Impact of ocean acidification on Corallium rubrum (L. 1758): an experimental approach

Ocean acidification is considered as a global threat to marine ecosystems (Hoegh-Guldberg et al. 2007, Fabry et al. 2008, Doney et al. 2009). It is caused by rising atmospheric carbon dioxide (CO₂) concentrations, which drive changes in seawater carbonate chemistry and reduce pH (Gattuso & Buddemeier 2000). This process of ocean acidification is underway (Solomon et al. 2007) and will accelerate with increasing CO₂ emissions over the course of the current century (Caldeira & Wickett 2003). Many marine organisms, from phytoplankton to fish, are sensitive to changes in carbonate chemistry, and their responses to the predicted changes could lead to profound ecological shifts in marine ecosystems (Doney et al. 2009, Kroeker et al. 2010). Marine organisms vary broadly in their responses to ocean acidification, in part due to the wide variety of processes affected (e.g., dissolution and calcification rates, growth rates, development and survival), making it challenging to predict how marine ecosystems will respond to ocean acidification.
Our results provide first evidence of the effects of ocean acidification on biocalcification, growth and polyps’ activity of C. rubrum, an octocoral endemic to the Mediterranean Sea, with an high economic value of its axial carbonate skeleton and, for this reason, harvested and traded worldwide since ancient times (Santangelo & Abbiati 2001).