 2007 2012
> j| TTf T-
Quagga Mussel Populations
2000 2003 2007 2012
Sub-Indicators Supporting the Indicator Assessment
Sub-Indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Phytoplankton
Unchanging
Deteriorating
Deteriorating
Deteriorating
Unchanging
Zooplankton
Unchanging
Unchanging
Unchanging
Unchanging
Unchanging
Benthos
Unchanging
Unchanging
Unchanging
Deteriorating
Unchanging
Diporeia
Unchanging
Deteriorating
Deteriorating
Deteriorating
Deteriorating
Prey fish
Unchanging
Deteriorating
Undetermined
Improving
Deteriorating
Lake Sturgeon
Improving
Improving
Improving
Improving
Improving
Walleye
Unchanging
Unchanging
Unchanging
Improving
Unchanging
Lake Trout
Unchanging
Improving
Improving
Improving
Improving
Fish Eating and Colonial Nesting
Waterbirds
Unchanging
Unchanging
Unchanging
Unchanging
Unchanging
Status: GOOD FAIR
UNDETERMINED
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Nutrients and Algae
Status: Fair Trend: Unchanging to Deteriorating
The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should be free from nutrients
that directly or indirectly enter the water as a result of human activityj in amounts that promote growth of algae and
cyanobacteria that interfere with aquatic ecosystem health, or human use of the ecosystem"
Algae occur naturally in freshwater systems and are essential to
a healthy aquatic food web. Phosphorus is a key nutrient for the
growth of aquatic plants. However, too much phosphorus can
lead to too much algae in the water, which can be harmful to the
environment, the economy and human health. Excessive nutrient
loadings to Lake Erie, some nearshore areas, and embayments of
the Great Lakes contribute to harmful and nuisance algal blooms.
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Nutrients and Algae
Assessment Highlights
The 1972 GLWQA focused on phosphorus reductions. In the
1980s and early 1990s, basin-wide restoration efforts were
successful in reducing nutrient-related runoff and conditions
in the lakes improved. These efforts included the regulation
of phosphorus concentrations in detergents, investments
in sewage treatment, and the implementation of best
management practices on agriculture lands and in expanding
urban areas. Despite these efforts, there is a nutrient
imbalance in the Great Lakes. With the recent resurgence of
the nearshore algal problem in some areas and with other
changes in the ecosystem, the problem has become more
complicated. Overall, the conditions result in a status of Fair
and a trend of Unchanging to Deteriorating for this indicator.
Many offshore regions of some of the Great Lakes have
nutrient levels below desired concentrations. In fact,
concentrations may be too low in some areas, resulting
in insufficient growth of key phytoplankton species which
form the base of the food chain. Only in Lake Superior are
offshore phosphorus concentrations considered in acceptable
condition. Conversely, there are excess nutrients in many
nearshore areas. While a certain level of nutrients is good,
too much may lead to the development of nuisance and
harmful algal blooms (HABs) and hypoxic zones (areas with
low oxygen levels). This issue is primarily a concern in Lake
Erie, parts of Lake Ontario, Saginaw Bay and Green Bay, along
with other nearshore areas that experience elevated nutrient
levels. Algal blooms can be harmful to both ecosystem and
human health. The western basin of Lake Erie and some
parts of Lake Ontario have experienced a resurgence of HABs
since 2008, adversely impacting ecosystem health as well as
commercial fishing, municipal drinking water systems and
recreational activities. Algal blooms are particularly harmful
when they are dominated by cyanobacteria (or "blue-
green" algae) which can produce toxins such as microcystin.
These toxins can impact drinking water safety or can cause
gastrointestinal upsets, skin rashes and at elevated levels can
be fatal to many organisms.
