General Contact Number: (530) 621-5567

River Management

Invasive Species AlertImage of a Mussel
Don’t Move a Mussel!
Prevent the transport of nuisance species; Clean all recreational equipment  

There is a new invasive species in California. The zebra and quagga mussels, originally from Ukraine, landed in the Great Lakes in the 1980s and have spread steadily throughout the Midwest and Mississippi River. The mussels have explosive reproductive rates and can quickly carpet the bottom of lakes and slow-moving rivers, disrupting the food chain (as filter feeders they deplete the phytoplankton from the water) and clog water works. In recent years the mussels have invaded Lake Mead and the lower Colorado River. They have moved through the Metropolitan Water District’s Colorado Aquaduct and now have infested about a dozen reservoirs in Southern California. The California Department of Fish and Game is responsible for stemming the tide and sequestering the mussels in Southern California.

While the most common threat is mussels “hitch-hiking” on the hulls and in bilge water of trailered boats, there is also a threat they can be transported by whitewater craft that Image of a Mussel in handmove from river to river. The adult mussels can attach to the bottom of boats or in mud attached to the boat.More problematic to whitewater boating is larval mussels (called veligers), tiny organisms that drift down rivers and can live easily in splash water inside the raft/kayak. The most sure-fire way to avoid distributing them is to make sure rafts and kayaks are clean (mud free) and dry from river to river. Adults die within about a week when out of the water and veligers can be eliminated by simply draining the boat of residual water. Even though it's not a serious problem right now within Northern California, it’s a good idea to get in the habit of a clean and dry raft/kayak between put-ins on different rivers.

More information on this issue can be found at the following websites:

California Dept. of Fish and Game - Invasive Species Program

100 Meridian Initiative - The 100th Meridian Initiative is a cooperative effort between local, state, provincial, regional and federal agencies to prevent the westward spread of zebra/quagga mussels and other aquatic nuisance species in North America. Image of a Mussel cluster

Don't Move a Mussel Flyer