[Date Prev][Date Next][Date Index]

GLIN==> Sea Lampreys in the St. Marys River (news release)



Great Lakes Fishery Commission

For Immediate Release
December 2, 1999
Contact:  Marc Gaden
734-662-3209 x. 14

International Effort Eliminates Nearly Half of the 
Sea lampreys in the St. Marys River

Future Much Brighter for Lake Huron Fish

	After an extraordinary international effort, the Great Lakes Fishery
Commission today announced that preliminary assessments show significant
reductions in sea lamprey larvae populations in the St. Marys River.  The
reductions are the result of a large-scale Canadian and U.S. control efforts
there this past summer.  The announcement came following reports from
Fisheries and Oceans Canada, the U.S. Fish and Wildlife Service, and the
U.S. Geological Survey, who assessed and carried out the St. Marys River sea
lamprey control this past July.   Their data indicate that the lampricide
treatment eliminated nearly half of the sea lampreys in the St. Marys River.
They also achieved a significant increase in trapping and
sterile-male-release.  The integrated lampricide, trapping, and
sterile-male-release puts the Commission on-track to eliminate 92% of the
sea lampreys produced in the river, thereby achieving the goal of reducing
parasitic lampreys in Lake Huron and northern Lake Michigan by 85% over the
next 15 years.

	Sea lampreys invaded the Great Lakes in the early part of the 20th
Century through shipping canals.  Their impact on the valuable fishery was
immediate and devastating:  fish harvest declined dramatically and the
thriving fish communities, based on native, self-sustaining fish stocks,
were thrown seriously off balance.  In 1955, the governments of Canada and
the United States created the Great Lakes Fishery Commission to control sea
lampreys.  Since then, the Commission has suppressed sea lamprey populations
in most areas by 90%, paving the way for successful stocking, rehabilitation
of native fisheries, and the resurgence of sport and commercial fishing.
Despite this success, the St. Marys River remained a major trouble spot in
the Great Lakes, producing more sea lampreys than all of the other Great
Lakes combined.  These lampreys migrated downstream and feed on large
numbers of fish in Lake Huron and northern Lake Michigan.  Control on the
St. Marys River had been elusive because of the river's size, tremendous
flow volume, and a lack of funds to do the job.  

	In 1997, after careful planning and a $3 million contribution from
the State of Michigan, the Commission started control on the river with a
multi-faceted attack on the sea lampreys inhabiting the river. They began
with an all-out effort to suppress successful spawning by stepping up
trapping efforts, removing females, and annually releasing tens of thousands
of sterilized male sea lampreys.  In 1998 and 1999, the commission added the
most ambitious element of the plan, application of a granular,
bottom-release formulation of the lampricide Bayluscide.  Those applications
were directed only at areas of high lamprey density, selected after sampling
more than 12,000 sites across the river during 1993-1996.

	"Preliminary assessment data show the 1999 treatment was a
tremendous success, meeting or exceeding expectations in all significant
areas," said Commissioner Roy Stein of Ohio State University.  "In the plots
treated with lampricide-which amount to a very small percentage of the
river's surface area-an estimated 88% of the sea lamprey larvae were
removed.  Previous field estimates predicted 75% removal.  On a whole-river
level, the lampricide spot treatments have eliminated 45% of the sea lamprey
larvae, close to the 50% removal rate originally predicted."

	Stein continued:  "We also have had great success with trapping and
the sterile-male-release initiative.  With the fully functioning new trap at
the U.S. Corps of Engineers facility in Sault Ste. Marie, Michigan, and with
further refinements to the Great Lakes Power trap in Sault Ste. Marie,
Ontario, we increased overall trap effectiveness from 40% during 1998 to 56%
in 1999.  That means 56% of the estimated 20,000 spawning sea lampreys in
the St. Marys River were removed through traps alone."  

	"With the increased harvest of sea lampreys in the St. Marys, along
with lampreys trapped in other locations, agents were able to release 26,000
sterilized male sea lampreys in the river, achieving a ratio of 4.7
sterilized males for every fertile male," said Commission Chairman Burton
Ayles.  "This is a large increase from the 2.2 to 1 ratio achieved during
1997.  This is also much greater than the ratio of 3 to 1 used in our
forecast.  Together, the integrated trapping and sterile-male-release
efforts are estimated to have reduced the reproductive potential of the St.
Marys River by a remarkable 92%."

	"We are greatly encouraged by the results of the St. Marys River
treatment," Ayles continued.  "The men and women who carried out the
treatment should be congratulated for their efficiency and effectiveness.
The benefits to the Lake Huron and northern Lake Michigan fish communities,
and to the millions of people who fish the Great Lakes, should be felt
within the next few years.  Assessment is critical now; we need to keep
close tabs on our progress.  The Commission will remain vigilant and will
continue to aggressively control the St. Marys River sea lamprey populations
until our 85% reduction goal is reached." 

--30--
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
glin-announce is hosted by the Great Lakes Information Network:
http://www.great-lakes.net
To search the glin-announce archives:
http://www.great-lakes.net/lists/glin-announce/index.html
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *