Macroalgae on a macro scale: Overcoming the scaling challenges of seaweed cultivation for climate mitigation

There is growing interest in seaweed cultivation as an environmentally regenerative form of aquaculture, a source of biofuels, low-carbon food and animal feed, and a potential strategy for carbon sequestration. To help address questions about the expansion of seaweed cultivation we have developed a dynamical model, the MacroAlgae Cultivation MODeling System (MACMODS), to investigate farm-scale design and siting, environmental feedbacks, as well as global-scale seaweed production potential. At the regional scale, MACMODS integrates a regional ocean model (ROMS) with a fine-scale large eddy simulation (LES) model that resolves within-farm canopy transport and turbulent mixing and a macroalgal growth model that accounts for hydrodynamically-mediated biological processes like the enhancement of nutrient uptake due to flow and waves. We demonstrate the utility of this framework for cultivation of giant kelp, Macrocystis pyrifera, along the California coast. At the global level, we use MACMODS alongside a technoeconomic model to address the potential productivity, costs, and potential climate benefits of seaweed farming.

Speaker: Kristen Davis, Stanford University