Total Phosphorus Concentrations in the Great Lakes
Total Phosphorus (mg/L)
Spring 2013 (Lakes Onfarioand Superic
Spring 2014 (Lakes Erie, Michigan, Huron and Ge
Cladophora is a nuisance algae that is broadly distributed
over large areas of the nearshore regions of Lakes Erie,
Ontario, Huron and Michigan. Large mats of Cladophora
give the impression that nutrient concentrations are high
in the nearshore. However, in some areas, these mats of
nuisance algae persist despite low nutrient concentrations
in the surrounding water, which is why the management
of Cladophora has become such a challenge. Excessive
Cladophora poses many problems including beach and
shoreline fouling, clogging of municipal water intakes and
unpleasant aesthetics, as well as tourism and recreational
fishing impacts. There are also significant ecological impacts
of excessive Cladophora growth and, when washed up on the
shoreline, Cladophora may harbour pathogens and create
an environment conducive to the development of botulism
outbreaks which pose a risk for fish and wildlife.
Warmer temperatures, higher frequency and intensity of
precipitation events, and invasive species, in particular Zebra
and Quagga Mussels, are confounding factors in the cycling
and uptake of nutrients in the lakes. These factors may lead
to increased frequency, distribution and severity of HABs,
hypoxic zones and Cladophora.
Sub-Indicators Supporting the Indicator Assessment
Sub-Indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Nutrients in Lakes
Unchanging
Deteriorating
Deteriorating
Deteriorating
Deteriorating
Cladophora
Unchanging
Undetermined
Undetermined
Undetermined
Undetermined
Harmful Algal Blooms
Undetermined
Undetermined
Undetermined
Deteriorating
Deteriorating
Water Quality in Tributaries
Unchanging
Undetermined
Unchanging
Unchanging
Unchanging
Status:
GOOD
FAIR
POOR
UNDETERMINED
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Invasive Species
Status: Poor Trend: Deteriorating
The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should be free from the
introduction and spread of aquatic invasive species and free from the introduction and spread of terrestrial invasive species
that adversely impact the quality of the Waters of the Great Lakes"
The number of new invasive species entering
the Great Lakes has been significantly reduced;
however, those invasive species already in the
Great Lakes such as Sea Lamprey, Zebra Mussels
and Purple Loosestrife continue to cause more than
$100 million annually in economic impacts in the
U.S. alone.
13 STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Invasive Species
Assessment Highlights
The Invasive Species indicator highlights that the spread and
impact of aquatic and terrestrial invasive species continues to
be a significant stress to biodiversity in the Great Lakes region.
As such, the Invasive Species indicator is assessed as Poor and
the trend is Deteriorating.
To date, over 180 aquatic non-native species have become
established in the Great Lakes Basin. Only one new non-
native species has been discovered since 2006, a zooplankton
called Thermocyclops crassus. This tremendous success
in reducing the introduction of invasive species is largely
due to the regulation of ballast water from trans-oceanic
ships. Additionally, the Asian carp species established in the
Mississippi River, which are threatening the Great Lakes, have
not become established. This success is attributed to the
important prevention efforts in both countries, including the
U.S. Army Corps of Engineers electrical barrier on the Chicago
Sanitary and Ship Canal.
Despite the significant slowdown in recent introductions, the
impacts of established invaders persist and their ranges within
the lakes are expanding. It is believed that at least 30% of
the aquatic non-native species found in the Great Lakes have
significant environmental impact.
For several decades, Sea Lamprey have been causing severe
ecological impacts. However, Sea Lamprey abundance has
been reduced significantly in the five lakes through active, on-
going, and basin-wide control measures. But, native fish such
as Lake Trout, Walleye and Lake Sturgeon are still subject to
Sea Lamprey predation. Sea Lamprey remain an impediment
to achieving critical fish community and ecosystem objectives
and therefore continuation of and improvements to Sea
Lamprey control are required.
