Production of Red Seaweed to Mitigate Methane Emissions in California Livestock

Asapragopsis taxiformis growing at Catalina IslandResearch teams at UC San Diego and UC Davis are collaborating to explore the use of a red seaweed (Asparagopsis taxiformis) as a feed supplement to reduce methane emissions from enteric fermentation in livestock. The CNI award will help to advance the understanding of Asparagopsis cultivation and production techniques to increase supply and decrease costs of the red seaweed, needed before this climate mitigation approach can be scaled widely. Further, this study will assess the economic feasibility and net carbon benefits of incorporating this approach into the UC offsets program.

showing cell structure under a microscope in the Smith LabEnteric fermentation in cattle and other ruminants comprises approximately 4% of global greenhouse gas emissions, and global demand for beef and dairy is growing rapidly. At present, there are no widely viable supply-side interventions to reduce emissions from enteric fermentation in ruminant digestion. Ongoing experiments show the red alga Asparagopsis can decrease these emissions by 30-90% (depending on the quality and quantity of seaweed fed). In California alone, this novel climate mitigation opportunity has the potential to reduce emissions by millions of tonnes of carbon dioxide equivalents per year once implemented at scale.

Despite the potential for this seaweed to mitigate methane emissions, it is not currently available at a commercial scale and the biomass that has been used in previous studies was all entirely wild harvested. These limitations highlight the need to develop techniques and best practices for culturing Asparagopsis to ensure a sustainable source of this material is available in California and beyond. Additionally, while initial scientific results are promising, economic analyses are needed to determine if Asparagopsis offset projects are cost-effective.

Asapragopsis taxiformis growing in lab-based cultures.Asapragopsis taxiformis growing in lab-based cultures.

Images of Asapragopsis taxiformis (top left) growing at Catalina Island, (middle right) showing cell structure under a microscope in the Smith Lab, and (just above) growing in lab-based cultures.

To determine the viability of Asparagopsis offset projects, our team will contribute to research into Asparagopsis cultivation, estimate net greenhouse gas benefits, and analyze the economics of Asparagopsis feed supplement offset projects. This project will advance our understanding of the viability of Asparagopsis projects and target areas for production, cost, and greenhouse gas improvements to increase project viability.

Project Lead/Key Members:

Dr. Jen Smith
Professor, Marine Biology
University of California San Diego


Patrick Cage
Project Manager
Recently graduated UCSC masters student

In partnership with startup Blue Ocean Barns

Project Updates

The CNI Red Seaweed Project initiated in February 2021. Stay tuned for more results soon!  



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