A Tiny Threat Could have Big Impacts on California’s Drinking Water

At first glance, the small golden mussel doesn’t look like much of a threat. When clustered on a pier or the bottom of a buoy, the brownish spheres wouldn’t draw much attention, especially as they look like several of California’s native mussel species.

But the tiny mollusks, which can reach up to 2 inches in length, are a big concern: The California Department of Fish and Wildlife, California State Parks, and the California Department of Water Resources just announced the invasive species has been found in North America for the first time in the Port of Stockton in the Sacramento-San Joaquin Delta — and they’re already in at least one California reservoir.