Deadly toxin could hit Lake Ontario by autumn, scientists
Sunday, August 06, 2002
TORONTO (CP) - Scientists in Canada and the United
States are keeping a close eye on Lake Ontario this
summer as thousands of dead fish and birds continue
to wash up on the shores of Lake Erie.
For the third consecutive year, fish and bird carcasses
have littered beaches along Lake Erie on both sides
of the border, leading researchers to believe a potentially
deadly toxin, created by type E botulism, is to blame.
Jeff Robinson, a biologist with Environment Canada,
says this epidemic appears to be travelling east and
is poised to hit Lake Ontario by autumn - a serious
threat to any wildlife that travels south for the winter
via Lake Ontario.
"Botulism bacteria is becoming more mobile," Robinson
said. "And there's really not a lot we can do."
During the past two weeks, dead birds have been found
on the American side of Lake Ontario, worrying scientists
who fear the situation is getting worse.
The suspected cause of the problem is botulism, a
naturally occurring bacteria that arrived about 10 years
ago when ships from the Caspian Sea introduced exotic
species into the Great Lakes.
The exotic species, particularly the zebra mussel,
brought the botulism, which effectively creates a dangerous
The theory scientists are probing is that the goby,
a fish that dwells at the bottom of the lakes, is eating
the zebra mussel and dying from the toxin. The toxin
is suspected of effectively climbing the food chain
to other fish, fish-eating birds, ducks and even a small
number of eagles.
Tests conducted on some of the tens of thousands of
fish and bird carcasses found in and around Lake Erie
have shown evidence of toxic poisoning.
The toxins pose a potential health risk to people
who could become seriously ill if they don't cook their
fish thoroughly enough to eliminate any bacteria, said
Bill Culligan, an aquatic supervisor at the New York
Department of Environmental Conservation.
"You can't get (sick) through a cut or a bite of an
animal. You have to consume the toxin," he said.
"And don't be tempted to eat a fish you find on the
Although Environment Canada says it's still OK to
swim in the lake, the carcasses are a definite eyesore.
"It's gross," said Phil Ryan, manager of the Port
Dover Ministry of Natural Resources fisheries station.
"It can certainly be ugly."
Lake Erie also suffers from anoxia - or a lack of
oxygen - as well as huge algae blooms, which worsen
the aesthetics of the area altogether.
But despite the severity of the suspected botulism
problem, scientists say they can only monitor the situation.
"We feel helpless," Ryan said. "There really isn't
anything we can do."
In the meantime, scientists continue to research the
area and urge people to report any sightings of excessive
numbers of dead fish or birds.
"Our job is to provide information and advice," Ryan
said. "And that's as much as we can do."