Thompson-sponsored bill would boost fight against invasive quagga mussels

A type of mussel that poses a threat to lakes and water supply systems would officially be added to the national list of invasive species under legislation sponsored by Mike Thompson, D-St. Helena.

Thompson on Thursday announced his introduction of the bipartisan bill to add the quagga mussel to the listing.

Since their invasion in the 1980s in the Great Lakes, quagga mussels and their close relative zebra mussels have been responsible for more than $5 billion in prevention and control costs - more than any other aquatic species, according to Thompson's bill.

While zebra mussels are on the invasive species list, quagga mussels are not.

The listing gives federal agencies greater ability to prevent the spread of the species, which clogs pipes and other infrastructure.

"It would fix a loophole. It further enforces the penalties for transportation of these mussels," Brad Sherwood, a spokesman for the Sonoma County Water Agency, said of Thompson's bill.

The most common way the mussels spread is by "hitchhiking" on recreational boats.

In Thompson's Congressional district, Clear Lake, Lake Sonoma and Lake Berryessa are all rated at the highest possible risk of quagga infestation, although the mussels have not been introduced so far.

While the mussels have caused problems in reservoirs and lakes in Southern California, they have not been found north of San Benito County.

A consortium including Sonoma, Mendocino and Humboldt counties is planning to begin mandatory boat inspections next year.