Understanding the present state and possible future scenarios of Arctic Ocean primary productivity has been hampered by the scarcity of year-round nutrient measurements. Here, the first year-long moored timeseries of near-surface nitrate concentrations in the Eastern Arctic, together with hydrography, currents and chlorophyll-a fluorescence, is reported from ...

During the N-ICE2015 drift expedition north-west of Svalbard, we observed the establishment and development of algal communities in first-year ice (FYI) ridges and at the snow-ice interface. Despite some indications of being hot spots for biological activity, ridges are under-studied largely because they are complex structures that are difficult to sample. Snow infiltration communities can grow at ...

Knowledge of the complete horizontal migration and vertical movements of Atlantic salmon (Salmo salar L.) during the marine phase is important for understanding the link between individual processes and population recruitment. We studied the detailed migration behaviour of six post-spawned adult Atlantic salmon from a North Norwegian river, during the entire ocean migration, by using high-resolution ...

Climate change is occurring across the world, with effects varying by ecosystem and region but already occurring quickly in high-latitude and high-altitude regions. Biotic interactions are important in determining ecosystem response to such changes, but few studies have been long- term in nature, especially in the High Arctic. Mesic tundra plots on Svalbard, Norway, were subjected to grazing at ...

The effect of variable autumn temperatures in combination with decreasing irradiance and daylength on photosynthesis, growth cessation and freezing tolerance was investigated in northern- and southern3 adapted populations of perennial ryegrass (Lolium perenne L.) and timothy (Phleum pratense L.) intended for use in regions at northern high latitudes. Plants were subjected to three different acclimation ...

Benthic invertebrate communities play a fundamental role in lake ecosystems, and the understanding of how those benthic communities are structured, particularly in terms of the identity and spatiotemporal distribution of their functional traits, is key to our understanding of how lake ecosystems work. In Takvatn, a subarctic lake in northern Norway, we identified the taxonomic and functional identity ...

<b>Background:</b> Brucellosis is the most common zoonotic infections in pastoral settings. Lack of knowledge about the disease may cause devastating out come to the patients, thus sustained it in such communities. This study assessed knowledge and practices among high-risk groups in Bahr el Ghazal region, South Sudan. <br><b>Methods:</b> Across sectional survey involving abattoir workers, febrile ...

Résumé : L’étude fait état de preuves empiriques appuyant le paradigme de « croissance–survie » chez les phases marines de l’omble chevalier (Salvelinus alpinus) et de la truite de mer (Salmo trutta). Ce paradigme postule que les individus plus grands ou a` croissance plus rapide sont plus susceptibles de survivre que leurs conspécifiques plus petits ou a` croissance plus lente. Nous avons utilisé ...

It is important that climate models can accurately simulate the terrestrial carbon cycle in the Arctic due to the large and potentially labile carbon stocks found in permafrost-affected environments, which can lead to a positive climate feedback, along with the possibility of future carbon sinks from northward expansion of vegetation under climate warming. Here we evaluate the simulation of tundra ...

Planktonic copepods of the genus Calanus play a central role in North Atlantic/Arctic marine food webs. Here, using molecular markers, we redrew the distributional ranges of Calanus species inhabiting the North Atlantic and Arctic Oceans and revealed much wider and more broadly overlapping distributions than previously described. The Arctic shelf species, C. glacialis, dominated the zooplankton ...