Edible Seaweeds as Climate Change Mitigators: Assessing Carbon Sequestration Potential of Mozuku Farms in Okinawa, Japan

Human activities have disrupted the carbon balance, releasing excess CO₂ into the atmosphere and causing climate change, ocean acidification, and extreme weather events. These effects contribute to a global food crisis, leaving billions facing food insecurity and malnutrition. One proposed solution is biosequestration, which involves the protection and propagation of natural systems that capture CO₂. Seaweeds are among the most productive ecosystems with significant carbon capture potential. Notably, they are also a cost-effective and nutritious source of protein and calories that could help to alleviate food insecurity without straining arable land and water resources. This study examines a community-driven Mozuku seaweed farm in Okinawa, Japan. Unlike many other seaweed mCDR studies, we focus on the carbon uptake potential during the growth phase, with the final product intended for consumption. We developed a framework for assessing Net Ecosystem Metabolism and ecosystemic effects of the farm by combining physical (flow speed/direction, significant wave height) and chemical (TA, pH, Oxygen, Nutrients, etc.) measurements upstream and downstream with drifters, discrete sampling, and in-situ sensors. To complement this, we evaluate the release and degradation of dissolved organic carbon through aforementioned methods and incubations, lending insight to the farm’s carbon uptake potential and associated longevity. Ultimately, this study aims to assess the potential for sustainable seaweed cultivation to mitigate climate change.

Presentation Preference: Either

Primary Presenter: Cheyenne Bridge, University of California, San Diego (rabridge@ucsd.edu)

Authors:

Cheyenne Bridge, UCSD, SIO  (rabridge@ucsd.edu)

Andreas Andersson, UCSD, SIO  (aandersson@ucsd.edu)

Yuna Zayasu, UCSD, SIO  (yuzayasu@ucsd.edu)

Max Rintoul, Institute for Marine and Antarctic Studies  (msrintou@ucsd.edu)

Sam Kekuewa, UCSD, SIO  (skekuewa@ucsd.edu)

Satoshi Mitarai, Okinawa Institute of Science and Technology  (satoshi@oist.jp)

Heng Wu, Okinawa Institute of Science and Technology  (HENG.WU@oist.jp)

Reggie Spaulding, Sunburst Sensors  (reggie@sunburstsensors.com)

Brandon Stephens, National Taiwan University  (bstephens@ntu.edu.tw)

Loretta Roberson, Marine Biological Laboratory  (lroberson@mbl.edu)

Adrienne Sutton, NOAA PMEL  (adrienne.sutton@noaa.gov)

Tran Nguyen, UCSD, SIO  (tbnguyen@ucsd.edu)

Lihini Aluwihare, UCSD, SIO  (laluwihare@ucsd.edu)