From the Star Tribune in the USA:
Invasive quagga mussels found in Duluth harbor
This exotic mussel has been spreading through the Great Lakes, competing with other species and fish for food — and winning.
By Tom Meersman, Star Tribune
Last update: January 10, 2007
Aquatic critters in the Duluth-Superior harbor may face some crowding in the near future: Federal officials confirmed Wednesday that they have found an invasive species called the quagga mussel for the first time in Lake Superior.
The prolific mussel has disrupted the ecosystem of other waters by competing with native species and small fish for food — and winning.
The quagga mussel resembles another invader, the zebra mussel, which has spread rapidly in North America over the past two decades and cost billions of dollars.
Quagga mussels were named in parallel to the quagga, a zebra species with less stripes than other species.