loading page

Nearshore Macroalgae Cultivation for Carbon Sequestration by Biomass Harvesting: Evaluating Potential and Impacts with An Earth System Model
  • +1
  • Jiajun Wu,
  • Wanxuan Yao,
  • David Peter Keller,
  • Andreas Oschlies
Jiajun Wu
GEOMAR Helmholtz Centre for Ocean Research Kiel

Corresponding Author:[email protected]

Author Profile
Wanxuan Yao
GEOMAR Helmholtz Centre for Ocean Research
Author Profile
David Peter Keller
Helmholtz-Zentrum für Ozeanforschung Kiel, GEOMAR
Author Profile
Andreas Oschlies
Helmholtz-Zentrum für Ozeanforschung Kiel, GEOMAR
Author Profile


This study introduces an ocean-based carbon dioxide removal (CDR) approach: Nearshore Macroalgae Aquaculture for Carbon Sequestration (N-MACS). By cultivating macroalgae in nearshore ocean surface areas, N-MACS aims to sequester CO2 with subsequent carbon storage. Utilizing an Earth System Model with intermediate complexity (EMIC), we explore the CDR potential of N-MACS alongside its impacts on the global carbon cycle, marine biogeochemistry and marine ecosystems. Our investigations unveil that coastal N-MACS could potentially sequester 0.7 to 1.1 GtC yr-1. However, it also significantly suppresses marine phytoplankton net primary productivity because of nutrient removal and canopy shading, counteracting approximately 30% of the N-MACS CDR capacity. This suppression of surface NPP, in turn, reduces carbon export out of the euphotic zone to the ocean interior, leading to elevated dissolved oxygen levels and diminished denitrification in present-day oxygen minimum zones. Effects due to harvesting-induced phosphorus removal continue for centuries even beyond the cessation of N-MACS.
04 Mar 2024Submitted to ESS Open Archive
04 Mar 2024Published in ESS Open Archive