91. Combined effects of ocean acidification and metals on sea urchin and oyster larval development

N.Dorey*, E. Maboloc, K. Chan

Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong

We live in a multi-stressor world where oceans are impacted by both global (e.g. CO2-driven climate change and ocean acidification) and local pressures. Coastal marine organisms are already challenged by anthropogenic stressors such as pollutants, that may magnify the impacts of future global changes. For instance, ocean acidification is likely to change metal speciation as well as bioaccumulation and, consequently, metal toxicity. There is few information available on the effects of these interactions on marine biota. In this study, we provide insight on the combined effects of ocean acidification and copper on the larval development of the sea urchin Heliocidaris crassispina and the oyster Crassostrea hongkongensis. In laboratory culture, sea urchin larvae appeared quite robust to predicted pH changes as well as to high levels of copper contamination, albeit some morphometric changes. The association of both stressors significantly increased larval mortality, anomalies and respiration. We still lack an understanding of how biological mechanisms respond to co-occurring factors such as metal contamination and ocean acidification, making accurate projections regarding the future of ecologically- and economically- important marine ecosystems difficult.