Dreissenid mussels, also known as Zebra and Quagga Mussels,
are prominent invasive species in the Great Lakes as well. In
many offshore regions, Zebra Mussels have been displaced
Sub-Indicators Supporting the Indicator Assessment
Sub-Indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Impacts of Aquatic Invasive Species
Deteriorating
Deteriorating
Deteriorating
Deteriorating
Deteriorating
Dreissenid Mussels
Unchanging
Deteriorating
Deteriorating
Improving
Deteriorating
Sea Lamprey
Improving
Improving
Improving
Improving
Unchanging
Terrestrial Invasive Species
Deteriorating
Deteriorating
Deteriorating
Deteriorating
Deteriorating
Status:
GOOD
FAIR
POOR
UNDETERMINED
Aquatic Invasive Species -
Establishments Have Slowed Down
¦ Live Wells/Recreational Boating
¦ Bait Release
¦ Escaped Culture
¦ Hitchhiker with Organisms in Trade
¦ Aquarium
¦ Canals
¦ Plant ed/Stocked
¦ Unknown
¦ Shipping
1839 1864 1889 1914 1939 1964 1989 2014
Year
by increasing populations of Quagga Mussels. While in some
nearshore regions, populations of both species seem to
be stable or declining. Overall, dreissenids are a dominant
component of the bottom-dwelling community. Consequently,
they have played an instrumental role in the alteration of
the zooplankton and phytoplankton communities as well as
disrupting the nutrient cycle and increasing water clarity.
On the land, terrestrial invasive species have a significant
impact and continue to spread throughout the Great
Lakes Basin. Five terrestrial invasive species were assessed
collectively—Phragmites, Purple Loosestrife, Garlic Mustard,
Emerald Ash Borer and Asian Long-horned Beetle. These
species are widely distributed and their ranges appear to be
expanding. All five of these species have a detrimental impact
on the surrounding ecosystem, including degrading habitat
and water quality.
Limiting the impact of existing invaders is critical. However,
binational prevention efforts, including continuing early
detection and rapid response programs, are where the biggest
difference can be made to ensure the Great Lakes are healthy,
safe and sustainable.
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
14
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Groundwater
Status: Fair Trend: Undetermined
Groundwater can enhance surface water
quality and quantity and provide essential
aquatic habitats. Groundwater can also
transmit contaminants and excessive
loads of nutrients to the Great Lakes.
The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should be free from the harmful
impact of contaminated groundwater "
Assessment Highlights
The Groundwater Quality indicator is assessed as Fair
but the trend is Undetermined due to insufficient long-
term data. The concentrations of nitrate, primarily
from agricultural practices, and chloride, mainly from
the urban use of de-icing salt, are being used to assess
groundwater quality. Elevated concentrations of both of
these constituents in water can have detrimental impacts
to ecosystem and human health.
Portions of the Great Lakes Basin with more intense
development, such as areas within the basins of Lakes
Michigan, Erie and Ontario, are generally assessed as
fair. Groundwater quality is generally assessed as good
in the less developed areas, such as portions of the Lake
Huron basin. A better understanding about the impacts
of contaminated groundwater and its interaction with the
waters of the Great Lakes is needed, particularly for the
nearshore zone.
Groundwater Quality Assessment by Lake Basin
Quality Status
Sub-Indicators Supporting the Indicator Assessment
Sub-indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Groundwater Quality
Undetermined
Undetermined
Undetermined
Undetermined
Undetermined
Status:
GOOD
FAIR
POOR
UNDETERMINED
15
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Watershed Impacts and
Climate Trends
Status: Fair Trend: Unchanging
The 2012 Great Lakes Water Quality Agreement states that "the Waters of the Great Lakes should be free from other
substances, materials or conditions that may negatively impact the chemical, physical or biological integrity of the Waters of
the Great Lakes"
Between 1971 and 2011 the number of
people living in the Great Lakes Basin
increased by almost 20 percent, resulting
in significant changes to land use in many
Great Lakes watersheds. Shifting climate
trends are also being experienced across
the Great Lakes Basin, including warming
temperatures, changing precipitation
patterns, decreased ice coverage, and
more extreme fluctuations of water levels.
Changes in land use and shifting climate
trends can have a profound effect on Great
Lakes water quality.
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
16
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Watershed Impacts and Climate Trends
Assessment Highlights
Overall, the Watershed Impacts and Climate Trends indicator
is assessed as Fair and Unchanging. This indicator includes
ail "other substances, materials or conditions" that are not
highlighted in the eight other indicators noted on page 2,
but are important with respect to the state of the Great
Lakes. The indicator currently includes an array of land-based
conditions which can affect water quality as well as climate
trends which can impact all parts of the ecosystem.
