Sea creatures ‘as bad as cattle for methane’

POPULATIONS of mussels, clams and oysters produce “ridiculous” levels of climate-warming gases, on a par with herds of cattle, a study shows.

Scientists have said the ocean creatures produce large amounts of the strongest greenhouse gases – methane and nitrous oxides – from the bacteria in their guts. This methane bubbles out of the water, contributing to global warming, having 28 times greater warming potential than carbon dioxide. The finding are significant as it has been proposed to expand the farming of oysters, mussels and clams as a mass food source.

Scientists from Cardiff University and Stockholm University found a tenth of all methane emissions from the Baltic Sea may be due to clams and worms. This was equivalent to the methane given off by 20,000 dairy cows – a tenth of the number of all the dairy cows in Wales – or one per cent of the entire UK dairy cow herd.

Dr Stefano Bonaglia, the study’s lead author from Stockholm University, added: “It sounds funny but small animals in the sea floor may act like cows in a stable, both groups being important contributors of methane due to the bacteria in their gut.”

The study was published in the journal Scientific Reports.