A U.S. engineering firm has eradicated an infestation of zebra mussels from a quarry in Virginia in what is believed to be the first extermination of the invasive species in the wild.
Aquatic Science L.P., of Orchard Park, N.Y., pumped thousands of gallons of potassium chloride solution into the quarry over a three-week period beginning in January.
The salt solution doesn't pose a threat to humans or the environment, and the water quality in the quarry and nearby wells will be monitored for the next two years, said Ray Fernald of the Virginia Department of Game and Inland Fisheries.
The eradication process cost about $365,000 US, said Fernald, an expert on zebra mussels.
"I'm not aware of any other successful eradication," said Hugh MacIsaac of the Great Lakes Institute for Environmental Research at the University of Windsor.
"That's quite impressive," he told the Associated Press.
Mussels consume fish food
Zebra mussels, small black-and-white molluscs, are native to eastern Europe. They were discovered in the Great Lakes in 1988.
Biologists believe the mussels arrived in North America in the ballast water of trans-Atlantic ships sailing up the St. Lawrence Seaway.
The mussels consume large amounts of plankton – the same food many native fish species eat – reproduce quickly and have no natural predators in North America. They grow in colonies that can clog industrial pipes leading into lakes.
The technique used in the Virginia quarry could be used in small lakes, but would be too expensive to implement in any of the Great Lakes, says Phil Moy, an invasive-species expert at the University of Wisconsin.