|
USFWS
Finds Ruffe in Lake Michigan's Escanaba Harbor
"Likely was transported
in ballast of commercial ship" says FWS
During a routine
Eurasian ruffe surveillance survey in Lake Michigan waters off Escanaba,
Mich., last week, U.S. Fish and Wildlife Service biologists captured and
destroyed an adult Eurasian ruffe. It was a 5" female found near the coal
dock in Escanaba Harbor. This is the first confirmed finding of a ruffe in
Lake Michigan.
The Eurasian
ruffe is an exotic invasive species first discovered in the Duluth, Minn.,
harbor and St. Louis River estuary of Lake Superior in 1986. Since then,
ruffe numbers in the Duluth harbor have increased to become the most common
species found while sampling with trawls. Their range has expanded into the
Wisconsin, Michigan and Ontario waters of western Lake Superior, and to one
location in Michigan waters of Lake Huron. Control measures have slowed
range expansion since 1995, but this recent invasion in Lake Michigan
indicates that ruffe are continuing to expand in the Great Lakes.
�Although the
effects ruffe will have on native Great Lakes fish populations are difficult
to predict,� said Mark Dryer, project leader for the Service�s Ashland
Wisconsin Fishery Resources Office. �Strong evidence suggests they compete
with native fish for food and space.� The ruffe is in the same family as
native yellow perch, walleye and some darters. In the Duluth harbor where
ruffe have become a dominate species, native species like yellow perch and
some bait fish have declined. Unfortunately, unlike native perch species,
ruffe have no known economic, recreational or environmental value
in North America.
Biologists are uncertain
about how the fish moved into Lake Michigan. It is possible, though
unlikely, that the fish naturally migrated from another location since they
were not previously found in Lake Michigan. However, it is more likely the
fish was transported in the ballast water of a commercial ship. Ballast
water exchange is believed responsible for the initial movement of ruffe
from their native habitat in Europe to the Duluth harbor. When a ship takes
on ballast water to stabilize a cargo load, aquatic species can be drawn
into the tanks and survive until they are released into a new area. Since
1993, the Great Lakes maritime industry has undertaken voluntary measures to
prevent ruffe from being spread in the ballast water of Great Lakes ships.
However, these voluntary actions may not be 100 percent effective.
The U.S.
Fish and Wildlife Service is the lead agency for the Ruffe Control Program
that was approved by the Aquatic Nuisance Species Task Force in 1995. The
Ruffe Control Program is a joint federal-state-tribal-private partnership
that is responsible for monitoring and controlling
ruffe populations. Since 1986, Service biologists have been
tracking the spread of ruffe by surveying shipping ports, tributaries and
coastal locations throughout the Great Lakes. The Ontario Ministry of
Natural Resources is also monitoring populations in the Canadian waters of
the Great Lakes.
U.S. Fish and Wildlife Service Regional Director
|
Bill Hartwig
is less concerned about how the fish arrived in Lake Michigan than what
needs to be done now. �It would be helpful to know how these fish got here
so we can expand measures to stop future movement,� said Hartwig. �But, the
more immediate issue is what we do about the ruffe now that they are here.
If they move into southern Lake Michigan, it is possible they could enter
the Mississippi River ecosystem through the Chicago Canal system.�
The Great Lakes
and Mississippi River ecosystems were artificially connected when the
Chicago Ship and Sanitary Canal was created in the late 1800s. In 2001, an
experimental electric barrier was installed in the canal near Romeoville,
Ill. Scientists believe an electrical current flowing through the waterway
will deter fish from using the canal to move between the Great Lakes and
Mississippi River ecosystems. �With round goby, and now Eurasian ruffe,
moving from the Great Lakes toward the Mississippi River, it is critical
that we ensure this barrier works,� added Hartwig. �When you also consider
that Asian carp are moving from the Mississippi River toward the Great Lakes
at the same time, we have the ingredients for an ecological disaster.�
U.S. Fish
and Wildlife Service Fisheries Assistant Regional Director Gerry Jackson has
recommended an increase in the Service�s ruffe monitoring and research
activities. �We will immediately begin discussing options with our partners
to increase monitoring efforts in Lake Michigan to determine the size and
range of this new ruffe population.� Currently, there are no practical
methods available to eliminate ruffe populations in the Great Lakes. �Our
best approach now is to identify new populations through surveillance so
measures to control their spread can be focused. We need to contain
existing populations and at the same time increase our research efforts to
develop safe and effective methods to control the spread and impact of this
and other aquatic nuisance species,� added Jackson.
The Service plans to continue
working with federal, state, tribal and Canadian agencies, recreational
anglers and boaters, the Great Lakes shipping and bait-fish companies,
private industries and federal task forces to develop innovative methods to
inform people about aquatic nuisance species and what they can do to help
control the expansion of these nuisance fish.
The 1990
National Aquatic Nuisance Protection and Control Act (NANPCA), as amended by
the National Invasive Species Act of 1996 (NISA), established the Aquatic
Nuisance Species (ANS) Task Force to develop a cooperative ANS Program and
coordinate all new ANS activities that are conducted, funded, or authorized
by the Federal Government. The ANS Task Force is co-chaired by the U.S.
Fish and Wildlife Service. The Service�s ANS Program supports NANPCA and
works with others to implement ANS Task Force Program elements so that some
exotic species are prevented from invading the United States and, when
populations invade, they are monitored and controlled as best possible.
For more info contact:
Mark Dryer, 715-682-6185 x201 or Chuck Traxler, 612-713-5313 |
