Tiny Invader Sparks Big Alarm in California Waterways

California is scrambling to contain an invasive species never before seen in North America: the golden mussel. First detected in October 2024 in the Sacramento-San Joaquin Delta, the tiny mollusk, no larger than a paperclip, has now triggered a sweeping, statewide emergency response.

State officials with the California Department of Fish and Wildlife unveiled a Golden Mussel Response Framework this week, calling the threat “urgent” and laying out a long-term strategy to prevent further spread.