May 2026
Caulerpa in Newport Harbor: Origins and Ongoing Response
By Devon Kelly
Board Member Devon Kelly
Caulerpa Prolifera is an invasive aquatic species that is not native to California. It grows quickly and spreads aggressively forming dense mats that smother native vegetation and alter the harbor’s underwater landscape.This aquatic invader was first discovered in San Diego Harbor in the early 2000s. Although it was eradicated, it reappeared within a year in Huntington Harbor, where additional efforts were made to contain and eliminate it. The species was not detected again until 2021, when Caulerpa was found in China Cove in Newport Harbor. In 2023 Caulerpa was identified near Collins Island Bridge, and in 2024, it was found again on the backside of Linda Isle.
How Caulerpa arrived in the bay is not entirely clear, but several theories exist. One possibility is that aquarium water and plants are improperly disposed of, allowing them to enter natural waterways. Another theory suggests that boat hulls and equipment can transport algae fragments from one body of water to another. Additionally, ships traveling from tropical regions may inadvertently introduce algae into local waters.
The City of Newport Beach has responded swiftly and continues to work diligently, in collaboration with multiple agencies, to remove and prevent the spread of this invasive species throughout the bay. Efforts began immediately after Caulerpa was discovered in China Cove and remain ongoing today. Regular surveys are conducted, and trained divers carefully monitor affected areas in Newport Harbor. Divers manually remove the plants using nets and dispose of them properly. This is a delicate process as even small fragments can break off, drift away and take root in new locations.
Preventing further spread of Caulerpa will require continued effort and awareness from both agencies and the community.
May Issue
More of What’s Inside
A Message from Dennis Durgan
President of the Newport Harbor Foundation
We are deeply grateful to each and every one of you—our generous donors, dedicated residents, and passionate supporters—who continue to champion the mission of the Newport Harbor Foundation. Your unwavering commitment to preserving and protecting our beloved Newport Harbor makes all of our work possible.
Why Newport Harbor Must Be Dredged
By Marshall ‘Duffy’ Duffield
On any given day, Newport Harbor tells the story of coastal life in Southern California. Early in the morning, sailors ease quietly out of their slips toward the open ocean. Paddleboarders glide across calm water. Later in the afternoon, families cruise the harbor while waterfront restaurants fill with visitors enjoying the view.
The Newport Bay Trash Interceptor
By NHF Staff
We’re excited to share some groundbreaking updates about the Newport Beach Trash Interceptor and the cutting-edge technology that’s helping us better understand and combat marine pollution. Our community’s commitment to protecting Newport Bay and the Pacific Ocean continues to drive innovation and positive environmental change.
Leveraging Resources Near and Far
By Paul Blank, Harbormaster
The Harbor Department continues to deliver on its mission to keep Newport Harbor clean, safe, and well-enjoyed. A key component of that mission is actively seeking opportunities to collaborate with partner agencies—local, state, and federal—to bring additional resources and capabilities to Newport Harbor.
The Harbor and Invasive Algae
By Devon Kelly
Caulerpa Prolifera is an invasive aquatic species that is not native to California. It grows quickly and spreads aggressively, forming dense mats that smother native vegetation and alter the harbor’s underwater landscape.
Balboa Island Ferry Electrification Update
By NHF Staff
Great news for Newport Beach and ferry lovers everywhere! The beloved Balboa Island Ferry, which has been shuttling passengers and vehicles across the harbor for over 100 years, is embarking on an exciting journey toward a cleaner, greener future. After facing potential closure due to California’s stricter emissions regulations, the ferry has secured crucial funding to electrify its entire fleet.
2026 State of the Bay Luncheon
Join Us for the Third Annual State of the Bay Luncheon on Wednesday, May 13th, at the Newport Harbor Yacht Club. Click on the link for all the details and a sign-up link
