Atlantic salmon is an economically and culturally important species. The species encounters several natural and man-made threats during its migration between fresh water and the ocean, which in combination may explain its ongoing decline. With the aim to better understand whether post-smolt behaviour is influenced by physical oceanographic conditions, the migratory behaviour of 173 post-smolts in a ...

This work summarizes ice algal studies, presented as biomass and species temporal and spatial distribution, during 11 cruises conducted between 1986 and 2012. The majority of the biomass was found as loosely attached sub-ice algal layers, and sampling required diving. A maximum of 40 mg chlorophyll m⁻² and 15.4 × 10⁹ cells m⁻² was measured in May. The species ...

The rate of ocean-driven retreat of Greenland’s tidewater glaciers remains highly uncertain in predictions of future sea level rise, in part due to poorly constrained glacier-adjacent water properties. Icebergs and their meltwater contributions are likely important modifiers of fjord water properties, yet their effect is poorly understood. Here, we use a 3-D ocean circulation model, coupled to ...

Phenotypic polymorphism is a commonly observed phenomenon in nature, but extremely rare in free-living stages of parasites. We describe a unique case of somatic polymorphism in conspecific cercariae of the bird schistosome Trichobilharzia sp. “peregra”, in which two morphs, conspicuously different in their size, were released from a single Radix balthica snail. A detailed morphometric analysis ...

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October ...

Arctic cod (Boreogadus saida) strongly dominates the ichthyoplankton assemblages of High Arctic seas, hence competition with other native species seldom has been studied. Yet, interspecific competition could negatively impact the survival of early life stages of fishes in Arctic areas where higher diversity prevails. We surveyed the ichthyoplankton community of the Greenland Sea, in August–September ...

There has been a considerable number of reports on Hg concentrations in Arctic mammals since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of the exposure to mercury (Hg) in Arctic biota in 2010 and 2018. Here, we provide an update on the state of the knowledge of health risk associated with Hg concentrations in Arctic marine and terrestrial mammal ...

Atlantic salmon post-spawners from a population in northern Norway were tagged with data storage tags (N = 773), and the depth use and diving behaviour of recaptured individuals within the coastal zone were examined, both on their outward migration to sea (N = 44) and their return to the natal river after overwintering at sea (N = 34). In addition, the stomach contents of 909 returning adults caught ...

Long-term data are critically important to science, management, and policy formation. Here we describe a number of data collections from arctic Canada that monitor vertebrate population trends of freshwater and marine fish, marine birds, marine and terrestrial mammals. These time series data cover the last ca. 30 years and capture a period from the onset of global changes affecting the Arctic up to ...

Climate and land-use changes are leading to impacts on individual ecosystems as well as shifts in transfer dynamics between interconnected systems. At the land-ocean interface, changes in riverine inputs of organic matter (OM) and nutrients have the potential to lead to shifts in coastal carbon and nutrient cycling with consequences for ecosystem structure and function. In this study, we assess OM ...