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Sun, Aug. 09

Invasive mussels in Arizona waters

Quagga mussels have been discovered at multiple sites at Lake Pleasant in Phoenix, and state wildlife officials are requesting that boaters and other recreationists take simple steps to help prevent this Eastern European menace and other aquatic hitchhikers from spreading to other lakes.

On Dec. 17, small adult mussels were collected from a dry-docked boat that had been moored at Pleasant. A team of biologists from the Arizona Game and Fish Department also discovered mussels in the southern end of the lake from boat slips at the Lake Harbor Marina, at the Pleasant Harbor Marina boat launch and the 10-lane boat ramp courtesy dock. Those invasive mollusks have been confirmed as quagga mussels.

Quagga mussels, which have caused millions of dollars in damage in the Great Lakes region, were first discovered at Lake Mead in January of this year. Since then, they have been confirmed in lakes Mohave and Havasu and their presence has been suspected, but not confirmed, at Lake Powell. This past fall, quagga mussels were discovered in a segment of the Central Arizona Project (CAP) Canal in Scottsdale. The CAP canal originates at Lake Havasu. Water from the CAP is used to fill Lake Pleasant.

"We suspected that it was just a matter of time before quagga mussels became established in Lake Pleasant, but we hoped it wouldn't happen so soon," said Larry Riley, a fisheries biologist with the Arizona Game and Fish Department.

Riley, who is heading the Quagga Team for the state wildlife department, pointed out that a single quagga mussel can produce 30,000 to 40,000 fertilized eggs in a single breeding cycle. One adult female quagga can release up to a million eggs in a single year.

Game and Fish Department officials are asking all boaters and anglers throughout the state to help fight the continuing spread of these and other invaders by routinely taking simple precautionary steps each time they visit a waterway anywhere in the state.

Riley added that the presence of other invasive species, such as golden algae, means all boaters and other water recreationists should take simple, precautionary steps - every time they go to a lake, river or stream.

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