English
norskBlar i forfatter "Gjøsæter, Harald"
Viser treff 1-11 av 11
-
Acoustic scattering layers reveal a faunal connection across the Fram Strait
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-15)Acoustic scattering layers (SL) at various depths are common phenomena in most oceans, but the organisms that make up these layers vary and so does their density, and hence the backscattered energy. During two crossings of the deep Fram Strait between the shelves at Svalbard and Northeast Greenland at latitudes 77°N and 79°N, we registered epipelagic and mesopelagic SL across the entire Fram Strait ... -
Arctic Fisheries Working Group (AFWG; outputs from 2022 meeting)
(Research report; Forskningsrapport, 2023-03-03)On 30th March 2022, all Russian participation in ICES was suspended. Although the announcement of the suspension stressed the role of ICES as a “multilateral science organization”, this suspension applied not only to research activities but also to the ICES work providing fisheries advice for the sustainable management of fish stocks and ecosystems. As a result of the suspension, it is not possible ... -
The circumpolar impacts of climate change and anthropogenic stressors on Arctic cod (Boreogadus saida) and its ecosystem
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-08)Arctic cod biomass are predicted. In most Arctic seas, the relative abundance of Arctic cod within the fish community will likely fluctuate in accordance with cold and warm periods. A reduced abundance of Arctic cod will negatively affect the abundance, distribution, and physiological condition of certain predators, whereas some predators will successfully adapt to a more boreal diet. Regional ... -
Distribution of rorquals and Atlantic cod in relation to their prey in the Norwegian high Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-14)Recent warming in the Barents Sea has led to changes in the spatial distribution of both zooplankton and fish, with boreal communities expanding northwards. A similar northward expansion has been observed in several rorqual species that migrate into northern waters to take advantage of high summer productivity, hence feeding opportunities. Based on ecosystem surveys conducted during August–September ... -
Fish assemblages at the Yermak Plateau and in northern Svalbard waters during the period 2012–2020
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-20)During several surveys covering the north-western and northern Svalbard waters, and the deeper Yermak Plateau north of Svalbard during the period 2012–2020, 291 standardized hauls with a demersal trawl were made. All fishes in the catches were identified to the lowest possible taxonomic level, mostly to species. In addition to the data generated from the trawl catches, bottom temperature, salinity, ... -
Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-28)In September 2016, a marine ecosystem survey covered all trophic levels from phytoplankton to seals in the Arctic Ocean to the west and north of Svalbard. At the ice edge, 26 harp seals were sampled to assess whether recent environmental changes had affected their diets and body condition by comparing our current results with previous investigations conducted 2–3 decades ago in the northern Barents ... -
The major threats to Atlantic salmon in Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-03)Atlantic salmon (Salmo salar) is an economically and culturally important species. Norway has more than 400 watercourses with Atlantic salmon and supports a large proportion of the world’s wild Atlantic salmon. Atlantic salmon are structured into numerous genetically differentiated populations, and are therefore managed at the population level. Long-distance migrations between freshwater and ocean ... -
Predation on early life stages is decisive for year-class strength in the Barents Sea capelin (Mallotus villosus) stock
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-11)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 ... -
Productive detours – Atlantic water inflow and acoustic backscatter in the major troughs along the Svalbard shelf
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-30)Atlantic Water (AW) flowing along the western and northern Svalbard shelf-break extends the Atlantic domain into the Arctic and is the region’s major source of heat, nutrients and advected plankton. We investigated the inflow and recirculation of AW into four major troughs that cut into the Svalbard shelf, the Isfjorden, Kongsfjorden, Hinlopen and Kvitøya Troughs, and related the circulation patterns ... -
Spatial and temporal changes in the Barents Sea pelagic compartment during the recent warming
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-11)The Barents Sea has experienced substantial warming over the last few decades with expansion of relatively warm Atlantic water and reduction in sea ice. Based on a review of relevant literature and additional analyses, we report changes in the pelagic compartment associated with this warming using data from autumn surveys (acoustic capelin, 0-group fish, and ecosystem surveys). We estimated ... -
Under-ice observations by trawls and multi-frequency acoustics in the Central Arctic Ocean reveals abundance and composition of pelagic fauna
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-18)The rapid ongoing changes in the Central Arctic Ocean call for baseline information on the pelagic fauna. However, sampling for motile organisms which easily escape vertically towed nets is challenging. Here, we report the species composition and catch weight of pelagic fishes and larger zooplankton from 12 trawl hauls conducted in ice covered waters in the Central Arctic Ocean beyond the continental ...
