Discuss Health of Great Lakes
The Globe and Mail
While invasive species such as the zebra mussel and
urban sprawl are harming the Great Lakes ecosystem, scientists
say drinking water quality has improved and the level
of contaminants in fish has decreased.
Experts from both Canada and the U.S. are gathered in
Cleveland, Ohio this week to discuss the health of the
lakes system, which is monitored under the Great Lakes
Water Quality Agreement between Canada and the United
Under the agreement, the two countries are required to
accurately monitor and report on the health of the Great
Water quality from the Great Lakes, as well as the surrounding
surface, ground and river water was assessed and found
to have improved, the experts said.
Harvey Shear, regional science advisor for Environment
Canada, said that the level of contaminants in Lake Ontario
is slightly higher than the rest of the Great Lakes because
Lake Ontario is at the end of the lakes chain.
"But the trends there are still in a favourable direction,"
Mr. Shear said in a conference call from Cleveland.
The agreement between the two countries has helped them
make strides in reducing contamination in the Great Lakes,
said John Mills, regional director general for Environment
Of 17 designated "Canadian hotspots" of contamination
in the Great Lakes, improvements have been made to all
of them and two have been taken off the list, Mr. Mills
Canada and the United States have also co-operated to
improve the state of the Niagara River, which was on the
receiving end of pollutants flowing into it from the United
Over a 10-year period, the two countries have reduced
the amounts of contaminants in the river by 50 per cent.
"It's a long ways from zero, but we have made some significant
improvements there," Mr. Mills said.
Contaminant levels are also decreasing in the outer
layers of fish tissue found in species in the Great Lakes,
the scientists said.
But other issues such as urban sprawl which causes natural
habitat loss, and invasive species, are still a cause
for concern, the scientists said.
Invasive species such as the zebra mussel are ruining
a delicate ecological balance in the Lakes ecosystem,
Mr. Shear said.
"They essentially just disrupt the whole food chain,"
he said, explaining that they cause problems in the biological
community by feeding on items which other wildlife need.