Bentiske makroinvertebrater i littoralsonen av innsjøer utgjør en stor del av innsjøers økosystem, og samfunnsstrukturen av disse dyrene kan være med å påvirke hele økosystemet. Forskjellige arter av bunndyr har forskjellige livssykluser og tilpasninger til habitatene de lever i og det er rimelig å forvente at sammensetningen av arter endrer seg med forskjellige dyp og bunnsubstrat, og også over ...

Salmon lice are parasitic copepods with three planktonic larvae stages, consisting of two nauplii stages and a copepodite stage. The parasite spread during these stages as plankton, and with the increased number of host represented by salmonid fish in aquaculture it is important to know the concentrations and ecology of the fee-living stages. Both Lepeophtheirus salmonis and Caligus elongatus are ...

The importance of landfast ice as a nursery and breeding ground for Arctic marine invertebrates was studied in Van Mijenfjorden (77°N, 15/16°W), southwestern Svalbard from March to May 2017. The collection of first-year ice cores with stations along a depth gradient allowed the investigation of both temporal and spatial differences in sympagic meiofauna community composition and abundance. Furthermore, ...

The vast majority of studies in northern lake systems have been carried out on a short-term scale, principally during spring and summer and mostly focusing on a single parasite species. There are few winter studies of fish parasites in the subarctic area, and even less regarding seasonal variations in the sub-communities of intestinal parasites in Arctic charr (Salvelinus alpinus) and brown trout ...

The Seasonal population dynamics of the small copepod species Oithona similis (cyclopoida), Microsotella norvegica (harpacticoida) and Microcalanus spp. were investigated in the northern Norwegian fjords Balsfjord, Altafjord and Porsangerfjord. In this study a WP-2 net with 64 µm mesh size was used to sample all the stages of O. similis, M. norvegica and Microcalanus spp. Copepodite stages CI – CVI ...

The Barents Sea is an inflow shelf sea in the Arctic Ocean which experiences climate change consequently reduction in the sea ice extent thereby significantly impacting its ecological importance. This study investigates seasonal variations in the vertical flux of particulate matter including both particulate organic matter (chl a) and particulate inorganic matterin the form of CaCO3 contributed by ...

Studies based on satellite-tracking show that hooded seals (Cystophora cristata) spend many months out in the open sea each year. When the seals are out in the open sea they have no access to fresh water. Experimental studies have showed that hooded seals drink seawater and that they have the capacity to produce urine with Na+ and cl- concentrations equal to or higher than that of seawater. They ...

Sjørøye og sjøørret er anadrome fisker som vandrer mellom ferskvann og sjøvann. Det meste av kunnskapen om vandringsadferden på disse fiskene er gjort på bestander som har tilgang til innsjøer i ferskvannssystemet, i tillegg til at studiene ofte er relativt kortvarige undersøkelser som ikke strekker seg over et helt år. Kunnskapen om anadrome elvelevende bestander er til forskjell mangelfull, spesielt ...

The Barents Sea (BS) is an arcto-boreal sea and one of the most productive areas adjacent to the Arctic, hosting many commercial fish stocks. As a result of climate change, temperature increases and a northward movement of several fish species in the BS have been reported, which will likely change community structures and ecosystem functioning. Hence, more information on ecosystem functioning need ...

Arctic soil microbiomes may have to face drastic climate changes in the coming century. Currently, the arctic tundra act as a carbon sink due to slow decomposition rates of soil organic carbon, which partly owes to low temperatures and poor water drainage. However, with elevated temperatures, large, latent carbon pools stored in arctic permafrost are exposed to mineralization by the active layer ...