Effects of Climate Change on Marine Ecosystems

Abstract

The impacts of anthropogenic climate change are already discernible throughout the ocean, from the equator to the poles, and from the surface to abyssal depths. Further climate change impacts are inevitable; however, their damage to marine organisms and ecosystems, and the services they provide, can be greatly reduced if greenhouse gas emissions are rapidly reduced. This review covers six main climate-related drivers (warming, acidification, deoxygenation, sea level rise and storm events, sea ice loss, stratification and nutrient supply) and their impacts on thirteen marine ecosystems, broadly defined. Seven of these are near-shore (coral reefs, kelp ecosystems, seagrass meadows, rocky and sandy intertidal, saltmarshes, estuaries and mangroves) and six are in shelf seas and the open ocean (shelf sea benthos, upper ocean plankton, fish and fisheries, cold water corals, ice-influenced ecosystems and the deep seafloor). Three cross-cutting issues are emphasised: that climate change impacts are not single factors, but interact together and with other human pressures in a multi-stressor context; that there are fast and slow climate processes in the ocean, with overall temporal uncertainties relating to future societal behaviour; and that there can be high spatial heterogeneity in marine ecosystem impacts and vulnerabilities.