Californians have benefited from the introduction to this state of various fish, plants and other species necessary for food or other human pursuits; however, there are many other introduced species that can wreak havoc on the state’s environment and economy. Those species that cause harm and spread quickly from their point of introduction are often called “invasive.”

For these species, a single individual may produce thousands of seeds, masses of larvae or reproduce from nothing bigger than bits of stems, roots or leaves. Those that live in or near the water – aquatic invasive species – can be easily dispersed to distant water bodies or new ecosystems by currents, tides, river flows, streams, floods and other water flows.

This plan proposes management actions for addressing aquatic invasive species (AIS) threats to the State of California. It focuses on the non-native algae, crabs, clams, fish, plants and other species that continue to invade California’s creeks, wetlands, rivers, bays and coastal waters.

State surveys indicate that at least 607 species of aquatic invaders can be found in California’s estuarine waters. These invaders cause major impacts: disrupting agriculture, shipping, water delivery, recreational and commercial fishing; undermining levees, docks and environmental restoration activities; impeding navigation and enjoyment of the state’s waterways; and damaging native habitats and the species that depend on them. As the ease of transporting organisms across the Americas and around the globe has increased, so has the rate of AIS introductions.

RELATED DOCUMENT: California Aquatic Invasive Species Management Plan – Appendices