New research suggests volcanic eruptions 252 million years ago deposited considerable quantities of carbon dioxide into the oceans, causing a rise in acidification that subsequently led to mass extinctions of most species throughout the world’s seas.
During this extinction event, the researchers argue, 90 percent of marine species were wiped out, along with two-thirds of terrestrial plants and animals. In earlier studies scientists proposed that volcanoes or ocean acidification could have been involved in the die-offs. To assess this the researchers in the new study were able to measured
pH more directly than before. A drop in pH means a rise in acidity.
The study is summarized by Nature News. By analyzing boron isotopes from Permian-era rocks in the United Arab Emirates, the researchers noted that a sudden drop in pH occurred over 10,000 years. This was, the researchers argue, at the tail end of what they are terming the “Great Dying.”
Expanding on this measurement and subsequent theory, lead author Matthew Clarkson of the University of Edinburgh’s School of GeoSciences said in a research note: “Scientists have long suspected that an ocean acidification event occurred during the greatest mass extinction of all time, but direct evidence has been lacking until now. This is a worrying finding, considering that we can already see an increase in ocean acidity today that is the result of human carbon emissions.”
The study has been published in the journal
Science. The study is headed “Ocean acidification and the Permo-Triassic mass extinction.”
