University of Otago, New Zealand


Te Tari Hua-Ruanuku

Greatest mass extinction driven by acidic oceans, study finds

Sunday 12 April 2015

Dr Matthew Clarkson

Changes to the Earth’s oceans, caused by extreme volcanic activity, triggered the greatest extinction of all time, according to new findings by an international research team that includes a University of Otago scientist.

The event, which took place 252 million years ago, is known as the ‘Great Dying’ and wiped out more than 90 per cent of marine species and more than two-thirds of the animals living on land.

It happened when Earth’s oceans absorbed huge amounts of carbon dioxide from volcanic eruptions, the researchers say. This changed the chemical composition of the oceans – making them more acidic – with catastrophic consequences for life on Earth.

The study, co-ordinated by University of Otago Department of Chemistry postdoctoral fellow Dr Matthew Clarkson while a PhD student at the University of Edinburgh, is the first to show that highly acidic oceans were to blame.

The findings appear in the leading international journal Science. The study was carried out in collaboration with the University of Bremen, Germany, and the University of Exeter, together with the Universities of Graz, Leeds, and Cambridge.

News @ Otago - Friday 10 April

Matthew's article can be found at