KOSMOS 2013 Gullmar Fjord long-term mesocosm study: Mesozooplankton abundance

Ocean acidification (OA) is one of the major symptoms of the current increase in atmospheric CO2. Here, we present results from a mesocosm experiment carried out during 113 days in the Gullmar Fjord, Skagerrak coast of Sweden, studying plankton responses to predicted end-of-century pCO2 levels. Abundances of both copepods (Pseudocalanus acuspes, Temora longicornis, and Oithona similis) and hydromedusae (Hybocodon prolifer and Aglantha digitale) responded to pCO2. Furthermore, stage-specific pCO2 sensitivities were detected in copepods, copepodites being the most sensitive stage.