Anthropogenic activities influence a suite of oceanic properties, including temperature, circulation patterns, and nutrient inputs and distributions. These activities in turn can alter biogeochemical processes and fluxes that influence marine foodwebs and ecosystem services, for example the biologically mediated ocean carbon pumps, fisheries, and other renewable marine resources.
These responses of the ocean to changes in anthropogenic forcings will vary with the magnitude and types of impact, ocean region, and foodweb type. The responses may be local or global in scale. Anthropogenic forcing may alter the magnitude and even the direction of services in complex ways, and understanding how marine systems such as carbon pumps will respond to the changing ocean in the anthropocene requires consideration of cumulative effects of multiple activities.
The first step in the carbon pump process is the transfer of atmospheric CO2 into the ocean, where it is taken up by phytoplankton, before organic carbon is synthesized, a portion of which is transferred to pelagic and benthic foodwebs (a regional ecosystem service). Some of the organic carbon can be sequestered in the deep ocean or sediments after being exported from the surface, or by transformation into long-lived dissolved organic compounds (a global ecosystem service). Marine carbon export and sequestration currently makes up about 50% of the anthropogenic CO2 and is hence among the most important earth-ecosystem services provided by the oceans. Biologically mediated carbon cycles also support other important ecosystem services such as aquaculture and fisheries which may also be altered.
This session invites contributions from researchers who use observational, experimental, and modeling approaches to characterize and assess the effects of changing ocean biogeochemical processes and fluxes on the biologically mediated ocean carbon pumps and other ecosystems services, including fisheries and other renewable marine resources.
The topic of this proposed theme session addresses the main focus of the joint PICES/ICES Working Group on Climate Change and Biologically-Driven Ocean Carbon Sequestration.