Seaweed ocean farms can help combat climate change, says Dr Franziska Elmer, head scientist at UK aquaculture firm Seafields.
While reducing CO2 emissions is vital, it’s insufficient without sequestering historic CO2 levels. Traditional solutions like mass tree planting have limitations, prompting a shift in focus towards the ocean’s potential for carbon sequestration. Could ocean farms of seaweed be the solution to climate change?
Sargassum, a floating seaweed, has emerged as a promising candidate. Despite its nuisance status, it boasts rapid growth and carbon sequestration capabilities.
Dr. Elmer, motivated by climate activists like Greta Thunberg, quit her job teaching marine ecology to dedicate herself to climate solutions. Recognising Sargassum’s potential, she embarked on a journey to turn this natural disaster into a cornerstone of the blue economy.
And together with colleagues, Fran started a podcast on Sargassum. It was here where Fran first met Professor Victor Smetacek – Chief Scientific Advisor at Seafields – who first had the clear vision for the potential of cultivating sargassum for large-scale carbon dioxide sequestration. A few months later, entrepreneurs knocked on his door, and Seafields was born.
Dr Elmer explains, “At Seafields, we aim to use Sargassum to sequester carbon at a gigatonne scale. Initial operations focus on the Caribbean, where Sargassum accumulates, creating economic and environmental challenges.
“Our approach involves cultivating, harvesting, and processing Sargassum for sustainable carbon sequestration. By transforming Sargassum into valuable products, they aim to mitigate its negative impacts while creating jobs and fostering blue economy growth.
“Ocean-based solutions, including growing algae, offer promising avenues for carbon capture. Sargassum, particularly S. natans and fluitans, stands out for its rapid growth and carbon sequestration efficiency. Seafields plans to cultivate Sargassum in aquafarms, diverting it from beaches and landfills. These aquafarms will store Sargassum alive, ensuring a year-round supply of biomass for carbon sequestration.
“As natural Sargassum reserves in the Caribbean diminish, Seafields plans to scale up offshore in ocean deserts like the Subtropical Gyres. Double upwelling pipes will supply nutrients from deep waters to sustain Sargassum growth. Carbon sequestration will occur through harvesting, processing, and sinking Sargassum biomass into the deep ocean. Rigorous monitoring using biogeochemical sensors and collaboration with researchers will ensure the effectiveness and environmental safety of this approach.
“Sargassum offers a range of benefits beyond carbon sequestration. Its utilisation in fertilizers, bioplastics, and biofuels presents opportunities for emission avoidance and long-term carbon storage. By sinking carbon-rich leftover biomass, Seafields enhances natural carbon cycling processes, contributing to climate mitigation efforts.
“The Great Atlantic Sargassum Belt, a massive algal bloom, poses challenges to coastal ecosystems and economies. Seafields aims to prevent Sargassum influxes to coastal areas by converting it into valuable products. This not only mitigates methane emissions but also alleviates pressure on coastal ecosystems and economies.
“Seafields’ journey involves rigorous testing and refinement of aquafarm designs and carbon sequestration methods. Collaborations with research institutions and scientific expeditions provide essential data for scaling up operations. By 2025, Seafields anticipates significant progress in both sinking studies and commercial operations”.
Dr. Elmer envisions a future where ocean gardens, powered by clean energy, thrive alongside sustainable aquafarms. These ecosystems support diverse marine life while contributing to carbon sequestration efforts. Collaborations with partners to maximize nutrient extraction and develop long-lasting plastics from Sargassum demonstrate Seafields’ commitment to sustainable innovation.
In conclusion, Seafields’ pioneering efforts exemplify how innovative solutions can transform environmental challenges into opportunities for sustainable growth. By harnessing the potential of Sargassum, they pave the way for a greener, more resilient future.
About Dr Franziska Elmer
Dr Elmer has a BSc in Environmental Science, an MSc in Ecology and Evolution from ETH Zurich, and a PhD in Marine Biology from Victoria University in Wellington. She joined Seafields in 2021. She has published 15 peer reviewed articles and is the treasurer of the Association of Marine Laboratories of the Caribbean.
