Only a few years after its first appearance in Ireland, the zebra mussel has thoroughly saturated the State's waterways. At least one trillion can now be found in Lough Ree alone.
The pests attach themselves to hulls in such numbers they can sink a ship and they are steadily making their way up the Shannon, according to environmental ecologist Ms Frances Lucy. Addressing students and environmentalists last night at the Sligo Institute of Technology, in one of a series of lectures as part of Science Week Ireland, she said boat-owners must scrub their hulls and clean their bait buckets methodically if there was to be any chance of stopping the zebra mussel from fouling other lakes.
The small striped molluscs, which grow up to 25 mm, clog industrial intake pipes, drains, screens, power plants and waterworks. In America's Great Lakes, the mussels have shut down power plants and cost companies more than $5 billion since they were found there in the 1980s.
They also create intense environmental problems for the area, Ms Lucy said. "They have almost wiped out the Irish swan mussels local to these waters and their sharp shells regularly cut bathers. And as for zebra mussels making the water cleaner, they've only transferred all the algae to the lake floors. It's an illusion."
The zebra mussel originated in the Black and Caspian seas, but have spread rapidly by stowing away on the ballasts of commercial ships. With their vast reproductive capabilities, parts of Lough Key were fully covered with the mussels, Ms Lucy said.
This year she will be starting a three-year Environmental Protection Agency-funded project on Lough Key to determine whether reducing the phosphorous in the water would stop the spread.