Found in shallow coastal waters worldwide, seagrass meadows are noteworthy emitters of methane into the atmosphere. Yet only a few studies have quantified their methane contribution and little is known about the metabolic processes and microorganisms involved in it.
A study published last week (February 14) in PNAS describes the mechanisms by which methane is formed in meadows of Posidonia oceanica, a seagrass species endemic to the Mediterranean Sea. The metagenomes from the sediments surrounding the plants’ roots suggest that microorganisms from different archaeal groups are metabolizing diverse compounds present in the plant tissue to generate methane. According to these findings, these microbial communities produce methane both while the seagrasses are alive and long after they have died.
Seagrasses, together with mangroves and salt marshes, are considered blue carbon ecosystems—they sequester, store, and bury carbon from the atmosphere, keeping the levels of carbon dioxide from increasing even more. However, they ...
