Page 12 - aruba-today-20220208

A12 science
Tuesday 8 February 2022
Scientists race to gather winter data on

warming Great Lakes

By JOHN FLESHER
AP Environmental Writer
TRAVERSE CITY, Mich. (AP)
— What's happening in the
Great Lakes during those
long, frigid months when
they're often covered par-
tially or completely with
ice? A casual observer —
and even experts — might
be inclined to say, "Not
much."
Lake scientists have long
considered winter a sea-
son when aquatic activity
slows. Most do their field
studies at other times of
year. Ice builds on Lake Michigan along the shore at Newport State
But researchers now think Park in Wisconsin, Feb. 15, 2021.
more is going on in the bit- Associated Press
ter depths than previously mum ice cover. food web or contribute to
believed — including ac- They'll take what Ozersky harmful blooms."
tivity influenced by climate described as a midwin- One reason for growing in-
change. To learn more, ter "snapshot," measuring terest in winter's effects on
teams will venture onto the characteristics such as light the lakes is how winter itself
frozen surfaces of all five levels at different depths, is changing.
lakes this month to collect water movement and the Great Lakes ice cover has
water samples and other presence of carbon, bac- declined steadily since
information from below the teria and nutrients that the 1970s and some pro-
ice. "We've been ignoring feed fish but also can dam- jections indicate it could
winter on the Great Lakes age the environment. become scarce later this
for so long," said Ted Ozer- University of Michigan bio- century.
sky, a lake biologist with the geochemist Casey God- While that might boost the
University of Minnesota Du- win will explore Lake Hu- cargo shipping industry,
luth, who announced the ron's Saginaw Bay, where the results for lake ecology
"Winter Grab" expedition phosphorus overloading are unknown.
Thursday. has fueled harmful algae Ice is "a dramatic physical
"There are lots of ways outbreaks that also plague force," Ozersky said, influ-
in which ice and winter Lake Erie. He and col- encing everything from the
conditions can affect the leagues have gathered a exchange of carbon diox-
ecosystem. We don't fully lot of data from the bay, ide between air and water
understand all of them. but almost none in winter, to light penetration and
We have a general idea he said. the water column's thermal
of how it should work but Although algae blooms structure. Such character-
in many cases we haven't are generally considered istics can determine how
done the footwork to see," a summer problem, satel- much plankton is available
Ozersky said. lite imagery has detected for fish.
Crews from more than a them in Lake Erie's central Nearshore ice can pro-
dozen U.S. and Canadian basin during cold periods, tect fish eggs and prevent
universities and govern- Godwin said. crashing waves from erod-
ment agencies will make "I'm especially interested ing shorelines.
their way onto frozen sec- in what forms of phospho- "We know it's important
tions of lakes Erie, Huron, rus are present in the water but because we haven't
Michigan, Ontario and during wintertime," he said. studied it, there are many
Superior during the week "We have ways of char- areas where we don't fully
of Feb. 14. That's typically acterizing whether it's the understand the effect of
around the time of maxi- type that can support the having or not having ice,"
Ozersky said.
The institute sponsored
a 2019 meeting of spe-
cialists worried about the
shortage of winter data as
global warming boosts air
temperatures, reduces ice
cover and alters snow and
rain patterns across the gi-
gantic watershed that ex-
tends from Minnesota to
the mouth of the St. Law-
rence River in Quebec.q