Undersea Activism

Restoring the Kelp Forests of Northern California

by Lisa Ludwigsen

From shore they glisten as massively dense, slowly undulating, impenetrable masses of shiny ocean plants. Below the surface, kelp forests host complex ecosystems of plant life, marine mammals, fish, birds, and invertebrates. These vast underwater forests have existed for thousands of years, providing healthy sources of food, shelter, materials, and cultural practices. But it is safe to say that we don’t yet fully understand all the ways they contribute to the planet’s wellbeing.

What we do understand is that over 95% of the bull kelp forests along Northern California’s coast have disappeared since 2014, when a sudden marine water heat wave caused upheaval in the entire ecosystem of the coastal Pacific Ocean. The warm water coincided with a mysterious sea star wasting syndrome, killing the sea stars and allowing their main food source, purple sea urchins, to explode in population. Those urchins, in turn, voraciously fed on the kelp, eradicating most of the kelp forests in an astoundingly short time. As the kelp forests disappeared, so did the plant and animal life dependent on that habitat. The scenario is alarming, yes, but organized restoration efforts are showing real promise.

Bull kelp is a type of seaweed which requires the typical cold water of the Pacific coast, thriving from Alaska to California. With an annual growing cycle and impressive growth rates of up to a foot per day, the kelp anchors via bulbous holdfasts in relatively shallow, rocky areas with moderate wave action. If you live near or visit the coasts of Northern California, you have likely seen them. Stalks of bull kelp—the stipe—can grow up to 65 feet in length and are held up by the spherical float, an air-filled buoyant ball supporting many flat blades that create a layer on or near the surface. These plants really do create underwater forests, providing food and shelter for a wide variety of animals. At year’s end, the kelp dies, and new plants are produced for the following year. The dead kelp masses continue to provide nourishment as they float on the surface.

The Surfrider Foundation is an international nonprofit environmental organization with over 100 chapters. The Mendocino County chapter has provided volunteers since 2002 to help keep beaches and water clean and accessible. Increasingly, Mendocino County Surfrider Foundation has been working to protect our coast from offshore oil and gas drilling, and to curtail the expansion of underwater sonar and weapons testing by the U.S. Navy. Surfrider is also assisting with kelp restoration through a broader based collective called KELPRR (Kelp Ecosystem Landscape Partnership for Research on Resilience), a coalition of marine scientists, divers, tribes, nonprofits, fish catchers, and others.

One crucial step to stop further decimation of kelp is the removal of purple sea urchins from the ocean floor. “We are seeing positive outcomes from urchin management efforts on our coast,” says Nicole Paisley Martensen, chairperson of the Surfrider Foundation, Mendocino County Chapter. “Over the past two years, the Noyo Center for Marine Science coordinated urchin removal efforts with commercial divers under guidance from California Department of Fish and Wildlife, removing over two million urchins from kelp ‘oasis’ zones at Noyo Bay, Caspar Cove, and Albion Cove,” she explains. The efforts in these survey zones have been surprisingly effective and have brought additional attention from policy makers and others.

In July, 2021, Congressman Jared Huffman introduced the KELP Act—Keeping Ecosystems Living and Productive Act, HR4458. Funded by NOAA, it proposes to provide $50 million annually from 2022 through 2026 for the conservation, restoration, and/or management of natural kelp forest ecosystems. “Working with Congressman Huffman and his team on writing this proposed legislation was such an honor,” says Nicole. “It felt like this is the leap that needs to be taken to jump from grassroots triage to federally-funded crisis prevention.” As of this printing, Congress has not yet voted to enact the KELP Act.

Alarmed by the state of the kelp forests, a group of concerned Northern California-based artists and activists have engaged with scientists working directly on kelp recovery to create the project titled Above/Below. The artists come from Santa Cruz to Mendocino and work in a range of media including film, multi-media, watercolor, large silk cyanotypes, and kelp itself. The science component includes representatives from The Nature Conservancy, the Estuary & Ocean Science Center at San Francisco State, U.C. Berkeley Herbarium, Noyo Center for Marine Science, and the Kelp Recovery Program at the Greater Farallones Association.

To launch the three-year awareness building campaign, Above/Below held a gathering of approximately 100 stakeholders in Sausalito in October 2021, with presentations by the science community and exhibits of work from the involved artists. Nibbles were sourced from fish that interact with kelp forests, including rockfish, salmon roe, anchovies, and, of course, Uni Onigiri—sea urchins. Oysters were provided by Hog Island, located on Tomales Bay in Marshall, California.

The event was organized in part by Marianna Leuschel, a Sausalito woman who became curious about the role of kelp while walking the beaches around Point Arena. It wasn’t long before she learned about the dire situation the kelp forests face, and she felt compelled to help others understand as well. With a background in communications and a network of inspired and creative friends, Marianna spearheaded Above/Below to use food, art, and science to “tell a compelling story of the kelp forests on the North Coast, and inspire people to get involved in supporting the protection and restoration of these endangered forests of the ocean.” Appealing to the public on multiple levels is essential since, as Marianna points out, it’s “an issue that is challenging for many of us to experience—because kelp forests live in a realm not visible to most—but one that touches all of our lives through our local foods, ecology, culture, and climate.”

A particularly illuminating speaker at the event was Rietta Hohman, coordinator for the Kelp Recovery Program at the Greater Farallones Association. The association is addressing the kelp crisis with a three-pronged approach: restoration, research, and partnerships. The restoration involves urchin removal in the zones near the shore where kelp usually thrives, as well as growing kelp in labs and then planting them out in the ocean once they are hardy enough to survive. Research includes monitoring the kelp zones off the coast of Sonoma and Mendocino to keep an eye on which areas need the most attention. And partnerships are enhanced through KELPRR, which brings together concerned stakeholders and is open to anyone who wants to participate.

It’s encouraging to hear about Hohman’s work, and indeed about the efforts of all the people and organizations who care about the kelp forests: policymakers, researchers, surfers, scientists, artists, and just concerned citizens like Marianna who want to make a difference. If 95% of the dry land forests in Northern California had disappeared, there would understandably be an urgent outcry for immediate and intense corrective action. With our underwater kelp forests in equal peril, it’s imperative that we pursue all options available for ceasing and reversing their devestation. Fortunately, the abundance of skills, knowledge, concern, and creativity the different participants bring to this issue have put us on a path where that just might be possible.


How can you help?

  • Know where your food comes from—eat seafood from regenerative sources. Oyster, clams, mussels, and seaweed improve waterways.

  • Ask your representatives to support the KELP Act.

  • Join the KELPRR email list at

  • farallones.org.

  • Visit the Noyo Center for Marine Science in Fort Bragg.

  • Join Surfriders at

  • mendocino.surfrider.org.

  • Visit the ocean! Take your children and experience the wonder of the ocean and tide pools.

Find out more about Mendocino County’s collaborative efforts to eradicate purple seas urchins via eco-culinary activism in the Word of Mouth Summer 2020 issue.


Photos: Van Damme State Beach by Krzysztof Ziarnek, Kenraiz, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons. Art event photos by Torrey Douglass. Bull kelp photo by Keith Johnson.

Lisa Ludwigsen is a writer and marketer working with food, farms, and family small businesses throughout Northern California. She has worked in organic agriculture, natural foods, and environmental education for over 20 years.