It provides life-giving oxygen and is used in everyday consumer products like toothpaste.

Seaweed.

Also known as kelp, the fast-growing marine algae provides structure for biodiverse ocean life and has increasingly found its way into hundreds of food, pharmaceutical and cosmetic items.

Experts say it could also be a solution to climate change due to its ability to remove excess carbon dioxide from the atmosphere through photosynthesis, slowing ocean warming. 

Boats are moored in the harbor at Newport Beach, Calif., on Friday, April 5, 2025. The coastal city is a popular destination for recreational boating, especially as warmer spring weather draws more visitors to the water. CREDIT: KADE MCKENNA, Voice of OC

“Most of the kelp in Southern California has historically gone into production of things like albinate used in thickeners, but it does have major industrial importance, and it has for decades and decades,” said Matthew Bracken, a professor of ecology and evolutionary biology at the University of California, Irvine that also has studied kelp.

“We are starting to see this as a climate solution now because there are major advantages to things like kelp and other seaweeds.”

But kelp and other seaweeds are threatened by ocean warming and pollutants. A marine heatwave in the last decade wiped out more than 90% of kelp forests along the Northern California coast. 

A strain of “super kelp” first transplanted off Newport Beach in the 1970s could hold the key to preserving California’s vanishing kelp forests in its genes.

Karina Arzuyan holds a container of kelp gametophytes in a molecular biology lab inside Ray R. Irani Hall on the University of Southern California campus on Sept. 5, 2025. Credit: ERIKA TAYLOR, Voice of OC

University of Southern California students and faculty are working to conserve and study this type of giant kelp for its ability to withstand rising ocean temperatures. 

Karina Arzuyan, a PhD candidate working on the Super Kelp Sequencing Project, looks at a kelp gametophtye under a microscope on Sept. 5, 2025. Credit: ERIKA TAYLOR, Voice of OC

“We are seeing some species die out. We are seeing other species that are better capable of surviving in these warm waters, such as Sargassum horneri, which is an non-native species from Japan that’s taking over parts of Catalina Island, displacing some kelp populations that we have. Some just do better than others because of abiotic conditions, some are okay with warmth, but a degree or two is a massive difference for lots of organisms,” said Karina Arzuyan, a PhD candidate working on the Super Kelp Sequencing project. 

A molecular biology lab inside Ray R. Irani Hall on the University of Southern California campus on Sept. 5, 2025. Credit: ERIKA TAYLOR, Voice of OC

Arzuyan explained that the project studies the kelp’s genome, exploring how and why the proteins in super kelp respond to heat. 

After an initial project in partnership with University of Wisconsin-Milwaukee on accelerating the growth of kelp, biologist and USC professor Dr. Sergey Nuzhdin established a nonprofit seed bank known as Kelp Ark to preserve the collections.

The seed bank and nursery currently has over 2,600 unique strains of kelp representing 12 different species within their collection like giant kelp, laminaria, feather boa and bull kelp. 

Karina Arzuyan, a PhD candidate working on the Super Kelp Sequencing Project, grabs a container of kelp gametophtyes from a lab refrigerators on Sept. 5, 2025. Credit: ERIKA TAYLOR, Voice of OC

Hayden Schneider looks at kelp gametophytes kept in lab refrigerators under red light on Sept. 10, 2025. Credit: ERIKA TAYLOR, Voice of OC

Although the environmental benefit of kelp farming has been scrutinized, the use of kelp extract in everyday products could become more widespread through kelp farming.

“If you farm kelp, then you will increase uptake of carbon by the ocean very substantially. And if it is the real goal, in addition to that, biofuels, bioplastics and biostimulants, most importantly, can be extracted from kelp to feed the economy,” said Dr. Nuzhdin. 

Dr. Nuzhdin noted that California’s agricultural economy would benefit from the use of kelp-based biostimulants — compounds that would boost the productivity and drought-resistence of crops.

Biologist and University of Southern California professor Dr. Sergey Nuzhdin stands in the aquaculture lab on campus on Sept. 5, 2025. Credit: ERIKA TAYLOR, Voice of OC

Aside from biostimulants, Bracken said he is “particularly excited” about innovations in plastic products made of seaweed, which could include nearly any plastic product like tennis shoes.

“Kelp can grow really fast, and so there’s this idea that we could farm them and provide all the same benefits to the ocean, but then you can harvest it and create bio-based products that could be solutions to fight climate change that we haven’t even come up with yet,” said Hayden Schneider, outreach and partnership associate with Kelp Ark. “They would work with nature versus working against it.” 

Hayden Schneider, outreach and partnership associate with Kelp Ark, looks at kelp gametophytes kept in lab refrigerators under red light on Sept. 10, 2025. Credit: ERIKA TAYLOR, Voice of OC

This story was co-published by the Voice of OC and Annenberg Media.

Erika Taylor is a Voice of OC Tracy Wood Reporting Fellow and photojournalist. Contact her at etaylor@voiceofoc.org or @camerakeepsrolling.

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