Wednesday, September 26, 2012

Speed of ocean acidification concerns scientists – ‘Our current acidification rates are unparalleled in Earth history’

http://www.desdemonadespair.net/2012/09/speed-of-ocean-acidification-concerns.html

Idealized diversity trajectories of the calcareous and organic fossil lineages discussed in the text. Extinction and radiation suggest events of major environmental change throughout the past 300 My. Calcareous plankton is shown in black, calcareous benthos in blue, and organic fossils in green, and the line thickness indicates relative and smoothed species richness. Highlighted events (vertical red lines) have been associated with potential ocean acidification events. Hönisch, et al., 2012

26 September 2012 (University of Bristol) – Speaking at the Third International Symposium on the Ocean in a High-CO2 World this week in Monterey, California, Dr Daniela Schmidt, a geologist from the University of Bristol, warned that current rates of ocean acidification are unparalleled in Earth history.

Dr Schmidt of Bristol's School of Earth Sciences said: "Ocean acidification has happened before sometimes with large consequences for marine ecosystems.  But within the last 300 million years, never has the rate of ocean acidification been comparable to the ongoing acidification.

She added that the most comparable event, most likely 10 times slower than the current acidification, was 55 million years ago.

"At that time, species responded to the warming, acidification, change in nutrient input and loss of oxygen – the  same processes that we now see in our oceans.  The geological record shows changes in species distribution, changes in species composition, changes in calcification and growth and in a few cases extinction," she said.

"Our current acidification rates are unparalleled in Earth history and lead most ecosystems into unknown territory."

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