Common Nuisance Species

Non-native aquatic species—plants, fish, and animals—are invading California’s coastal and inland waters. Introducing non-native species into California waters not only upsets the balance of the ecosystem, thereby harming the environment, but it is also against the law. These pests can increase dramatically under the right conditions, displacing native species, clogging waterways, and impacting navigation and recreation. Once introduced, they are nearly impossible to eliminate. Aquatic nuisance species, such as zebra mussels, quagga mussels, Egeria densa, water hyacinth, and hydrilla, can be accidentally transported by recreational boaters when caught in propellers, intakes or attached to hulls. Controlling these species is a multi-million dollar problem in California.