California is already one of America’s agricultural powerhouses. Now, a major new proposal could extend that farming identity miles into the Pacific.
State coastal officials voted Wednesday to let plans advance for what would become the largest kelp farm in the United States, located 6 miles (10 kilometers) off the Southern California coast, as the Trump administration pushes to expand aquaculture in the Pacific Ocean.
Ocean Rainforest, a company based in the Faroe Islands in Northern Europe, wants to cultivate giant kelp across about 3 square miles (7.8 square kilometers) of federal waters. The seaweed would be used to create products aimed at improving soil and plant health for California crops, including avocado farms and strawberry fields. But some environmental advocates worry the lines used to grow kelp could entangle whales, while additional vessel traffic could disturb a stretch of ocean that has remained largely wild.
The company says it would scale up the operation gradually over 10 years. At full capacity, the farm could produce up to 6,000 tons of kelp, helping grow a U.S. seaweed industry that remains far behind Asia’s despite the nation’s long coastlines. Ocean Rainforest plans to harvest the kelp offshore and process it in Ventura, a port city about 60 miles (97 kilometers) northwest of Los Angeles.
“Let’s start in our backyard,” Douglas Bush, Ocean Rainforest’s director of California operations, said in a recent interview. “Let’s grow the seaweed here, let’s process here in California, let’s use it in California farms.”
Kelp farm proposal reflects broader aquaculture push
The Ventura County kelp project is moving forward as federal officials promote commercial aquaculture. Last year, the National Oceanic and Atmospheric Administration identified 13 areas totaling 33 square miles (85 square kilometers) off California and Texas for aquaculture development. The effort stems from a 2020 initiative to strengthen the U.S. seafood industry.
Interest in seaweed is also rising as companies find uses for it in everything from restaurant menus to pet food. Dozens of farms are already growing different varieties in New England, the Pacific Northwest and Alaska. A 2023 World Bank report estimated that seaweed markets could expand by an additional $11.8 billion by 2030.
Some environmental groups backed the California project, noting seaweed can help absorb carbon dioxide from warming ocean waters and restore habitat while feeding off ocean nutrients.
Environmentalists raise questions
But some raised questions about the impact of hundreds of boat trips a year to maintain and harvest the seaweed and the potential for whales migrating or feeding in the area to get tangled in lines stretching up from the sea floor, or tethered to buoys, to grow the kelp. Ocean Rainforest said no whales got tangled in taut lines during a two-year demo project.
“This is our blue Serengeti. This is a very wild place,” said Geoff Shester, director of fishery innovation at the ocean conservation group Oceana. “It’s like you might as well put a bunch of industrial data centers in Yosemite National Park.”
Cassidy Teufel, deputy director at the coastal commission, said during a review of the project that seaweed farms use taut, rigid lines, not the loose fishing lines that are a leading cause of whale entanglements. The farm will be located further offshore where there’s a lower density of marine mammals, Teufel said.
It is possible the project will draw fish, and sportfishing will be permitted in the area, Teufel said. Some commercial fishing will be displaced, and Ocean Rainforest and fishermen said they are working on an industry support fund.
Under U.S. law, California officials have a say over projects built on federal properties that will affect the state’s coast. The California Coastal Commission voted unanimously to let the kelp farm move forward with conditions including a phased approach. Ocean Rainforest will initially build in a smaller area and face periodic reviews by the U.S. Army Corps of Engineers and the commission’s director before expanding to full capacity.
With the decision, Ocean Rainforest said it has the major approvals needed for the project. Construction could begin in 2027.
The region around Ventura is known for growing strawberries, avocados and other crops.
Ted Travers, chief operating officer of the avocado farm Simpatica, said he was eager to see kelp-based products for agriculture developed on the West Coast. He said in a letter to the commission that all the kelp currently used for agricultural purposes comes from the Atlantic Ocean, “which is financially and environmentally impractical.”
Ventura and port officials welcomed the project as a way to bring new industry and jobs to the city of 100,000 people.
