Researchers from the University of Connecticut and Yale University have developed a model that uses fish farms for carbon capture, offering a potential solution to global carbon dioxide emissions. The study, published in Nature Food, proposes adding iron to fish farm waters to create a chemical reaction that captures carbon dioxide and improves water quality.
The model works by introducing iron into low-oxygen aquatic environments, where it reacts with hydrogen sulphide to form iron sulphide. This increases water alkalinity and carbonate saturation, allowing more CO2 to be captured. Researchers estimate that this method could capture up to 100 million metric tonnes of CO2 annually.
Lead researcher Mojtaba Fakhraee stressed the need for carbon removal to meet global climate goals, as traditional capture methods are costly and difficult to scale. Fish farms, with controlled environments, make managing the chemical reaction easier while reducing toxic hydrogen sulphide buildup, improving fish health and yields.
Countries with large aquaculture industries, like China and Indonesia, could see the most significant impact, with China alone potentially removing up to 100 million metric tonnes of CO2 annually.
Aquaculture, projected to grow 22% by 2030, currently contributes 5% to 7% of agriculture-related emissions. The researchers suggest this carbon capture method could offset much of the industry’s climate impact, leading to more sustainable fish farming.
