Shell Shock! Damage to marine ecosystems revealed as CO2 emissions continue to rise

A team of marine experts is helping predict the future of coastal ecosystems after discovering that warming temperatures may exacerbate ocean acidification.

In a paper published in full by Nature Climate Change magazine this month, the scientists warn that rapidly deteriorating Mediterranean coastal ecosystems are further threatened by increasing CO2 levels.

Riccardo Rodolfo-Metalpa, Plymouth University Postdoctoral Research Fellow, based at the International Atomic Environmental Agency (IAEA), has been studying marine life off the Island of Ischia in Italy where carbon dioxide bubbles up through vents in the seabed due to volcanic activity around Mount Vesuvius in Naples.

Rodolfo-Metalpa, said: “Our transplant experiments with corals, limpets and commercially important mussels have shown the severe risks associated with increasing carbon dioxide emissions for marine life. These animals try to grow their shells and skeletons faster but they simply dissolve away. Mediterranean coastal ecosystems are being degraded by increasing temperatures and we now know that this warming can make the effects of ocean acidification worse.”

Jason Hall-Spencer, a Reader in Marine Biology at Plymouth University, coordinated the team of scientists from Monaco, Italy, Israel and France as part of a project to assess the risks related to ocean acidification and seawater temperature increase at organism, ecosystem and economic scales.

Hall-Spencer said: “Carbon dioxide vents provide natural laboratories that show us what coastal areas might look like if ocean acidification continues to worsen. They also help us predict how people will be affected if CO2 levels continue to rise rapidly. We see major losses in biodiversity and the aquaculture industry is right to be nervous about the effects of carbon dioxide.

“This research adds to a raft of new studies that highlight an urgent need for both lowering carbon dioxide emissions and increasing marine conservation efforts worldwide to slow the loss of marine biodiversity and build resilience in the coastal systems we rely upon.”

The Intergovernmental Panel on Climate Change’s (IPCC) 4th Assessment Report estimates that unless CO2 emissions are greatly reduced by the end of the century, mean surface ocean pH will decline from the current level of 8.1 to 7.8, due to rising atmospheric CO2 concentrations.

This new study builds on work published by the team in Nature and National Geographic Magazine and documents the corrosive effects of acidified water on mollusc shells and coral skeletons.