The diet of polar bears in the Svalbard area was assessed based analyses of scats (n=119) collected in the Archipelago between 2003 and 2010. Most of the samples were collected in spring. Morphological analysis of the prey remains together with genetic analyses of tissue fragments found in the scats showed that ringed seals (Pusa hispida) were the most important prey group present; this seal species ...

Pasvikvassdraget ble tidlig på 1990-tallet utsatt for en invasjon av lagesild fra Enaresjøen i Finland. I 2009 ble det gjennomført et eksperiment med utsetting av 1500 ørret i Ruskebukta i øvre del av vassdraget, for å undersøke ørretens egnethet til biokontroll av den invaderende lagesilda. For at biokontroll med fiskespisende ørret skal være vellykket er det viktig å ha god kjennskap til økosystemet ...

Ressursdeling og ontogenetisk nisjeskift ble undersøkt hos sympatrisk ørret og røye ved å inkludere stabile karbon- og nitrogenisotoper for å få et mer langtidsintegrert bilde av fiskens næringshabitat og diettbruk. I begge innsjøene benyttet ørreten seg primært av littoralsonen, mens røya tok i bruk alle tilgjengelige habitater. Det ble funnet en tydelig ressursdeling i diett mellom ørret og ...

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 ...

Estimates of repeatability (R) are an important statistic tool in assessing the consistency of individual differences and thus different phenotypes. A high repeatability of estimates of the daily energy expenditure (DEE), allow for better inferences of the long term energetic effort of individuals, as well as for sound correlations of other traits related to individual performance, such as reproductive ...

In today’s society, one often stumbles over the quote “you are what you eat”. Diet is closely related to fish size and physical conditions, so in order to understand the food web one must first understand the population dynamics of the fish. Three demersal species in the northern hemisphere are; Artediellus atlanticus, Myoxocephalus scorpius and Leptagonus decagonus. The study was undertaken in ...

Microbial fermentation in the world domesticated ruminant populations is thought to be responsible for as much as 13.5-33% of the global anthropogenic methane (CH4) emissions (World Resources Institute 2005, EPA 2004, Bodas et al., 2012). However, methane also represents a loss of 2-15% of the gross energy intake in these animals (Blaxter and Clapperton 1965, Holter and Young 1992, Johnson and Ward ...

Sympatric occurring fish morphs in postglacial lakes usually exhibit differences in morphology and physiology driven by adaptations to differential trophic niches. The European whitefish (Coregonus lavaretus (L.)) is a highly variable fish species, with more than 200 intraspecific forms described in Europe. The morphs usually differ in their number of gill-rakers, therefore this trait has been ...

For hundreds of years arctic foxes on the Svalbard archipelago have been hunted and trapped for their warm and attractive fur. However, little is known about the effect that trapping has on this species population structure. Here I assess the effect of trapping on arctic foxes by comparing the demographic and genetic structure of foxes from the Austfjordnes area in Svalbard over three consecutive ...

Silicate-rich grasses often dominate in heavily grazed areas, presumably because high amounts of silica deter herbivores. Activity of large herbivores and small rodent herbivores increase competitive ability of silicate-rich grasses, possibly through apparent competition. Both types of herbivores often co-exist in grassland ecosystems. Their potential additive effect on competitive ability of ...