Acid Oceans

The UK's chief scientist says the oceans face a serious and growing risk from man-made carbon emissions.

The oceans absorb about a third of the CO2 that’s being produced by industrial society, and this is changing the chemistry of seawater.

Sir Mark Walport warns that the acidity of the oceans has increased by about 25% since the industrial revolution, mainly thanks to manmade emissions.

He told BBC News: “If we carry on emitting CO2 at the same rate, ocean acidification will create substantial risks to complex marine food webs and ecosystems.”

He said the current rate of acidification is believed to be unprecedented within the last 65 million years – and may threaten fisheries in future.

Sir Mark’s comments come as recent British research suggests the effects of acidification may be even more pervasive than previously estimated.

Until now studies have identified species with calcium-based shells as most in danger from changing chemistry.

But researchers in Exeter have found that other creatures will also be affected because as acidity increases it creates conditions for animals to take up more coastal pollutants like copper.

 “It’s a bit of a shock, frankly,” said biologist Ceri Lewis from Exeter University, one of the report’s authors. “It means the effects of ocean acidification may be even more serious than we previously thought. We need to look with new eyes at things which we thought were not vulnerable.”

The lugworm study was published in Environmental Science and Technology.

Another study from Dr Lewis not yet peer-reviewed suggests that sea urchins are also harmed by uptake of copper. This adds to the damage they will suffer from increasing acidity as it takes them more and more energy to calcify their shells and spines.

This is significant because sea urchins, which can live up to 100 years, are a keystone species - grazing algae off rocks that would otherwise be covered in green slime.