Exploring Science-Based Pathways for Advancing Multi-Benefit Seaweed Farming in California

Following OST’s engagement with state agencies and the legislature in 2022 on The Science, Economics, and Policy Landscape for Seaweed Farming in California, the opportunities related to multibenefit aquaculture in California are rapidly advancing. With the growth of new markets such as methane-reducing feedstock for cows and bioplastics, and the potential of seaweed aquaculture to support climate mitigation and ecosystem restoration, the role of science-informed discourse and coordination is increasingly needed to inform California’s management and policy landscape. However, despite growing interest and investment into seaweed-based solutions, barriers to advancement remain, including permitting and regulatory complexities, high startup costs, and the need for social license to operate.

As the state considers the future of responsible, multibenefit seaweed aquaculture, OST will ensure that fit-for-purpose science is readily available to serve as a guidepost for regulatory, management, and policy decisions. Through hosting cross-sectoral convenings and engaging decision-makers, experts, and the broader public on the latest research, OST is fostering collaboration and information exchange among stakeholders and elevating science and information needs.

OST hosted a Special Session on Restorative Aquaculture at the 104th Western Society of Naturalists meeting in 2023 to discuss the science of the potential role of aquaculture techniques in rehabilitating California’s marine ecosystems.

To educate policymakers, scientists, and the general public about the location and types of seaweed farms and innovative research happening across the state, OST developed an interactive StoryMap, “Growing Seaweed in the Golden State.” The StoryMap provides information on the status of the industry and science of seaweed aquaculture, featuring stories and insights from researchers and practitioners.

Two years in a row, Senior Science Officer Lauren Linsmayer has been invited to moderate panel discussions at the California Seaweed Festival. In 2023, a panel of industry, state government, and local officials discussed the opportunities and challenges of starting a seaweed farm in California. In 2024, grassroots nonprofit leaders highlighted the value of centering environmental justice in kelp restoration and aquaculture efforts.

To assist in identifying opportunities where new science and research, as well as existing information, can support the advancement of seaweed aquaculture, OST convened a workshop in November 2024 around the science needs of seaweed farming in California. Leveraging OST’s academic connections and capacity for providing independent, management-relevant science, we brought together scientific experts and state agency representatives for a roundtable discussion. The workshop summary report can be found here.

Then, in December 2024, OST and California Sea Grant co-hosted a symposium on the economics of seaweed farming in California. The event convened government agencies, academic researchers, industry representatives, and investors to explore farmed seaweed’s potential role in California’s blue economy through identifying economic opportunities and barriers and evaluating potential seaweed farming scenarios. The symposium summary report can be found here.

OST has also proactively and responsively provided information to the State Legislature on seaweed aquaculture. In May and July 2024, OST hosted two educational tours of seaweed aquaculture research and operations in Moss Landing and Humboldt Bay for policymakers. The Moss Landing event was co-sponsored by State Senator John Laird and Assemblymember Dawn Addis, and the Humboldt tour was co-sponsored by State Senator Mike McGuire and Assemblymember Jim Wood. These events served to inform state, federal, and local policymakers of science needs that policy could address and provide venues for researchers and experts to share their expertise.

This work concluded in December 2024.