This winter's
frigid
temperatures
have produced
the largest
amount of ice
cover on the
Great Lakes
in at least 25
years.
Nearly 60%
of the lakes
are now under
a cover of ice,
according to
the Great Lakes Environmental
Research
Laboratory in
Ann Arbor, Mich.
The ice cover
could help lake
levels this
summer, but
that is far
from certain.
And biologists
are keeping a
close eye on
northern Lake
Superior in
the hope that
an ice bridge
will link Ontario
to Isle Royale.
The island
is the home
to a
struggling
gray wolf
population
in desperate
need of new
genetic
stock — and
more wolves.
57% of Lake
Superior is covered with ice.
As the deepest of the Great
Lakes, Leshkevich s
aid, Lake Superior takes more
sustained cold air to freeze,
and because it produces
considerable wave action
from prevailing westerly
winds, ice is slower to form.
Researcher Jay Austin of
the University of Minnesota-
Duluth says the ice "acts like
a giant piece of plastic" over
the lake. That means water
can't evaporate as readily
from sunlight.
On Isle Royale, as late as
Thursday, wolf researcher
Rolf Peterson of Michigan
Tech said by email that he
could still see gaps in the
ice and it was premature
to say a bridge had formed.
Biologists hope that
will happen — the last
time was 2008. If ice
from Ontario stretches
to the island, it could
mean the introduction
of new wolves, which
could help boost the
population and diversify
the gene pool.
The last time a wolf migrated
across the ice was 1997.
The wolf population on the
island dropped from 16 in
2011 to eight in 2013.
In their
first 2014 post from
the island on Jan. 12,
researchers from Michigan
Tech tracking the wolf and
moose population on the
island wrote:
"If climate projections are
accurate, only one or two
more ice bridges are likely
before the lake is expected
to be perpetually free of
any significant ice formation
(by 2040.)
"Ice bridges are important
because they represent the
possibility that a wolf can
migrate from Canada and
infuse the population with
new genetic material —
this appears vital for the
population's vitality."