detected in Lake Erie
Just when environmentalists were
gaining hope, mysterious void emerges in basin's deepest
Lake Erie may be dying once
A team of American and Canadian
scientists aboard the research vessel Lake Guardian is
out on Lake Erie trying to determine why its chemistry
has unexpectedly changed, creating a large ``dead zone''
in the deepest water of the central basin between Sandusky
and Erie, Pa.
Excessive phosphorus in the
water -- a condition that existed in the lake in the 1960s
-- has left the zone devoid of dissolved oxygen needed
by fish and aquatic insects.
Should the phosphorus problem
persist, the result could be massive fish kills, damage
to Ohio's thriving walleye fishery, a threatened tourist
industry, fouled swimming beaches and bad-tasting and
bad-smelling drinking water in communities such as Cleveland
that draw their water from the lake.
The phosphorus has yet to
trigger massive algae blooms that lead to such problems,
and scientists don't know why that hasn't occurred. But
decaying algae washed up on beaches in Vermilion and Erie
``It's the beginning of the
second environmental war on Lake Erie,'' said U.S. Environmental
Protection Agency scientist David Rockwell. ``It's a very
serious problem, and it could be a really big problem....
The brakes we thought we had on the system aren't working
Mussels are suspects
The excessive phosphorus may
be caused by zebra and quagga mussels changing the lake,
the experts say.
Research is under way by a
team of nearly 30 scientists from 17 universities headed
by Gerald Matisoff of Cleveland's Case Western Reserve
As part of a $2 million, two-year
study, the 200-foot Lake Guardian, which is owned by the
EPA, is making its third seven-day voyage of the summer.
Another trip could be scheduled this fall.
Phosphorus levels have been
rising since 1995. Algae has been increasing since 1997,
and dissolved oxygen has been dropping to levels that
threaten fish, plankton and aquatic insects in the central
If those trends continue for
another three years, Lake Erie could face 1970s-style
problems, says Lake Erie expert Jeffrey Reutter of Ohio
``That's a bad thing and a
bad trend,'' he said. ``It's not the end of the world...
but it means we're going to have to devise a new plan
to manage the lake.''
Scientists are concerned because
everyone had thought the lake was getting cleaner. Then
it became apparent that thedecades-old phosphorus problem
had reappeared. ``It hasn't improved the way we thought
it would,'' said U.S. EPA scientist Paul Bertram.
Scientists fear that the dead
zone is a sign that environmental improvements in the
lake have been reversed, although they don't understand
what's happening or how it's occurring. No one has a remedy
for the problem.
Zone appears in 2001
The dead zone surprisingly
appeared in 2001 in the 6,300-square-mile central basin.
It was the largest such zone to show up in the lake since
the early 1980s.
This year, the zone reappeared.
At the worst point, in late August, 90 percent of the
central basin didn't have enough dissolved oxygen in the
deepest waters. Although bad, that was an improvement
over a year earlier, Rockwell said.
The zone does not appear in
the lake's shallower western end or in the deeper eastern
end. It disappears in the fall when the waters naturally
Scientists from the U.S. EPA,
Environment Canada and the universities are trying to
find the answers to a few key Lake Erie questions:
Why is there again
a dead zone in the summer?
Why is phosphorus
in the water increasing when the amount of phosphorus
going into the lake isn't increasing?
Why is chlorophyll
-- an indicator of algae -- at historically low levels?
Are the mussels filtering out and feeding on the algae?
``We have tracked Lake Erie
for decades and thought we had a good historical understanding
of what to expect now and in the future,'' said EPA spokesman
Thomas Skinner. ``But the recent discovery of sudden biological
changes, which could have long-term effects on the ecosystem,
prompted this all-out investigation.''
Other topics of research include
global warming and ultraviolet light, whether the mussels
eat the algae before it blooms into massive floating mats,
and whether floating petroleum products could be limiting
Case Western Reserve's Matisoff
said it will probably be late this year before preliminary
data from the research is released and next year before
the results will be finalized.
Reutter said the lake's oxygen
problem appears to be growing.
``We believe it is caused
by excess phosphorus,'' he said, ``but we also believe
zebra mussels and quagga mussels are having an impact
because they appear to alter the way phosphorus cycles
through the system.''
Phosphorus from farm runoff
and sewage plants is carried into the lake by storm water
and rivers. It's a nutrient for algae, which grows, dies
and sinks to the bottom to rot. Bacteria feeding on the
rotting algae remove needed oxygen from the water.
Past cleanup efforts
In the mid-1960s, national
publications, including Life magazine, declared that Lake
Erie, filled with blankets of algae, was dead. But the
lake wasn't dead -- it was over-enriched with phosphorus.
In 1969, nearly 30,000 tons
of phosphorus went into Lake Erie. By the mid-1990s, that
amount had been cut to 11,000 tons under a U.S.-Canadian
An estimated $8 billion was
spent to upgrade sewage treatment plants to reduce the
amount of phosphorus going into Lake Erie.
In 1990, Ohio banned the sale
of high-phosphorus laundry detergents in 32 counties that
drain into the lake.
The phosphorus problem appeared
to have gone away, only to reappear.
In a congressional hearing
in August in Cleveland, Ohio State researcher David Culver
blamed the new phosphorus problem on the growing number
of quagga and zebra mussels in the lake.
Both species release phosphorus
as waste, but the quagga, a thumb-sized clam, may be the
bigger culprit. It produces more phosphorus than the zebra
mussel and outnumbers its cousin in the central basin.
Zebra mussels were found in
Lake Erie in 1988, and quaggas were discovered in 1992.
The quaggas prefer water at least 30 feet deep, while
zebra mussels are found in shallower water.
Both entered the Great Lakes
from Europe in freighter ballast water. Such water is
used to stabilize freighters and is discharged when ships
arrive at their destinations. Ballast water may contain
animals and plants from the home port that end up being
transported around the world. The United States and Canada
now ban ballast-water dumping.
If mussels are determined
to be the problem, there is no way to remove them from
Lake Erie, Culver said.
The only solution, experts
say, would be to curtail phosphorus from farm-fertilizer
runoff, from combined sewers such as those in Akron and
Cleveland, and from high-phosphorus dish-washing soaps.