Changes in temperature, oxygen level, acidity and other ocean properties directly affect marine ecosystems through shifts in biogeography, phenology, productivity and trophic interactions. This talk highlights some of the latest understanding on the extent to which climate change and ocean acidification are affecting global marine biodiversity and fisheries. As shown by analyzing global marine biogeography records and fisheries data, ocean warming has already been altering marine species assemblages in the past four decades. Moreover, mapping of vulnerability of almost 1000 species marine fishes in the global ocean based on their exposure to climate stressors, biological sensitivity and adaptive capacity indicates that most of the studied marine fishes become highly vulnerable to climate change under high greenhouse gas emission scenarios. Such findings corroborate with results from simulation modeling of global shifts in distributions of marine fishes and invertebrates, highlighting the large climate risks of regional ecosystems, particularly in the tropics and Arctic Ocean, in terms of changes in community structure and key ecosystem services such as fisheries. The resulting economic impacts are particularly large in developing countries with low adaptive capacity. Such evidence demonstrates the multi-facet responses of marine ecosystems to climate change, identify hotspots of vulnerable ocean regions, and highlights the need for immediate actions and their scope to mitigate the impacts from climate change and ocean acidification.
Dr. William Cheung is an Associate Professor at the Institute for the Oceans and Fisheries [UBC profile], UBC and the Director (Science) of the Nippon Foundation-UBC Nereus Program [www.nereusprogram.org]. His main research areas include understanding the responses and vulnerabilities of marine ecosystems and fisheries to global change, and examining trade-offs in managing and conserving living marine resources. His works cut across multiple disciplines, from oceanography to ecology, economics and social sciences, and range from local to global scales.