Flexing our muscles against alien mussels

A pair of invasive species are threatening to `mussel' their way into California lakes and streams, potentially devastating freshwater ecosystems and bringing great ecological and monetary costs.

The quagga and zebra mussels (Dreissena rostriformis and D. polymorpha), diminutive but extremely prolific European mollusks, were accidentally introduced into the Great Lakes in the 1980s and soon became widely established in eastern waterways, where they have clogged intake pipes, destroyed outboard and inboard motors, turned mooring lines into razor blades, and monopolized so many nutrients that fish and other forms of aquatic life starve. Direct clean-up and maintenance costs imposed on water companies and others top $100 million annually, and the environmental devastation and recreational losses are immense.

An intensive effort to arrest this invasion at the Mississippi River succeeded for a while, but in January 2007, quagga mussels were found in Lake Mead, and then elsewhere in the Colorado River drainage and several unconnected reservoirs in San Diego County. More recently, zebra mussels have been confirmed in San Justo Reservoir east of Monterey, with recreational boaters the most probable vector of contamination. Once a mussel invasion is established, it is virtually impossible to eliminate. Just the attempt would require heavy doses of lethal chemicals - not an option when drinking water is involved, even if it were acceptable ecologically.

In October California passed AB 1683, empowering the Department of Fish and Game (DFG) to inspect boats, other vehicles (e.g. trailers and seaplanes), and marinas; to impose mandatory decontamination; and to quarantine infested bodies of water; but these new powers were not accompanied by increased funding.

The Sierra Club played an important role in the passage of AB 1683 and regards mussel containment as a serious concern, but state budgetary constraints make it highly unlikely that DFG will get the funding to exercise its new powers or to set up inspection stations at the state border. There probably won't even be money for a comprehensive informational campaign.

Our individual efforts can help. Boaters, in particular, should learn to inspect and decontaminate their vessels, trailers, live wells, buckets, and anything else capable of transporting mussels or larvae - every time they move from one body of water to another. All of us can help disseminate information about the mussel hazard and appropriate preventive practices.

For details on these procedures, and for more information about invasive mussels in general, visit: www.dfg.ca.gov/quaggamussel

Victoria Brandon