A Mediterranean Study Offers Glimpse of Acidified Oceans

A team of British scientists has documented the impact of CO₂-saturated, acidic waters on marine life, and the results indicate that many creatures, such as sea urchins and corals, will be severely stressed as greenhouse gases rise. Reporting in the journal Nature, Jason Hall-Spencer and colleagues from the University of Plymouth described their studies off the island of Ischia in southern Italy, where high levels of carbon dioxide bubble out of seafloor vents. The elevated CO₂ levels make the ocean more acidic, which softens the shells of mollusks, such as limpets, and harms the coralline algae that holds reefs together. The seabed in the acidified areas was no longer hospitable to coral ecosystems and instead was covered in seagrass and harbored more invasive species. Hall-Spencer says his studies “provide a window on the future of the oceans in a high CO₂ world.” Scientists predict that as atmospheric CO₂ levels continue to climb, the oceans will become increasingly saturated with carbon dioxide and more acidified.