A species never before seen in North America was found in California

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...