In a new research, scientists have warned that as oceans become more acidic by the year 2100, coral ecosystems may start to vanish because of an invasion of opportunistic marine species like algae and mollusks, who are better able to survive in the new environment.
According to a report in New Scientist, an exploration of natural "bubble streams" of carbon dioxide (CO2) in shallow Mediterranean waters off the coast of Italy is the first to document the effects of ocean acidification in a real ocean setting.
It is well understood that oceans will become more acidic as CO2 concentrations rise is well understood. By the year 2100, ocean acidity is predicted to be 7.8 pH, compared to 8.2 pH in 1900.
But all the studies of how this will affect marine ecosystems have been carried out in laboratories, many involving organisms with shells being placed in low-pH seawater and watching them slowly dissolve.
The experiments give little indication of the degree to which this would happen in the open oceans, affected by currents and the population dynamics which regulate ecosystems.
Now, Jason Hall-Spencer and colleagues at the University of Plymouth, UK, have looked at just this process. They found a site off the island of Ischia in southern Italy where geologic CO2 naturally seeps through the seafloor.
The Ischia site offers an usual opportunity to study cool, acidified ecosystems that are not modified by the toxic effects of sulphur.