Invasive Species Surge as a Result of Winter/ Spring Storms


Facilitating wide-ranging efforts to help California communities recover following the severe winter and spring storms is a priority for the California Governor’s Office of Emergency Services (Cal OES). Cal OES’s Environmental-Historic Preservation (EHP) unit reminds affected residents of the possible surge of invasive species due to storm-related flooding. Californians can report sightings of invasive species online. Cal OES encourages all residents to practice conservation efforts to protect threatened and endangered species of California.


Native to South America, the semi-aquatic rodent was originally brought to the US in 1889 for its fur. When the market collapsed, thousands of Nutria escaped or were released into the wild by ranchers. The United States recognizes Nutria as an invasive species in 20 states and, most recently, in California. While they devour weeds and overabundant vegetation, their burrowing activities frequently cause water-retention or flood control levees to breach, weaken structural foundations and erode riverbanks. Because they consume an immense amount of vegetation, they also cause damage to California’s native plant community and soil structure.

American Bullfrogs

Bullfrogs were intentionally introduced to the California ecosystem during the gold rush and preceding years by frog farming operations and released by pet owners. American Bullfrogs are a highly invasive species, as they have voracious appetites and will eat anything they can fit into their mouths including birds, bats, lizards, rodents, frogs and more. Adult bullfrogs can weigh over two pounds and can measure over eight inches in length. They also carry a fatal fungus that can cause the decline of native amphibian populations, like the endangered California Red Legged Frog.

Zebra and Quagga Mussels

As summer approaches, EHP reminds boaters to inspect, clean, drain and dry the hulls and ballast of boats to prevent Zebra and Quagga mussels from entering any bodies of water. They pose a serious threat to California’s waterways and fisheries. The spread of these freshwater mussels is currently posing a national security threat, as the they can cause damage to water delivery systems, hydroelectric facilities, agriculture and more. Federal and state agencies have been working together to prevent, contain and control the Quagga and Zebra mussel population since their discovery in Lake Mead in 2007.

Giant Reed

Originally from Eastern Asia, the Giant Reed was introduced to California during the 1820’s to provide roofing materials and erosion control in the Los Angeles Basin area. The Giant Reed is a fast-growing plant and is exceptionally resilient to a variety of environmental conditions. This plant readily breaks apart during floods, sweeps downstream and reestablishes in a different area. Since this invasive plant can grow fast and large, and absorbs an extremely large amount of water, it continues to pose issues to a drought at-risk state.


Additional Resources:

More information on invasive species

List of California Protected Animal Species

Listed of Protected Plant Species



Cal OES’ Environmental-Historic Preservation (EHP) unit provides subject matter expertise with regard to state and federal environmental and historic laws/regulations. The unit conducts technical reviews of pending grant awards to determine whether the proposed projects follow state and federal regulations and makes recommendations concerning methods to mitigate environmental impacts, in addition to assisting to resolve difficult and complex environmental issues.