Anti-fouling boat paints are widely known as a significant source of copper. These paints are designed to leach copper into the water in order to reduce fouling on boat bottoms with barnacles and algae.
Unfortunately, copper and other metals are toxic to fish and other aquatic species. Numerous studies have confirmed boat bottom paint is harmful to the environment, and local studies identify boat bottom paint as the primary source of copper in Newport Bay.
Copper leaching needs to be reduced to protect marine life in the bay, starting with our Upper Newport Bay Marine Protected Area.
What is going on?
For three years, Coastkeeper ran the Newport Bay Copper Reduction Project in partnership with the City of Newport. The project promoted voluntary conversion of boats from copper to non-biocide bottom paints. The program was unsuccessful, with only ten boats converted.
Since then, Coastkeeper has been closely involved with the formation of a copper total maximum daily load (TMDL) for Newport Bay. After years of delays caused by those in opposition, in December 2022, the Santa Ana Regional Water Quality Control Board voted to adopt a TMDL, with the California State Water Resources Control Board approving the TMDL in August 2025. Click here to watch Coastkeeper’s Ray Hiemstra testify in support of the regulation. Next, the proposed TMDL heads to the California Office of Administrative Law, then the U.S. Environmental Protection Agency. Coastkeeper will be ready to defend it at every step.
Creating a better standard is just the beginning. Without educating boaters on copper paint alternatives and proper boat maintenance, the new regulatory limit will be difficult to actualize.
Click here to learn more about our copper reduction efforts.
