Abstract. Coralline algae are important foundation species in reefs from the tropics to the poles. They provide important ecosystem services such as provision of settlement substrate for marine invertebrates (including corals), and act to bind together reef substrate and even create reefs in some regions. Coralline algae are predicted to be one of the taxa most at risk from ocean acidification and warming. However, how and why coralline algae will respond to future ocean acidification and warming is actually poorly understood. In my presentation, I give an overview that tackles the following questions with respects to coralline algae: 1) How is calcification physiology impacted by ocean acidification? 2) What components of seawater carbonate chemistry under ocean acidification influence calcification (e.g. changes in dissolved inorganic carbon, pH or saturation state)? 3) How is calcification influenced by pH variability? 4) Will the effects of past pH-history alter responses to ocean acidification when assessed over single or multiple generations? I end by summarising what is now needed to better predict coralline algal responses to future ocean acidification.

Biography. Christopher is currently a Research Fellow at the UWA node of the ARC Centre of Excellence for Coral Reef Studies, and will commence a Rutherford Discovery Fellowship in early 2018 at Victoria University of Wellington in New Zealand. He completed a PhD at the University of Otago, in Dunedin New Zealand examing how pH variability in kelp forests could alter the impacts of ocean acidification on resident coralline algae. In 2013 to 2015 he worked at IMAS at the University of Tasmania. Most of his past work assessed how macroalgal-based ecosystems will respond to ocean acidification. He currently works with Professors Malcolm McCulloch and Ryan Lowe, applying knowledge of processes in temperate systems to coral reef settings. At UWA he also works alongside Dr Steeve Comeau to ask some of the big questions in ocean acidification science regarding how and why calcification processes of coralline algae and corals will be influenced ocean acidification. This seminar will explore some of those important findings for coralline algae.