Ocean acidification (OA) is a consequence of human activities that is threatening marine species and ecosystems around the world. The rate and scale of changes in marine chemistry is unprecedented in human history. Coastal upwelling ecosystems are particularly vulnerable to these changes because they are already naturally exposed to corrosive waters; upwelling of deep waters with high CO2 concentrations results in a lower aragonite saturation state (Ωar), which determines whether aragonite precipitates (at supersaturated conditions; Ωar>1) or dissolves (undersaturated conditions; Ωar<1). The absorption of anthropogenic CO2 in upwelling systems is causing longer, more intense and severe OA conditions that ultimately result in declining habitat suitability (Feely et al., 2004; Feely et al., 2008; Gruber et al., 2012; Hauri et al., 2013; Bednaršek et al., 2014a). This substantially impacts marine calcifiers such as pteropods, free-swimming marine planktonic snails. Because of their thin aragonite shells, which rapidly dissolve at Ωar<1, they are extremely sensitive to OA (Bednaršek et al., 2012b; 2014a,b). (…)
Bednaršek N., McCabe R. & Klinger T., 2016. Pteropod shell dissolution as an indicator of ocean acidification across different upwelling regimes. IMBER Update 30. Article.
