Anthropocene Magazine: How seaweed farms could change the arithmetic of ocean carbon capture - for the better.

Seaweed farms cover 3.5 million hectares of ocean and are busy locking away vast amounts more carbon than we realise, say researchers. In a new study they argue that in estimates of their blue carbon potential, we’ve been overlooking the unique way that seaweeds interact with seawater, which makes it absorb more CO2.  "Most discussions about seaweed and climate focus on how seaweed captures carbon as it grows. The concern has been that much of that carbon might be released again when the seaweed decomposes,” says Mojtaba Fakhraee, Department of Earth Sciences, University of Connecticut. (However) their model found that increased biomass from seaweed farms was linked to dramatically enhanced levels of alkalinity. “Higher alkalinity allows seawater to hold more carbon in dissolved form without becoming acidic,” Fakhraee explains. “This shifts the balance so that CO2 naturally moves from the atmosphere into the ocean. Read ON.