Christopher E. Cornwall1, Aleluia Taise1, Yaelle Sarid-Segal1, Katjuschka Siegers1, Imke Böök1, Arlo McMahon1, Erik Krieger1
1School of Biological Sciences and Coastal People Southern Skies, Victoria University of Wellington
Multiple climate change drivers are manifesting in our oceans simultaneously. Ocean acidification reduces the calcification rates of calcareous taxa and alters dissolved inorganic carbon uptake in seaweeds, while ocean warming and increasing frequencies, durations and intensities of marine heatwaves cause physiological stress to many marine species. Predicting the impacts of marine heatwaves is complex, with differing durations and intensities of thermal anomalies possibly eliciting responses that vary by species, population or individual. Ocean acidification can be classified as a multiple driver, with changes in HCO3–, H+, CO2 and possibly CO32- all having physiological ramifications for various seaweed species. Here I give an overview of insights gained over the last four years of manipulation experiments with seaweeds in the North Island of Aotearoa New Zealand, focusing on the identification of generalities in their physiological responses to multiple drivers of change.