STATE  OF  THE GREAT LAKES 2005
       WHAT ARE THE CURRENT PRESSURES IMPACTING LAKE HURON?
  Chemical contamination, non-native invasive species, habitat loss, poor coastal health, and aquatic food web
                      changes are the greatest threats to the Lake Huron ecosystem.
Pressures
Chemical contamination
Contaminants enter Lake Huron through a variety of
pathways including industrial and municipal
discharges, land runoff, atmospheric deposition, and
contaminated sediments. Lake Huron has relatively
few local contaminant point sources but has a large
surface area which makes it vulnerable to
atmospheric deposition of contaminants.
Contaminant levels in fish and wildlife have
decreased substantially since the 1970s and
populations of most fish-eating birds have recovered;
however, fish consumption advisories for PCBs still
exist for the open lake and for all Areas of Concern
(AOCs) in Lake Huron.

Non-native invasive species
The recent invasion of zebra and quagga mussels,
round goby, spiny water flea, white perch and ruffe
threaten the diversity and abundance of native
species and the ecological stability of Lake Huron.
Abundance of Diporeia, a key prey item in the diet of
whitefish and other sport and commercial fish
species, has drastically declined in Lake Huron,
possibly due to competition with non-native invasive
species. The invasive sea lamprey remains prevalent
in Lake Huron, but intensive control efforts in the St.
Mary's River (the largest source of sea lampreys in
the Great Lakes) since 1999 have reduced the impacts
of sea lamprey predation on salmon and lake trout.

Habitat loss
The Lake Huron watershed, home to about 2.5
million people, has relatively low human population
densities. As a result, Lake Huron retains much of its
historic fish and wildlife habitat. Historically, Lake
Huron was connected to a diverse array of stream
and inland lake tributaries that provided spawning
habitats for many fish species. Construction of dams
  Lake Superior
                          Lake Huron
   Lake Michigan
                                    Lake Ontario
                              Lake Erie
and hydroelectric facilities in the 1800s, however,
excluded fish from many historical spawning sites.
For lake sturgeon, walleye, chinook salmon and other
river spawning fish, stream fragmentation reduces
natural reproduction and increases dependence on
fish stocking. Water level fluctuation patterns also
alter nearshore habitat. Although residential land use
comprises a small percentage of total land use in the
Lake Huron region, much rural development has
occurred along the shoreline. In the past 20 years
there has been increasing development pressure for
cottages and year-round residential development,
which poses a threat to nearshore habitats.

Coastal health
For many years, elevated levels of E. coli bacteria have
caused numerous postings of Lake Huron beaches as
unsafe for swimming. Multi-jurisdictional efforts are
                                                   Fathom Five National Park, Canada. Photo: Environment
                                                   Canada.

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       LAKE HURON PRESSURES
underway to identify significant sources and
encourage land-owner best management practices to
reduce bacteria levels and the risk to human health.
Also, as in Lakes Erie and Ontario, outbreaks of Type
E botuism bacterium have killed thousands of fish
and waterbirds in Lake Huron, which wash up on
area beaches. The sources of this bacterium and
causes of the outbreaks are being studied.

Aquatic food web
Lake trout, burbot, and walleye were the original
main fish predators in Lake Huron. Lake herring,
cisco species, sculpins, lake trout and round
whitefish comprised the historic prey base. Today,
stocked chinook salmon is the dominant predator in
the lake, primarily feeding on the dominant, non-
native alewife and smelt prey fish.  Since the 1960s,
chinook salmon and lake trout have been stocked in
the Great Lakes to create sport fisheries and to reduce
the huge populations of alewife and smelt. The
current ecosystem now contains more predators than
prey species, and is at risk of becoming unstable.
While markedly different from historical fish
communities, fish management efforts have resulted
in a much improved fish community than  was
present 30 to 40 years ago. Drastic  changes in the
Lake Huron fish community were  noted in 2004:
while Saginaw Bay had huge year  classes of walleye
and yellow perch, the open water fishery is suffering
from the collapse of alewife and major declines of
Diporeia in the Main Basin and Georgian Bay.

Current Actions
In 2002, the Binational Executive Committee, a forum
of executive-level representatives of U.S. and
Canadian natural resource management and
environmental protection agencies, chaired by U.S
EPA and Environment Canada formally endorsed the
formation of a Lake Huron Binational Partnership in
order to coordinate environmental activities in the
Lake Huron basin. The U.S. EPA, Environment
Canada, Michigan's Departments of Environmental
Quality and Natural Resources, and Ontario's
Ministries of Environment and Natural Resources
form the core of the Partnership by providing
leadership and coordination. However, a flexible
membership is being promoted which is inclusive of
other agencies and levels of government, Tribes/First
Nations, non-government organizations and the
public on an issue-by-issue basis.

In 1987, four AOCs were identified within the Lake
Huron watershed, as well as the  St. Marys River.
Collingwood Harbour and Severn Sound in Canada
were delisted in 1994 and 2003, respectively.
Monitoring is ongoing in these areas to ensure that
environmental quality is maintained. The remaining
AOCs (Saginaw River/Bay, Michigan and Spanish
Harbour, Ontario) are being addressed through on-
going programs. At the Spanish Harbour AOC, all
recommended actions were completed and in 1999,
the area was the first in the Great Lakes to be
recognized as an Area in Recovery.

Actions Needed
   •  Support for local efforts that protect areas of
      high-biodiversity from future degradation
   •  Continued strong domestic programs to restore
      and protect tributary and nearshore health
   •  Continued support for the Great Lakes Fishery
      Commission's binational approach to address
      recent changes in the open water food web
   •  Support for the restoration of the remaining
      Areas of Concern
   •  Demonstration projects to restore the
      connectivity of tributaries with the open water,
      such as dam removal and/or fish passageways

To Learn More
For further information related to the state of Lake
Huron, refer to the State of the Great Lakes 2005
report, which, along with other Great Lakes
references, can be accessed at
www.epa.gov/glnpo/solec. The 2004 Lake Huron
Binational Partnership Action Plan can be accessed at
http://cfpub.binational.net/ontario/intro-e.cfm.
                                                                                                  02/06
                                                                                        EPA 905-F-06-914
                                                                                        IISG-06-07

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