AP NEWS

New book details ‘killer algae’ victory

August 1, 2016

Ten years later, the local victory over killer algae remains fresh in the mind of Eric Noel Muñoz, a former Carlsbad senior planner.

“People don’t realize how close our lagoon came to being lost,” Muñoz said this week, at a celebration of the release of his new book “Caulerpa Conquest.”

Divers first discovered the bright green Caulerpa taxifolia in the Agua Hedionda Lagoon in the summer of 2000, where it may have grown from a few strands left by someone who dumped the contents of an aquarium into a nearby storm drain. While technically an algae, Caulerpa looks like seaweed and is often called seaweed.

Caulerpa is a “mutant genetic clone” of a species native to the Indian Ocean developed because it is hardy and thrives in aquariums, Muñoz said. Small pieces can break off and grow new plants, allowing it to spread easily from contact with boats or fishing lines and nets. In parts of the world, including the Mediterranean Sea, it covers acres of the ocean floor.

Like many invasive plants, the long-term effects are unknown and subject to debate. Some experts say Caulerpa spreads like a living Astroturf, smothering the native marine life, while others minimize its impact. In Carlsbad, there was a genuine danger that the algae would clog the lagoon and spread out into the ocean to infest other lagoons up and down the Southern California coast.

Muñoz’s book details how Carlsbad worked with international experts and various agencies including the California Department of Fish and Game (now Fish and Wildlife), the Regional Water Quality Control Board, the National Marine Fisheries Service and others. The joint effort was led by owners of the Encina power plant, which dredges and controls the lagoon so that seawater can cool its turbines.

The cooperation and quick action prevented the invasive plant from overtaking and probably closing the only San Diego County lagoon open to recreational watercraft. Agua Hedionda Lagoon also is home to a YMCA aquatic park, the Hubb-SeaWorld fish hatchery, a private aquafarm, the desalination plant commissioned last year, power boating, kayaking, stand-up paddleboarding and more.

“There are very few success stories when it comes to invasive species,” Muñoz said.

An initial survey in the summer of 2000 showed the invasive seaweed covered more than 11,500 square feet in the Carlsbad lagoon. A team formed to eradicate the plant immediately created a plan to cover the infestations with black plastic tarps, held down by sandbags, and to pump chlorine beneath the tarps to kill the plant.

Their plan worked. By the fall of 2001, a survey showed the Caulerpa had spread to only 362 additional square feet. The last new infestation was found in the summer of 2002, and was only 4.3 square feet. Authorities waited years to be sure it was gone, and in July 2006 declared victory.

As Muñoz describes in the book, the work was not easy and the outcome was not certain. Divers had to examine every square foot of the murky lagoon bottom multiple times, in some areas swimming shoulder-to-shoulder to search. Multiple permits were required from various agencies, and at times parts of the lagoon were closed to fishing and boats.

The total cost of the Carlsbad effort was estimated at $4 million, most of which came from state and federal grants.

Muñoz said he saved copies of all significant paperwork, publicity and news stories about the effort, always with the idea of a book. He worked on it off and on for several years.

“I always had a good outline,” he said. “I knew that would save me. I had bullet points, and then I fleshed it out.”

He likes to say that Caulerpa not only invaded the lagoon, it invaded him.

“It invaded my heart, my thoughts, my brain, and my curiosity,” Muñoz said. “And it challenged me to understand it, and to explain it to the widest audience possible.”

Muñoz was on the Carlsbad city planning staff for almost 18 years before he left in 2006 to join a private Carlsbad consulting firm, Hofman Planning, where he still works. He also is a past president of the Agua Hedionda Lagoon Foundation board of directors, and serves on the board of the California Surf Museum.

The paperback version of “Caulerpa Conquest” is available for $18 on amazon.com and in bookstores. An electronic version for Kindle is $6.99.

philip.diehl@sduniontribune.com