A tiny invasive species is a big threat to CA water

CalMatters via email

When thimble-sized mussels were first detected last year in the Sacramento-San Joaquin Delta, biologists quickly rang the alarm over how severely this invasive species could threaten the state’s water supply systems.

Now, nine months after the mollusks’ appearance near Stockton, officials are in a race to rein in golden mussels as their larvae spread through the state’s network of pumps, pipes and canals, reports CalMatters’ Rachel Becker.

Native to China and Southeast Asia, these freshwater mussels can attach themselves to underwater surfaces and form “reefs” that can grow as fast as 150 miles a year. The mollusks have already infiltrated California’s two major water systems that send Delta water south to 30 million people and millions of acres of farmland.

To curb their spread, some water managers are requiring inspections that include quarantining and decontaminating boats before they can enter certain lakes and reservoirs. California’s fish and wildlife agency also has a handful of dogs trained to detect the mollusk.

But the wildlife department is understaffed, and the recently passed state budget includes no funding to combat the mussels. Oversight is also patchy, leaving many lakes with no protection. The federally-managed Shasta Lake, for example, is the biggest reservoir in the state and frequented by boaters — but it does not have a mandatory inspection program.

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