Watershed Impacts
Population, development, agriculture and road density can
cause land-based pressures on the Great Lakes ecosystem,
especially in areas with larger population centres. Although
urban and agricultural lands are important to the Great Lakes
region because they help support people and the economy,
the water quality in these areas, in particular the lower
lake basins, is more susceptible to impairments or threats.
Conversely, the northern part of the Great Lakes Basin has
lower relative amount of stress since it remains largely
undeveloped and is dominated by natural cover.
Agricultural Lands in the Southern
Parts of the Great Lakes Basin
Across the entire basin, almost 400 square kilometres (154
square miles) or 40,000 hectares of natural lands were
converted to developed land cover between 2001 and 2011.
The latest analysis shows a growing trend of increasing
development, resulting in a ioss of agricultural, forested and
natural lands.
Research has shown that an increase in forest cover
improves water quality. In particular, forest cover within a
riparian zone (i.e. land along a lake, river or stream), plays a
key role in stabilizing soil and can help reduce the amount of
runoff from the land and reduce nutrient loadings and other
non-point source pollutants. Forest cover in the riparian
zones varies with the Lake Superior watershed having the
highest amount at 96% and the Lake Erie watershed having
the least with 31%. With half of the Great Lakes Basin
currently in agricultural or developed land use, and with
much less forest cover in the more southern parts of the
Great Lakes Basin, it is evident that land-based pressures can
significantly impact water quality.
Forest Cover Helps to Improve Water Quality
Sub-Indicators Supporting the Indicator Assessment
Sub-Indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Forest Cover
Unchanging
Unchanging
Unchanging
Improving
Deteriorating
Land Cover
Unchanging
Unchanging
Unchanging
Unchanging
Unchanging
Watershed Stressors
Unchanging
Unchanging
Unchanging
Unchanging
Unchanging
Hardened Shorelines
Undetermined
Undetermined
Undetermined
Undetermined
Deteriorating
Tributary Flashiness
No lake was assessed separately
Great Lakes Basin trend is Unchanging
Human Population
Decreasing
Increasing
Increasing
Increasing
Increasing
Status:
GOOD
FAIR
POOR
UNDETERMINED
kilometres
Riparian Forest Rating
Poor
i Fair
Good
17
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Watershed Impacts and Climate Trends
Climate Trends
Data collected over the past 30-40 years in the Great
Lakes Basin show increases in the amount of precipitation,
increases in summer surface water temperature and a
reduction in ice cover. Lake levels have also generally
decreased, although there has been a recent rebound in
water levels in the past few years. It is not yet possible to say
with any certainty, however, if changes in water levels are
due to human activity or natural long-term cycles.
These changes can affect the health of the Great Lakes Basin
including impacts to spawning and other habitats for fish
species, the amount and quality of coastal wetlands and
changes in forest composition. Shifts in climate trends can
also lead to the northward migration of invasive species and
alter habitat in a way that favours some invaders over native
species. An extended growing season, increases in runoff and
nutrient loads and changes to contaminant cycling could also
result from a shift in climate trends.
Assessing Climate Trends
Climate information is not assessed in the same
manner as other indicators in this report. For example,
the ecosystem has adapted to and needs both high
and low water levels and neither condition can be
assessed as Good or Poor. However, prolonged
periods of high or low water levels may cause stress
to the ecosystem. Therefore, climate trends are simply
assessed as Increasing, Unchanging or Decreasing
over a defined period of time.
