According to theory, a male’s reproductive role should predict investment in ejaculate quality, i.e. subordinate males should invest in ejaculate quality to compensate for mating in unfavourable roles, and vice versa for dominant males. The Arctic charr is known to possess fluctuating characteristics of its sperm triggered by rapid changes in social status. The relationship between social status and ...

Citizen science is increasingly used to include in ecological monitoring over the past three decades. Web-based applications or smart phones enable citizens to record observations or experiences at larger temporal and spatial scale and provide opportunities for a larger number of citizens to participate in mapping observations. Citizen science can also be used to record, or map observed and experienced ...

In absence of top predators, the red fox population reaches a higher number of individuals. The increased presence of red fox, as it invades alpine and tundra ecosystems, might have severe and negative consequences on the ecosystem as a whole. In Finnmark, Northern Norway, immense levels of large herbivores due to reindeer herding roam the tundra. The high numbers of reindeer provide resources (as ...

In the Arctic Ocean, biological productivity is largely determined by sea ice, making the seasonal sea ice zone (SSIZ) its most productive region. The current study is a combined investigation of the suspended biomass, vertical export of organic material, and potential retention processes by zooplankton, during a crucial period of bloom development in the Eurasian SSIZ north of Svalbard, where few ...

Abstract Through the last centuries it has become high disturbances and interventions in natural areas, which has forced wildlife to interact with humans. This has led to human-wildlife conflicts (HWC), where animals have become a threat to peoples’ safety or livelihood. These conflicts have often ended with species becoming endangered or extinct globally, including Norway. There are small populations ...

Introductions and invasions of species outside their natural range can have devastating effects on the native species and be a major driver of biodiversity change. When the zooplanktivorous vendace invaded the Pasvik watercourse in the 1990s, it quickly took over the ecological role of the native DR whitefish. In the upper part of the watercourse, DR whitefish was displaced from the pelagic habitat ...

The harbour porpoise is a key predator in Norwegian coastal communities, therefore studying its feeding ecology is important to understand its ecological role and may shed light on the dynamics of Norwegian coastal ecosystems. The diet of 134 harbour porpoises bycaught in Autumn 2016 (n = 61) and Spring 2017 (n = 73) in Norwegian coastal waters and fjords was investigated using both stable isotopes ...

Oral squamous cell carcinoma (OSCC) is an aggressive cancer associated with high mortality rates. The objective of this master project was to test the following hypotheses: (1) transforming growth factor β1 (TGFβ1) activates fibroblasts in vitro and basic fibroblast growth factor (bFGF) deactivates them while both increase fibroblast proliferation in cancer associated fibroblasts (CAFs); (2) the ...

Ecological systems, such as marine ecosystems, are complex adaptive systems in which large scale system properties (e.g., trophic structure, energy flux patterns, etc.) emerge from interactions between ecosystem components or species. This makes them difficult to understand, predict, and model. The Norwegian and Barents Seas support multiple commercial fisheries, including those for herring, cod, ...

Sammendrag DNA-analyse av hår- og ekskrementprøver er en viktig del i overvåkningen av brunbjørn (Ursus arctos) I Norge. En potensielt nyttig prøveinnsamlingsmetode for slik DNA-basert overvåkning er såkalte hårfeller, som består av en innhegning av piggtråd med luktstoff i senter. Fellene fungerer ved at hår fra bjørnen setter seg fast i piggtråden når bjørnen passerer for å komme inn til ...