U.S. biologist warns great lakes threatened by weed
Date: 18-Feb-00
Country: CANADA
"I think it's just a symptom of a wider problem. We have over time seen
more of these non-native species (of aquatic weeds) coming into our
water resources and there is very little control over it," biologist
John Madsen told Reuters, after addressing an aquatic
nuisance conference in Toronto.
Madsen's research suggests the hydrilla, a weed that already plagues
waterways in Florida and Connecticut, could spark navigation, flood
control and hydro-electric problems in the highly travelled and
commercially important five Great Lakes.
Exactly when the hydrilla will begin invading the Great Lakes region is
not known, but the water system's conditions support the weed's growth,
Madsen told Reuters.
"I don't envisage the lakes will be wall-to-wall hydrilla, but it can
displace native plants and block the entrance and exits to harbours, for
example," Madsen said.
Researchers blame homeowners who plant water gardens, aquarium owners
flushing tank contents into sewers, and fishermen who fail to clean
their boats before leaving a waterway.
Madsen said hydrilla's thick mat starves native aquatic plants of
sunlight and alters fish habitats.
Because it can cause damage to canal banks and structures, real estate,
tourism and fisheries sectors can be hit hard.
Hydrilla infestations affect other areas of the world including parts of
South America, Europe, Australia and New Zealand.
