The Invasive Species Spreading Across California That Could Ruin Tourists' Lake Vacations

Travelers hoping for a relaxing lake vacation likely already know about invasive zebra mussels and quagga mussels that have overrun many popular lakeside destinations. Lake Superior's uncrowded sandy beaches could become even less crowded if the mussels filter plankton out of the water, potentially leading to algae blooms overtaking the surface. Unfortunately, California faces a similar threat from another invasive species: Golden mussels. The mollusks have been detected in the Sacramento–San Joaquin Delta, and they have already spread to two Southern California lakes near Los Angeles: Silverwood Lake and Pyramid Lake. The likelihood of the mussels spreading from Silverwood Lake to connected Lake Perris is high, and the spread will not stop there.

Golden mussels are a type of freshwater mollusk indigenous to Asia. The reason these mussels are so dangerous is because of how rapidly they spread. Their small size allows them to clog water pipes and boat engines, which are incredibly costly to repair. Even worse, once the mussels attach themselves to a rock or the underside of a boat, they are almost impossible to pry off. Because the mussels are filter feeders, they accumulate nutrients that help algae grow in large blooms. These blooms are not safe for swimmers, boaters, or water supplies. Because the Sacramento-San Joaquin Delta is a major supplier of fresh water to California, the mussels threaten to jeopardize the supply for nearly two-thirds of the state's population.

The invasive mussels are resilient because they can cling to objects and survive for up to a week outside the water. Keep in mind that this is not limited to boats. Golden mussels will cling to rocks, shells, boat hulls, beach toys, paddleboards, kayaks, floaties, life jackets, fishing gear, and water shoes. They can spread when lake vacationers take their boats, beach equipment, and swimming gear from an infested lake to a non-infested lake. Just one mussel is enough to start a full-scale invasion, so one person can cause widespread damage if they are not careful.

On May 30, California's beloved Lake Tahoe almost fell victim to this fate. A 46-foot boat carrying golden mussels was nearly launched into the water. Had that happened, Lake Tahoe's retreat on the Nevada-California border could have begun its transformation from a crystal blue lake into a green algae-filled pool. Fortunately, the Alpine Meadows Watercraft Inspection Station caught the infestation during a mandatory watercraft inspection. The Tahoe Regional Planning Agency requires all watercraft to undergo an inspection prior to launch. Because golden mussels are nearly impossible to remove once they spread, the only way to stop them is through vigilant prevention. Anyone who wants to launch a vessel that has already been in mussel-infested waters should get an inspection immediately. Otherwise, California's lakeside areas may still have secret trails and sun-warmed rocks, but they will lose their sparkling blue water and water recreation.