STATE  OF THE  GREAT LAKES
             WHAT IS THE STATE OF THE GREAT LAKES ALVARS AND
                                    COBBLE BEACHES?
Alvars and cobble beaches are important special features of the Great Lakes region that contribute greatly to the
diversity of the region by providing unique habitats for rare, and in some cases threatened or endangered, plant
 and animal species. Human activities, such as shoreline development and agriculture, are putting these special
                                       communities in peril.
The Issues
•  Over two thirds of known alvar occurrences in
   the Great Lakes region are close to the shoreline,
   with all or a substantial portion of their area
   within 1 km of the shore. These communities are
   naturally open habitats occurring on flat
   limestone bedrock and while it is likely that
   they have always been sparsely distributed,
   more than 90 percent of their original extent has
   been destroyed or degraded by human uses.

•  Shaped by wave and ice erosion, cobble beaches
   provide valuable seasonal spawning and
   migration areas for fish as well as nesting areas
   for the piping plover, a bird species listed as
   endangered by the United States and Canada in
   the Great Lakes. As a result of shoreline
   development, cobble beaches are becoming so
   scarce that they are considered globally rare.

The Indicators
Alvars and cobble beaches are important features of
the Great Lakes region. They both support a diverse
array of plant and animal species, and a number of
these species are unique to these environments. For
example, lakeside daisy and the beetle Chlaenius p.
purpuricollis, have nearly all of their global
occurrences within Great Lakes alvar sites. For this
reason the presence of undisturbed alvar and
cobble beach sites is an important indicator of the
health and diversity of a number of species. In
addition to supporting ecologically distinct
communities, their deterioration and disappearance
illustrates the impact of development and other
human practices, such as  agriculture, on the
biological integrity of the Great Lakes.
The Assessment
A four-year study of Great Lakes alvars was
conducted in the 1990s to evaluate conservation
targets for alvar communities. The study concluded
that essentially all of the existing alvars should be
maintained since all alvar community types are
below the minimum viable threshold.

Of the remaining alvar communities in the Great
Lakes region, approximately 64 percent are located in
Ontario, while 35 percent are located in the Great
Lakes states. Several different community types occur
within each alvar site and six of these community
types show a strong association with nearshore
settings. The current protection status of all nearshore
alvar communities was evaluated by analyzing
current land ownership and the type and severity of
threats to alvar integrity. It has been determined that
less than 20 percent of the nearshore alvar acreage is
currently fully protected, while over 60 percent is at
high risk.
                                                   Chaumont Barrens Alvar Grassland, New York. Photo:
                                                   U.S. EPA Great Lakes National Program Office.

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    ALVARS AND COBBLE BEACHES
Lake Superior has the largest cobble shoreline of all
the Great Lakes, followed by Lakes Huron,
Michigan, Ontario, and Erie (Table 1). The number
and area of cobble beaches are decreasing due to
shoreline development. A wide variety of
vegetation surrounds cobble beaches and the cobble
beaches themselves also serve as a home to plants
that are unique to the Great Lakes shoreline,
including the endangered heart-leaved plantain
found on the cobble beaches of Lake Superior.

Current Actions
The documentation of the extent and quality of
alvars has allowed for much greater public
awareness and conservation of this important
resource. In recent years, a total of 10 projects have
resulted in the protection of at least 2140 hectares of
alvars across the Great Lakes region, with 1353
hectares located within the nearshore area. These
projects have increased the area of protected alvars
dramatically in a short time.

Actions Needed
The status of alvars and cobble beaches must to be
closely monitored to ensure that they are not lost.
Major binational projects hold great promise for
further progress in alvar protection, but there is still
a large area of unprotected alvars in Ontario. More
research is needed for cobble beach communities to
develop baseline data. Topics to investigate include
the percentage of cobble beaches that already have
homes on them or are earmarked for development
and the percentage of cobble beaches that are in
protected areas. Finally, we need a more detailed
 Table 1. Length and percentage of total shoreline comprised by cobble beaches for each
 of the five Great Lakes.
                    Miles of       Kilometers of    Percent of Total
                  Cobble Beach    Cobble Beach       Shoreline
 assessment of the location of remaining cobble
 beaches and the plant and animal life that they
 support.

 To Learn More
 For further information related to Great Lakes alvars
 and cobble beaches, 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.
                 .'_,-jpf^.-:
spi^fsiasp?^,
Great Lakes cobble beach. Photo: U.S. EPA Great Lakes
National Program Office.
Lake Superior
Lake Huron
Lake Michigan
Lake Ontario
Lake Erie
595
300
102
22
16
958
483
164
35
26
20%
9%
6%
3%
2%
                                                                                             02/06
                                                                                    EPA 905-F-06-905
                                                                                    IISG-05-31

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