Biological Pollution Threatens
Minneapolis Star Tribune
WASHINGTON, D.C. -- While industrial pollution of the
Great Lakes has diminished and overall water quality has
improved, new forms of biological pollution such as zebra
mussels and Asian carp are threatening the lakes, a government
scientist said in a Capitol Hill briefing Tuesday.
The mixed review of efforts to clean up the Great Lakes
came from a panel of federal, state and nongovernmental
scientists organized under the State of the Lakes Ecosystem
Conference, which includes Canada, Minnesota and seven
other Great Lakes states.
"We've still probably got a long way to go in figuring
out how to solve those problems," said Paul Horvatin,
of the Environmental Protection Agency's (EPA) Great Lakes
National Program Office in Chicago.
On the plus side, scientists see self-sustaining lake
trout stocks in Lake Superior, successful nesting programs
for bald eagles, a general decline in toxic substances
such as polychlorinated biphenyls (PCBs) and lower levels
of phosphorus in all the lakes except Lake Erie.
On the minus side, non native and invasive species constitute
a growing threat to the Great Lakes ecosystem, prey-fish
populations are down in some parts of the lakes, and E.
coli and fecal coliform levels remain a problem in some
near-shore recreational waters, particularly in Lake Erie.
Moreover, future population and development pressures
are likely to tax the lakes' overall biodiversity, said
John Andersen, director of the Nature Conservancy's Great
"Biodiversity is the foundation of everything we
enjoy in the Great Lakes," he said.
Though toxin levels in the lakes have been reduced since
the 1972 Clean Water Act and the 1976 ban on PCBs, all
five Great Lakes continue to have fish advisories.
For example, the Minnesota Health Department recommends
no more than one meal per month of medium-sized Lake Trout
or Chinook Salmon caught in Lake Superior.
Much of the concern behind those advisories are PCB levels
in fish, though those levels are declining in Lake Superior,
the most pristine of the Great Lakes.
"For Lake Superior, in general, the advice has become
less restrictive," said Patricia McCann, of the Health
Department's Health Risk Assessment Unit.
But mercury levels and new emerging contaminants remain
an unknown in Lake Superior and the other lakes, prompting
calls for a more coordinated effort to monitor their overall
A recent General Accounting Office report said that the
states' efforts to track pollution threats are largely
inconsistent and uncoordinated and that the EPA lacks
the authority to impose an overarching Great Lakes strategy.
Legislation introduced in May by Sen. Carl Levin, D-Mich.,
authorizes $28 million over four years for a coordinated
EPA monitoring program. "There has to be a central
effort," Levin spokeswoman Amber Jones said.
Levin's bill is being championed by the Northeast-Midwest
Institute, a Washington-based nonpartisan group that sponsored
Tuesday's Capitol briefing.