Barents Sea capelin (Mallotus villosus) year class strength is thought to be determined during the first months after egg hatching. The now widely accepted Hamre’s hypothesis states that young herring (Clupea harengus) present in the southern Barents Sea potentially may cause poor capelin recruitment. This hypothesis was presently tested through model scenarios, by simulating a realistic spatio-temporal ...

The Polar Front separating Atlantic Water (AW) and Arctic Water (ArW) is one of the most dominant mesoscale features in the Barents Sea and a highly productive region. Here, the results of sub-mesoscale variability in physical and biological fields associated with the Barents Sea Polar Front (BSPF) at the Great Bank are reported from a high-resolution survey in August 2007. A nearly synoptic data ...

The pineal gland is part of the endocrine system involved with rhythmic activity in e.g. fish. The main product of the pineal gland is the indole hormone melatonin, synthesised from the amino acid tryptophan. Melatonin is mainly synthesized when it is dark, as light inhibit the production. For this reason melatonin is thought to be strongly involved in biological rhythms. Arctic charr (Salvelinus ...

Tetthetsavhengig næringsmangel som fører til lave vekter og påfølgende minket rekruttering er et velkjent fenomen i reindriften i Finnmark. Forskjeller i vekt og produksjon i reindriften i Norge har blitt forklart med ulikheter i høstingsstrategier og vinterforhold. Imidlertid har det blitt viet mindre oppmerksomhet til hvordan ulike sommerbeiteforhold påvirker reproduksjon og vektutvikling. I dette ...

Lumpsucker (Cyclopterus lumpus) is a demersal and shallow water spawning fish species with a relatively long egg incubation period. In case of acute oil pollution the embryos will be exposed to PAHs in the water for a relative long period. In this experiment we made a flow through rock column incubation system with oil contaminated gravel and exposed fertilized lumpsucker eggs to the water soluble ...

Formålet med denne oppgaven var å se på kvantitative endringer av makroalge- og lavsamfunnet i littoralsonen på fem lokaliteter i Troms, langs en eksponeringsgradient fra fjord til kyst. Ofte finner man samfunnsendringer innover i fjordene som er nært korrelert med forandringer i substratets stabilitet, tekstur og lokaltopografiske forhold i fjæra (helning) (pers. med. Tor Eiliv Lein). Artsdiversiteten ...

Anthropogenic and natural stressors can affect ecosystems negatively and it is therefore important to have a clear understanding of the responses of organisms to stressors. The Northern Goshawk (Accipiter gentilis) is a common raptor species of the boreal forest ecosystem and its location at the top of its food chain makes it a special target for two important stressors; endoparasitism and environmental ...

The female Common eider (Somateria mollossima) is a drab, lightly coloured bird, easily distinguished from the brightly ornamented male. Unlike the male, the female has white bands on the tips of her wings, and these white wing bands have been shown to reflect individual quality in previous studies. In this study the potential role of the white wing bands in parental care and mate choice is studied, ...

Marine copepods of the genus Pseudocalanus (Calanoida) are common in Svalbard waters as well as throughout the northern hemisphere. They contribute considerably to plankton biomass in addition to Calanus spp. and play an important role in the marine food web as a link between planktivores, such as fish larvae, and microalgae. Pseudocalanus consists of several sibling species, and two of them, ...

Most studies of nest site selection by northern goshawk, Accipiter gentilis, have been done in mixed – or coniferous forests, and emphasis has been put on the importance of large trees and relatively intact, old forest stands for nesting sites. However, goshawks in northern Norway are found in birch forests characterized by relatively small trees and a high natural level of fragmentation. In this ...