New research led by Monash University has revealed that sandy coastlines, which make up half the world’s continental margins, are a previously overlooked source of methane. These microbes metabolise compounds released from decaying seaweed and seagrass, producing methane as a byproduct. It was previously understood these microbes couldn’t survive when exposed to oxygen in coastal ecosystems. But the new research, published in the journal Nature Geoscience, proves they are capable of rapid recovery and methane production following oxygen exposure. “Our work contributes to the growing body of evidence that shows methane emissions from decaying biomass like seaweed may offset much of the carbon dioxide removal attributed to coastal ecosystems.