A novel approach to carbon capture in low-oxygen aquatic environments, such as fish farms, could help address rising global temperatures while offering a cost-effective solution, according to a recent study published in Nature Food.
Lead researcher Mojtaba Fakhraee, assistant professor of Earth sciences at the University of Connecticut, highlighted that traditional emission-reduction methods alone are insufficient to maintain global temperature increases below 2°C, as stipulated by the Paris Agreement. The study focuses on carbon capture — capturing CO2 emissions from industrial sources — as an essential complement to conventional reduction strategies.
Fakhraee, alongside Noah Planavsky, professor of Earth and planetary sciences at Yale University, developed a model demonstrating how alkalinity production through enhanced iron sulfide formation in fish farms can capture up to 100 million tonnes of CO2 annually.
Their research found that adding iron to fish farms reacts with accumulated hydrogen sulfide, reducing its toxicity and increasing alkalinity. This process raises carbonate saturation levels, enhancing CO2 capture.
The model holds significant potential in fish-farming nations like China and Indonesia. China alone could capture nearly 100 million tonnes of CO2 annually, the researchers estimate.
“Fish farms are ideal for this approach because they are heavily influenced by human activity and offer an opportunity to simultaneously reduce toxic sulfide levels while capturing carbon,” said Fakhraee.
Besides addressing climate change, this method could benefit fish farming by reducing hydrogen sulfide toxicity, which often leads to higher fish mortality rates and reduced productivity.
“This approach not only supports carbon neutrality but also enhances fish farm sustainability by promoting healthier fish populations,” Fakhraee added.
The researchers emphasized that their method offers long-term carbon storage, with the captured CO2 remaining sequestered for thousands of years.
Fakhraee concluded, “This is just one possible pathway for large-scale carbon capture. By neutralizing emissions and improving fish farm viability, this method has the potential to transform the aquaculture industry into a more sustainable enterprise.”