Overview of the study

The preprint, titled "Comprehensive quantification of production costs for large-scale kelp aquaculture and cost reduction opportunities", presents a techno-economic model that couples biological growth, structural loads, operations and economics to estimate the cost of producing kelp at large scale. The authors — Zachary Moscicki, Adam St. Gelais, Struan Coleman, Alexander Kinley, Tobias Dewhurst and colleagues— apply the model to a hypothetical 405 ha Saccharina latissima farm located 20 km offshore at 100 m water depth in the Gulf of Maine.

Key findings

In the baseline scenario, using currently available equipment and practices, the model estimates a cost of production (COP) of $2,618 per fresh tonne. By redesigning the farm structure and vessel operations – including purpose-built vessels, mechanized harvesting and processing, on-board biomass storage and cultivation at depths optimized for light availability – the COP drops by about 85 % to $383 per tonne. Sensitivity analyses show the baseline scenario is most affected by wave-height limits, vessel cruising speed, yield and distance to port, whereas the improved scenario is dominated by yield, component lifespan and structural costs. The authors stress that no single innovation drives the cost reductions; rather, integrated structural and operational improvements are needed.

Broader context

Large-scale kelp farming could diversify food production and provide low-carbon feedstocks. However, economic uncertainty at high-energy offshore sites has limited investment. This study demonstrates that a comprehensive techno-economic approach can identify design drivers and cost-savings opportunities. By modelling the interactions among structure design, farm operations and biological growth, the authors provide actionable insights for developers, regulators and investors considering offshore kelp projects.

The preprint is available on the Kelson Marine website and Frontiers in Aquaculture. Feedback is welcome while the study undergoes peer review.

Cost analysis reveals that the baseline production cost is $2,618 per tonne of fresh kelp. By redesigning farm structures and adopting improved operations – such as purpose‑built vessels, mechanized seeding and harvesting, deeper cultivation, and at‑sea processing and storage – the improved scenario reduces costs to $383 per tonne, an 85 % reduction. Sensitivity analysis shows cost of production is most sensitive to vessel day rates, kelp yield, maintenance and harvest labour, and farm structure cost; improvements in these areas drive the greatest savings.

Large‑scale kelp farming can diversify food and feedstocks, but economic uncertainties hinder investment. This comprehensive techno‑economic analysis reveals cost drivers and reduction opportunities, offering insights for designing efficient farms and advancing sustainable aquaculture. The preprint is available for review and feedback to accelerate innovation and investment.