Reindeer (<i>Rangifer tarandus</i>) are host to gastrointestinal-tract nematodes (GINs) throughout the world. Some populations of reindeer exist in almost complete isolation from others, and this can have a key influence on the species and infection rates of GINs. An example of an isolated reindeer population occurs in Iceland. In this study, I have investigated the prevalence of GINs in Icelandic ...

Deep-sea sharks are little resilient to targeted harvesting and bycatch fisheries due to their life history strategy characterized by slow growth, late sexual maturity, low fecundity, and few offspring. The Northeast Atlantic component of Etmopterus spinax is an example of a species where substantial population changes in terms of abundances have occurred due to intensive fisheries induced mortality. ...

Som følge av at norske laksebestander har blitt redusert i løpet av de siste tiårene har det blitt vanligere å gjenutsette laks i forbindelse med sportsfiske. Noen av disse gjenutsatte laksene er rapportert å gjenfanges, men omfanget av dette har hittil ikke vært dokumentert i detalj i norske elver. Slik gjenfangst kan tenkes å beskatte forskjellige deler av en populasjon ulikt, være problematisk i ...

Cod aquaculture is a rapidly expanding industry in Norway and with an increase of biomass in mariculture the concern for diseases spread to and from farmed populations of cod is increasing. The genus Gyrodactylus Nordmann, 1832 are parasitic monogeneans infecting teleost fish in marine and fresh water habitats worldwide. To investigate a possible problematic species of this genus the gill filaments ...

Fjæreplytt (Calidris maritima) er verdens nordligste overvintrende vader og oppholder seg gruppevis i fjæresonen i Tromsøområdet gjennom vinteren. En flokk fjæreplytt ble observert å konsekvent bytte beitehabitat mellom dag og natt. Ved hjelp av radiosendere og individuelle ringmerker ble natthabitat avdekket og flokken verifisert som den samme i begge habitat. For å undersøke hva som kunne styre ...

Hibernation is a physiological and behavioural adaptation that permits survival during seasonal periods of energy shortage via a combination of pre-hibernal energy storage and hibernal metabolic depression, i.e. torpor. The central mechanisms in the brain that control torpor expression and arousal from it has been under investigation since the dawn of hibernation research but remains unknown. Recent ...

Plant-soil feedbacks receive increasing attention as impactors of plant performance and drivers of plant community composition. How plant-soil feedbacks act in introduction events regarding both native and foreign species is a topic requiring more research. In this aspect, two particular theories are of interest, Home-field advantage, and Enemy-release. The former predicts that plants perform best ...

In the last nine winters, a humpback whale feeding aggregation has been observed in the nearshore waters and fjords of northern Norway. This seasonal humpback whale occurrence is presumably driven by a shift in the overwintering distribution of Norwegian spring spawning (NSS) herring into these coastal areas. Eastern North Atlantic humpback whales feed during summer in relative remote regions in ...

Current knowledge of the Arctic marine ecosystem is based primarily on studies performed during the polar day on the pelagic and benthic realms. Both the polar night and the hyperbenthic layer remain substantial knowledge gaps in the understanding of the marine system at high latitudes. To help address these knowledge gaps, this project investigates the hyperbenthic food web structure in Kongsfjord, ...

Polyploidization can be a rapid path to speciation and is considered an important evolutionary mechanism. Some predict that all plants have undergone a polyploidization event during their evolutionary history, and the frequency of polyploid species increases with latitude. The Arctic-Alpine Saxifraga oppositifolia, an autopolyploid, has two polyploids that have successfully established themselves ...