The Black-legged Kittiwake Rissa tridactyla population is declining throughout its North Atlantic range. In Norway, the species is classified as Endangered on the Norwegian Red List. Studies of diet are one important requirement for effective management of any species. Because it is easier to sample, chick diet has often been considered a proxy for adult diet in many seabird studies, but the ...

We compared stock origin, size- and age-distributions, and length growth rates derived from Atlantic cod otoliths from archaeological excavations at two sites in northern Norway: Vágar in Lofoten (68◦12 N, ad 1156–1285) and the Værbukta site (70◦57 N, ad 1450–1680). For comparison, modern otoliths were sampled during 1993–2001 from areas situated close to Vágar and Værbukta. Length-at-age from ...

The trophic position concept is central in system ecology, and in this study, trophic position (TP) estimates from stable-isotopes and an Ecopath mass-balance food web model for the Barents Sea were compared. Two alternative models for estimating TP from stable isotopes, with fixed or scaled trophic fractionation were applied. The massbalance model was parametrized and balanced for year 2000, was ...

Large offshore and small inshore populations of Atlantic cod Gadus morhua L. display differences in migratory patterns and settling regimes, but little is known about possible differences in spawning behaviour. Cod presumably of the Norwegian coastal cod type were therefore sampled during 7 spawning seasons (2002-2013) in Malangen, northern Norway. A spawning site in neighbouring Balsfjord was sampled ...

Utviklingen av havbruksnæringen styres etter prinsippet om bærekraftig utvikling; sosial, økonomisk og miljømessig. Forvaltningen trenger mer kunnskap om hvilke effekter merdbasert havbruk har på økosystemtjenester og samfunn. Balsfjorden gir en unik mulighet til å studere hvordan anleggsetablering påvirker miljø og samfunn, der status for systemet i stor grad er kjent før etablering, og det kan ...

The invasive red king crab Paralithodes camtschaticus preys on lumpsucker Cyclopterus lumpus eggs. We tested the hypothesis this egg consumption may hamper the recruitment of lumpsucker. Methods applied included field work, laboratory experiments and modelling of egg consumption. Crabs were sampled and feeding behaviour was studied by means of a remotely operated vehicle and SCUBA divers in a field ...

We built a dynamic, spatial food web model for the Barents Sea, developed with Ecospace by including species’ habitat requirements and ecological interactions. The model was used to test the spatial shifts of different functional groups due to warming. We compared model-predicted and field-surveyed biomass of functional groups (FGs) spatial distributions in relatively cold and warm years. The ...

The Barents Sea (BS) is a high-latitude shelf ecosystem with important fisheries, high and historically variable harvesting pressure, and ongoing high variability in climatic conditions. To quantify carbon flow pathways and assess if changes in harvesting intensity and climate variability have affected the BS ecosystem, we modeled the ecosystem for the period 1950–2013 using a highly trophically ...

Year-class strength of Barents Sea capelin has been monitored closely since the early 1970s and during this ∼45 years period three short periods of almost total recruitment failure leading to three stock collapses have been observed. These events triggered much attention since there was a large commercial fishery for capelin, but also because of observed ecosystem effects attributed to the first of ...

We sampled 0-group juvenile Atlantic cod Gadus morhua L. within fjords and offshore in northern Norway from 1994 to 2008 using different gears for the 3 sampling depths: shore seine (0−3 m), pelagic trawl (various depths), and bottom trawl (>80 m). Frequencies of alleles at the Pan I locus (4218 fish analysed) showed highly significant differences among samples collected in the different habitats. ...