ICES/PICES/PAME Working Group on Integrated Ecosystem Assessment (IEA) for the Central Arctic Ocean (WGICA)

The Working Group on the Integrated Assessment of the Central Arctic Ocean (WGICA) aims to provide a holistic analysis of the present and future status of the ecosystem and human activities therein. Data collection in the Central Arctic Ocean (CAO) has been inconsistent both spatially and temporally, which can limit the ability to conduct comprehensive analyses of trends and warning signals. However, coverage of data collection has been improving over the past few years. WGICA collates and analyses this regional information, which will be used to help guide the production of an Ecosystem Overview (EO) that relates the main regional pressures in the CAO with the human activities and the ecosystem components that are most impacted by these pressures.Climate change reduces sea ice, increases light penetration, causes regionally variable trends in stratification and mixing of the water column, increases inflow in both the Atlantic and Pacific sectors, and heating of waters at the surface and extending deeper and deeper. These changes in turn affect primary production and cascade through the food web to ice-associated fauna, zoo-plankton, fish, benthos, and sea mammals.These changes may be exacerbated by increasing human activities in and around the CAO, in-cluding increasing pollution from ship traffic and from the transport of contaminants to the ecoregion by rivers and ocean currents. The number of ships and distances traveled are increas-ing and it is anticipated that both commercial and tourist traffic by sea and air will continue to rise. The CAO has become an important sink for many pollutants such as microplastics, which have been found in sea ice and wildlife. Current and future threats to the ecoregion from these activities also include increased risk of oil spills and biodiversity loss if ocean mining expands into the Arctic.While an agreement has been made to ban commercial fishing in the high seas of the Central Arctic Ocean; fish populations continue to be impacted by the effects of a warming ocean, re-treating ice-cover and acidification. These threats have important ecological and policy implica-tions for the entire food web and the Arctic community. For example, negative impacts on the polar cod population will negatively impact ringed seals and beluga whales and therefore will also affect subsistence harvests in the future.In upcoming years, WGICA plans to further define and describe human activities and resulting pressures and related management organizations, and develop a climate and vulnerability as-sessment of the CAO.