Using scientific diving to investigate the long-term effects of ocean acidification at CO2 vents

Abstract

We are using SCUBA to document ecosystem responses to long-term ocean acidification at volcanic CO2 vents. There are 30% reductions in biodiversity at average pH 7.8-7.9 (minimum pH 7.4), compared with areas with normal pH (8.1-8.2). Some groups (seagrasses and many algae) are tolerant of the increased CO2 levels but others (corals, sea urchins and calcified algae) are removed from the ecosystem. Transplant experiments show dissolution of calcareous organisms and our study demonstrates, for the first time, what happens to coastal marine ecosystems when key groups of species are killed due to rising CO2 levels.