Sub-Indicators Supporting the Indicator Assessment
Sub-Indicator
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Precipitation Amounts
(1948-2015)
No lake was assessed separately
Great Lakes Basin trend is
Surface Water Temperature
(1979/1980-2014)
~
Undetermined
Undetermined
Ice Cover
(1973-2015)
*
*
*
*
*
Water Levels
(1985-2015)
*
*
*
*
No significant
change
Baseflow Due to Groundwater
No lake was assessed separately
Great Lakes Basin trend is Undetermined
Surface Water Temperatures are Increasing
O
o
Surface Water Temperature
data from 3 locations in Lake Superior
-------
Lake-by-Lake Snap Shot
GOOD
POOR
Lake Superior's ecosystem is in good condition and the
trend is unchanging. Fisheries in the open waters are
in good condition, supported by a robust lower food
web including srnail, shrimp-like species Diporeia and
Mysis. There are self-sustaining populations of Lake
Trout and increasing abundance of Lake Sturgeon. Most
major habitats are in good condition on a lakewide scale,
including coastal wetlands. Concentrations of iegacy
contaminants in the environment, such as PCBs, are
generally decreasing or remaining stable. However, fish
consumption advisories continue to be in effect due to
pollutants such as mercury and PCBs. Aquatic invasive
species, in particular Sea Lamprey, are still causing harm.
In addition, warming waters are stressing some cold-water
species, such as Brook Trout. Areas of degraded habitat
or impaired habitat connectivity between the tributaries
and the lake are impacting native species. Contaminants
of emerging concern, such as microplastics, have been
detected.
Lake Michigan's ecosystem is in fair condition and
the trend is unchanging. Removal of contaminated
sediment and habitat improvement are occurring in AOCs;
White Lake has been formally removed from the list of
designated AOCs and management actions have been
completed at three other AOCs. Chemical pollutants have
declined significantly since the 1970s; however, fish and
wildlife consumption advisories remain in place. In some
nearshore areas, elevated phosphorus concentrations
are observed, whiie offshore phosphorus concentrations
are below objectives and continue to decrease. Diporeia
have almost disappeared, and filter-feeding by invasive
Lake Superior alone has 11.4 quadrillion litres (3 quadrillion
gallons) of water - enough to submerge North and South
America under 30 centimetres (1 foot) of fresh water.
Lake Michigan is home to the world's largest freshwater sand
dunes, attracting millions of visitors annually.
19
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Lake-by-Lake Snap Shot
Quagga Mussels has reduced the food available for prey
fish and the juveniles of economically important sport
fish (e.g. Yellow Perch) and commercial species (e.g. Lake
Whitefish). Record iow abundance estimates for most
prey fish populations, combined with increased natural
reproduction of predator fish, have prompted stocking
reductions for salmon and trout, cornerstone species for
the multi-billion dollar sport fishing industry. However,
in a few places, Lake Trout, the top native predator fish,
has shown signs of natural reproduction for the first time
in decades, due in part to the successful control of Sea
Lamprey.
Lake Huron's ecosystem is in fair condition and the trend
is unchanging. It has extensive beaches and its nearshore
areas provide excellent opportunities for swimming and
recreation. Chemical pollutants have declined significantly
since the 1970s; however, fish and wildlife consumption
advisories remain to protect human health. The majority
of nearshore waters are of high quality, but areas of
the southeast shore, Saginaw Bay, and parts of eastern
Georgian Bay experience periodic harmful or nuisance
algal blooms. Nutrient and algae levels in the offshore
are variable, but largely below targets. Zebra and Quagga
Mussels are associated with decline in nutrient levels and
nutrient availability to other aquatic organisms, increased
water clarity, nuisance algae growth and are suspected to
facilitate episodic botulism outbreaks in parts of the basin.
Diporeia, a major food source for prey fish, are declining,
resulting in negative consequences for recreational and
commercial fisheries. However, Walleye have largely
recovered in Michigan waters of Lake Huron and, in the
absense of the invasive Alewife, Lake Trout populations are
approaching reproduction targets.
More than 75,000 cubic metres (100,000 cubic yards) of
contaminated sediment were removed from White Lake resulting
in improved water quality and the return offish and wildlife
populations in Lake Michigan.
Lake Huron has the longest shoreline, including islands, of the
Great Lakes extending 6,159 km (3,827 miles).
