USING VOLCANIC MARINE CO2 VENTS TO STUDY THE EFFECTS OF OCEAN ACIDIFICATION ON BENTHIC BIOTA: HIGHLIGHTS FROM CASTELLO ARAGONESE D’ISCHIA (TYRRHENIAN SEA)

Current research into ocean acidification is mainly being carried out using short-term experiments whereby CO2 levels are manipulated in aquaria and enclosures. We have adopted a new approach in our studies of the effects of ocean acidification on Mediterranean marine biodiversity by using volcanic carbon dioxide vent systems as ‘natural laboratories’ as they cause long-term changes in seawater carbonate chemistry. A range of organisms, including macroalgae, seagrasses, invertebrates, and selected scleractinians and bryozoans have now been investigated in a shallow area located off the island of Ischia (Castello Aragonese, Tyrrhenian Sea, Italy). Our in situ observations give support to concerns, based on model predictions and short-term laboratory experiments, that ocean acidification will likely combine with other stressors (e.g., temperature rise) to cause a decrease in Mediterranean marine biodiversity and lead to shifts in ecosystem structure.