Volcanic carbon dioxide vents show ecosystem effects of ocean acidification

A high-profile Royal Society report in 2005, followed by similar reports worldwide, high-lighted the fact that relatively little is known about the ecosystem effects of ocean acidification. Work to date has been largely limited to short-term experiments on isolated aspects of marine communities. Hall-Spencer et al. adopted an alternative approach, tracking the response to CO2 release from volcanic vent sites off the island of Ischia in the Bay of Naples, where ocean acidification has prevailed perhaps for centuries. Typical rocky shore communities rich in calcareous organisms thrive at normal pH, shifting to communities lacking scleractinian corals and low in sea urchin and algal numbers at low pH. The results show that such sites can act as natural experiments against which to test laboratory and modelled predictions of the effects of ocean acidification.