California wins first battle. Will bivalves win war?

Freshwater Quagga mussels are small, each about the size of a fingernail, and can filter water like nobody’s business. But state and federal officials worry that it is only a matter of time before these invaders make another go for California, and cause a huge amount of economic damage and ecological changes to state waterways.

The little Quagga, a bivalve mollusk indigenous to Ukraine, first was spotted in America at Lake Erie in 1989. Scores of them soon populated the Great Lakes and then spread out across the country, like their cousin the Zebra mussel a decade earlier.

And they caused a lot of headaches along the way. Now they’re causing headaches for California’s Fish and Game employees.

Great Lake states and companies pay billions to keep the mussels from sticking to motors, fish screens, piers and pylons, said Troy Swauger, a spokesman for the state Department of Fish and Game. They also clog pipes used by power plants, and deprive some native species of fish of plankton–their food supply. Quagga mussels are edible, but they are impractical to eat because of their small size. “There is nothing good about them.