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
20
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Lake-by-Lake Snap Shot
Lake Ontario's ecosystem is in fair condition and the trend
is unchanging. Contaminants in fish, such as PCBs, have
steadily decreased, leading to less restrictive consumption
advisories. Bald Eagles and Lake Sturgeon populations
are recovering. Native deepwater sculpin, a species once
thought extirpated, has recovered, while stocking efforts to
restore other native prey fish show some signs of success. The St. Clair River is home to the largest remaining Lake Sturgeon
As a result of two years of poor alewife reproduction, spawning population in the Great Lakes Basin,
reductions in salmon and trout stocking are needed to
address the potential imbalance between predators and
prey. Offshore phosphorus concentrations are below the
objective and declining nutrient levels may significantly
reduce the overall productivity of the lake and change the
structure of the lower food web, impacting fish production.
In the nearshore waters, despite long-term lake-wide
nutrient declines, mats of Cladophora are causing
problems in some areas due to high phosphorus levels
and/or increased water clarity and changes in nutrient
cycling following the arrival of the invasive dreissenid
mussels.
Nearly 7.5 million Canadians live in the Lake Ontario watershed,
making up almost 20% of the entire Great Lakes Basin population.
Lake Erie's ecosystem is in poor condition and the trend
is deteriorating. Harmful algai blooms resulting from
excessive nutrient inputs occur regularly in the western
basin and Lake St. Clair during summer, and have impacted
drinking water treatment systems. Beach closures, habitat
ioss and degradation, and beach fouling in the eastern
basin continue to be major concerns. Increased amounts
of decaying algae exacerbate seasonal anoxia (depleted
dissolved oxygen conditions) and hypoxia (low oxygen
conditons) in bottom waters of the central basin. Despite
the challenges, there are positive ecosystem trends,
including increased Walieye across the iake and Lake
Sturgeon in the St. Clair-Detroit River System; increased
aquatic habitat connectivity due to dam removal and
mitigation projects; and declines in Sea Lamprey wounding
offish since 2010. Since 2009, the western Lake Erie
Cooperative Weed Management Area partners in Ohio and
Michigan have treated more than 13,000 acres of invasive
Phrogmites, resulting in a 70% decrease in live Phragnnites
in Ohio and a resurgence of native plants in Michigan and
Ohio.
Lake Erie is the most biologically productive Great Lake, and it also
has the biggest sport fishing industry of all the lakes.
21
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT
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Participating Organizations
Many people have been involved with development of the State of the Great Lakes 2017 Highlights and Technical
Reports. Thank you to the authors and advisory committee members for their continued support.
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Ministry of the
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All photos included in this report are courtesy of U.S. federal agencies, Environment
Cover Photo and Pagel: © Getty Images
Lake Huron page 2, Lucas Van Landschoot
Drinking Water page 3, Ontario Ministry of Agriculture, Food and Rural Affairs
Wetland (bottom of) page 9, Michigan Sea Grant
Algae (bottom of) page 11, Stacey Cherwaty-Pergentile
Sea Lamprey page 13, Great Lakes Fishery Commission
Purple Loosestrife page 13, Michigan Sea Grant
Groundwater page 15, Norm Grannemann
Forest page 16, Stacey Cherwaty-Pergentile
and Climate Change Canada or are available for free use unless otherwise noted below:
Lake Superior (top of) page 19, Dave Crawford
Lake Superior (middle of) page 19, Nancy Stadler-Salt
Lake Michigan page 19, Michigan Department of Environmental Quality
Lake Superior (bottom of) page 20, jbailey/infosuperior.com
Lake Erie (top of) page 21, Michigan Sea Grant, Todd Marsee
Back Cover, jbailey/infosuperior.com
The State of the Great Lakes 2017 Highlights Report is a summary of science-based information from 44 sub-indicator reports.
These sub-indicator reports are included in their entirety in the State of the Great Lakes 2017 Technical Report. For more
information about the state of the Great Lakes reporting and to access the reports, visit the following websites:
www.binational.net
www.ec.gc.ca/greatlakes
www.epa.gov/greatlakes
STATE OF THE GREAT LAKES 2017 HIGHLIGHTS REPORT 22
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Cat, No.: Enl61-3E-PDF (Online)
ISSN; 2291-1138
Cat. No.: Enl61-3E (Print)
ISSN: 1924-0279
Aussi disponible en frangais
Etat des Grands Lacs 2017 Faits sail!ants
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