Comparing Kelp Conveyance Strategies for Marine Carbon Dioxide Removal with Farmed Macroalgae

Sequestration of carbon dioxide via sinking of farmed seaweed into the ocean is a promising strategy to the ever-growing need to achieve negative emissions of carbon dioxide. A key component to the durability of the strategy is the method to which seaweed biomass is conveyed to the seafloor. The purpose of this white paper is to introduce four different conveyance techniques, plans for how each technique will be implemented at smaller scales, and describe how each conveyance method will be modeled. The development of each conveyance technique is guided by the balance between overcoming the positively buoyant kelp biomass, overall feasibility given resources and technology, and the ability to monitor, validate and record the environmental impact of sinking Giant Kelp biomass. We plan to use a combination of laboratory and field-based experiments at a smaller scale, to acquire information about sinking rates, dissolved organic carbon release rates, and kelp decomposition rates for each conveyance method. Lastly, the white paper will describe how the data acquired from the laboratory and field-based experiments will inform a series of models, that when combined together, will simulate the durability and the environmental impact of each conveyance method if adopted to scale.