Dynamics of legacy and emerging pollutants in fjord ecosystems of the high Arctic: Svalbard (Norway) and NE Greenland

Introduction: Recent climate changes are much faster than previous long-term ones, causing stress on polar marine ecosystems resulting in changes in atmosphere/ocean exchanges, ocean properties, sea ice cover and thickness. These phenomena, associated to anthropogenic emissions, are triggering shifts in global biogeochemical cycles and marine ecosystem. Consequently, ecosystems are rapidly changing. The polar oceans are the final sink for many semi-volatile organic contaminants, which thanks to the atmospheric transport and to the cold condensation concentrate in these areas. The decrease of sea ice, as well as the presence of snow and the mechanism of ice formation/melting, can have a big impact on the carbon cycle, on the mobility of contaminants and on biodiversity loss. Moreover, the list of chemicals found in arctic ecosystems continuous to grow and increasing temporal trends have been reported for some current-use chemicals. The study of the composition of dissolved organic carbon (DOC) and the occurrence of organic contaminants together with the biodegradation capability of natural microbial communities, is of strategic importance to describe the circulation of nutrients and the impact of allochthones sources on the marine ecosystem. Anthropogenic impacts can change the quality of the natural DOC, with repercussions on the spread, persistence and bioavailability of allochthonous organic matter, including the fate and the toxic effects exerted by some persistent organic pollutants (POPs). Contaminant global transport (POP, http://chm.pops.int) could also be affected by climate change and it is essential adding new elements to study potential biotic repercussions of synergistic effects between long-slow global stressors (e.g., increasing temperature due to climate change) and short-rapid local stressors (e.g., contaminants and coastal hypoxia). The aim of this study was: (I) evaluating the dynamics of contaminants in the high Artic fjord ecosystem. The concentration of pollutants of environmental concern (PAHs, NPs and BPA, POPs, PCBs, CUPs, PFAs, others) will be studied in sediment and seawater. (II) Characterizing the DOC in the water column by ultrafiltration tangential-flow techniques according to the size fractions (colloidal and truly dissolved) to evaluate if the transport of contaminants is affected by DOC dimensions. (III) Investigating the potential links occurring between ecosystem contamination and metabolic processes mediated by the resident microbial communities.