Great Lakes Need More Scientific Attention
Larry Oakes Star Tribune Northern Minnesota
21, 2002 LAKE21
-- Ten of the world's largest lakes, including North
America's Great Lakes,
contain two-thirds of the world's surface fresh water,
and some intriguing unsolved mysteries to boot.
With that in mind, a group of 20 scientists
gathered in Duluth
last week beside the biggest lake of them all -- Lake
Superior -- and reached this consensus:
Faced with threats that include global
warming, exotic-species invasions and a growing shortage
of potable water in dry regions, the United
States has a vital interest
in making sure these lakes get more scientific attention.
"Fresh water is becoming increasingly
scarce," said John Janssen, a senior scientist at
the University of Wisconsin-Milwaukee's Water Institute.
"The people around the Great
Lakes largely take this water wealth for granted,"
Janssen said. "That will change quickly."
Scientists also are intrigued by such
mysteries as the origin of strong currents, described
by some as underwater storms, that
periodically scour the bottom of Superior
and other large lakes.
Prof. Thomas Johnson, director of the
Large Lakes Observatory at the University
of Minnesota Duluth,
host of the conference, said: "The amount the National
Science Foundation spends on large-lake research is less
than 1 percent of what it spends on oceans. We think that's
a major mismatch."
Scientists who study lakes and ponds
came to the conference from 15 universities and several
scientific institutes around the country. They agreed
at the end of the three-day event to ask the National
Science Foundation, administered by the federal government,
to create a new program specifically to fund large-lake
The foundation appears willing at least
to listen: it sponsored the conference and asked for recommendations
from the scientists.
Besides the Great Lakes,
bodies of water the researchers have in mind include Lake
Baikal in Russia
and several large lakes, such as Victoria
in the East Africa's Rift Valley.
Scientists say the most immediate need
is for more underwater observation buoys designed to gather
data on changes in temperature, currents and the levels
of certain nutrients and chemicals.
observatory has only two such buoys, but would like more.
They carry close to $100,000 worth of equipment and are
anchored 50 feet below the surface, where they record
data until they are retrieved by the observatory's research
vessel, the Blue Heron.
Scientists on the vessel use a radio
signal to activate an "acoustic" release that
allows the buoy to surface so they can pick it up. The
acoustic release alone costs $8,000, Johnson said.
The data these buoys collect can help
construct models that could predict such things as what
would happen to a lake's ecosystem if part of its water
were siphoned off, if pollutants continued to accumulate
in the water or if climate change caused a lake to warm
Lakes that sing
Several scientists said that large lakes,
like canaries in a mine, can give vital early clues to
what may be happening to the environment in their parts
of the world and what trends may be affecting the globe.
"Beyond the ways in which large
lakes are important for their own sakes, they are also
extremely valuable diagnostics of changes that are imposed
on them from their surroundings," said Prof. Ray
Weiss of the Scripps Institution of Oceanography at the
Their size and relative isolation make
them good yardsticks of long-and short-term changes in
climate, aquatic life and pollution, he said.
"Actually, the canaries have been
the smaller bodies of water, which have suffered impacts
sooner," Janssen said. "Now the impacts, and
different ones, are hitting the Great Lakes.
In terms of surface fresh water, this is the end of the
"In terms of oceans, they are
Each scientist came with his or her wish
list of top research priorities. Janssen, a biologist,
wants more money devoted to the study of water quality
and the natural sources of food for fish. He noted that
many commercial fisheries on the lakes have been destroyed,
and much information is needed if they are to be restored.
Prof. Hans W. Paerl of the Institute
of Marine Sciences
at the University
of North Carolina
wants to see more nutrient, sediment and "water column"
studies that might help differentiate between natural
and human-caused climate changes.
Proliferating exotic species such as
zebra mussels, which probably entered the Great
Lakes in ships' ballast water, are worrisome
to the scientists.
"I don't think our research can
prevent exotic species, but it can give us a better ability
to predict what will happen when they show up," said
Johnson of the Duluth
Talk about the problems of global warming
and exotic species sometimes eclipses the other reason
Johnson sees for gathering more data: exploration.
"All of us feel there are wonderful
mysteries in these lakes that the public would like to
know more about," he said.
For example, data on currents may help
solve a mystery known to scientists and Lake
Superior fishermen alike: those underwater
storms that sweep the sediment from lake bottoms and tug
at fishing nets, even on a dead calm day.
"We see the erosional features but
have no idea how frequently they happen or how strong
they are," Johnson said.
Another mystery is why Lake
Superior periodically produces blooms of zooplankton,
an important source of food for fish, in patterns thus
far hard to predict.
"We think there are bumper-crop
years and years of crashes," Johnson said. "How
often and why that happens have obvious implications for
-- Larry Oakes is at email@example.com.