On Thursday, July 27, Governor Newsom signed Assembly Bill 655 into law, enacting a statewide ban on the invasive Caulerpa genus of algae. The bill was introduced by Assemblywoman Cottie Petrie-Norris (D-Irvine) with the help of Orange County Coastkeeper and California Coastkeeper Alliance.
Under AB655, Californians are prohibited from selling, possessing, importing, transporting, transferring, releasing alive in the state, or giving away without consideration all saltwater algae of the genus Caulerpa, except that in possession for bona fide scientific research.
Caulerpa Threatens Our Coastal Environment
The Caulerpa genus is popular in the aquarium trade due to its hardy nature, fast growth rate, and attractive green color. It is native to the warm, tropical waters of Florida and the Caribbean. However, it can easily adapt to and thrive in California’s colder waters.
Caulerpa has been shown to rapidly outcompete California native plants in areas it has invaded, displacing wildlife and altering the ecosystem around it. A single blade can sprout a whole new plant, making it hard to remove without constant monitoring. It also contains toxins that repel most fish outside its native range.
Past and Current Caulerpa Invasions
An established patch of Caulerpa prolifera, a species within the Caulerpa genus, was identified in Newport Bay’s China Cove in early 2021. The Southern California Caulerpa Action Team (SCCAT), a group of various agencies and stakeholders, has since been surveying for and removing C. prolifera plants throughout the Bay. SCCAT’s methods have been effective; however, limited funding has made total eradication impossible thus far.
A close cousin of C. prolifera, Caulerpa taxifolia, was discovered in California in 2000 and took almost seven years and $7 million to eradicate. At that time, it did severe damage to native eelgrass habitat.
Protecting Our Coast from Further Invasion
Illegal dumping of aquarium water is the most likely source of both the C. taxifolia invasion of the early 2000s and the current C. prolifera invasion in Newport Bay.
In 2001, California banned the transportation and sale of C. taxifolia and several other Caulerpa species. However, C. prolifera and the rest of the genus remained legal to sell and trade. The statewide ban will go into effect on January 1, 2024.