Blar i Brage IMR på forfatter "Ottersen, Geir"
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IMR status report on the Barents Sea Ecosystem, 2004-2005
Stiansen, Jan Erik; Bogstad, Bjarte; Dalpadado, Padmini; Gjøsæter, Harald; Hauge, Kjellrun Hiis; Ingvaldsen, Randi; Loeng, Harald; Mauritzen, Mette; Mehl, Sigbjørn; Ottersen, Geir; Stenevik, Erling Kåre (Working paper, 2005) -
Including climate into the assessment of future fish recruitment, using multiple regression models.
Stiansen, Jan Erik; Aglen, Asgeir; Bogstad, Bjarte; Loeng, Harald; Mehl, Sigbjørn; Nakken, Odd; Ottersen, Geir; Svendsen, Einar (ICES CM documents, Working paper, 2005)Climate variability has generally not been included in the assessment of fish stocks in the Barents Sea and Norwegian Sea. However, in recent years there has been a focus on implementing climate variability in the assessment ... -
Indirect climatic forcing of the Barents Sea capelin: a cohort effect
Hjermann, Dag Ø.; Stenseth, Nils Christian; Ottersen, Geir (Journal article; Peer reviewed, 2004-06-08)Planktivorous capelin is a key species in the Barents Sea, being of great importance in the exploitation of plankton production in this subarctic region. However, in years with a successful reproduction of the Norwegian ... -
Inter-regional comparison of climate effects on marine fish populations facilitated through classification of mechanisms
Ottersen, Geir; Stenseth, Nils Christian (ICES CM documents;2007/D:17, Working paper, 2007)Variations in climate strongly affect the structure and function of marine ecosystems, but a number of different mechanisms are at play and their relative importance varies between regions and with time. There are obvious ... -
Kaldere Barentshav mot år 2000
Loeng, Harald; Ottersen, Geir; Ådlandsvik, Bjørn (Havforskningsnytt, Working paper, 1994) -
Key physical processes and their model representation for projecting climate impacts on subarctic Atlantic net primary production: A synthesis
Myksvoll, Mari Skuggedal; Sandø, Anne Britt; Tjiputra, Jerry; Samuelsen, Annette; Yumruktepe, Veli Caglar; Li, Camille; Mousing, Erik Askov; Bettencourt, Joao P.H.; Ottersen, Geir (Peer reviewed; Journal article, 2023)Oceanic net primary production forms the foundation of marine ecosystems. Understanding the impact of climate change on primary production is therefore critical and we rely on Earth System Models to project future changes. ... -
Landscape dynamics and predator-prey interactions in marine environments
Ciannelli, Lorenzo; Bailey, Kevin; Frank, Kenneth T.; Hjermann, Dag Ø.; Ottersen, Geir; Stenseth, Nils Christian (ICES CM documents, Working paper, 2004)In several sub-arctic marine ecosystems of the North Atlantic capelin are the primary prey item for cod, and the trophic interaction between capelin and cod is a central energetic pathway. However, in the North Pacific ... -
Latitudinally distinct stocks of Atlantic cod face fundamentally different biophysical challenges under on-going climate change
Kjesbu, Olav Sigurd; Alix, Maud; Sandø, Anne Britt; Strand, Espen; Wright, Peter J.; Johns, David G.; Thorsen, Anders; Marshall, C. Tara; Bakkeplass, Kjell Gunnar; Vikebø, Frode Bendiksen; Myksvoll, Mari Skuggedal; Ottersen, Geir; Allan, Bridie Jean Marie; Fossheim, Maria; Stiansen, Jan Erik; Huse, Geir; Sundby, Svein (Peer reviewed; Journal article, 2023)The reproductive success of marine ectotherms is especially vulnerable in warming oceans due to alterations in adult physiology, as well as embryonic and larval survival prospects. These vital responses may, however, differ ... -
Latitudinally distinct stocks of Atlantic cod face fundamentally different biophysical challenges under on-going climate change
Kjesbu, Olav Sigurd; Alix, Maud; Sandø, Anne Britt; Strand, Espen; Wright, Peter J.; Johns, David G.; Thorsen, Anders; Marshall, C. Tara; Bakkeplass, Kjell Gunnar; Vikebø, Frode Bendiksen; Myksvoll, Mari Skuggedal; Ottersen, Geir; Allan, Bridie Jean Marie; Fossheim, Maria; Stiansen, Jan Erik; Huse, Geir; Sundby, Svein (Peer reviewed; Journal article, 2023)The reproductive success of marine ectotherms is especially vulnerable in warming oceans due to alterations in adult physiology, as well as embryonic and larval survival prospects. These vital responses may, however, differ ... -
Long-term interplay between harvest regimes and biophysical conditions may lead to persistent changes in age at sexual maturity of Northeast Arctic cod (Gadus morhua)
Carl Jacob, Rørvik; Bogstad, Bjarte; Ottersen, Geir; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2022)This investigation commenced by constructing principal maturation schedule equations as a function of fishing mortality (F), key biophysical factors and a term attributed to fisheries-induced adaptive change (FIAC). Following ... -
Long-term variability in spawning stock age structure influences climate–recruitment link for Barents Sea cod
Ottersen, Geir; Holt, Rebecca Emma (Peer reviewed; Journal article, 2022)Fish populations may spawn a vast number of offspring, while only a small and highly variable fraction of a new cohort survives long enough to enter into the fisheries as recruits. It is intuitive that the size and state ... -
Long-term variability in spawning stock age structure influences climate–recruitment link for Barents Sea cod
Ottersen, Geir; Holt, Rebecca Emma (Peer reviewed; Journal article, 2022)Fish populations may spawn a vast number of offspring, while only a small and highly variable fraction of a new cohort survives long enough to enter into the fisheries as recruits. It is intuitive that the size and state ... -
MILJØVERDIERS SÅRBARHET I NORSKE HAVOMRÅDER — En gjennomgang av sårbarhet til ulike typer påvirkninger i foreslåtte særlig verdifulle og sårbare områder i norske havområder
Hansen, Cecilie; Hjøllo, Solfrid Sætre; Ottersen, Geir; Skern-Mauritzen, Mette (Rapport fra havforskningen;2022 - 33, Research report, 2022)Det er gjennomført en kunnskapsbasert vurdering av sårbarhet med konfidens for de viktigste påvirkninger på miljøverdier i norske havområder generelt, og for hvert av områdene som er foreslått som Særlig verdifulle og ... -
Multiple stakeholders’ perspectives of marine social ecological systems, a case study on the Barents Sea
Mikkelsen, Nina; Planque, Benjamin; Arneberg, Per; Skern-Mauritzen, Mette; Hansen, Cecilie; Fauchald, Per; Holsman, Kirstin K.; Haynie, Alan C.; Ottersen, Geir (Peer reviewed; Journal article, 2023)The Barents Sea ecosystem components and services are under pressure from climate change and other anthropogenic impacts. Following an Ecosystem-based management approach, multiple simultaneous pressures are addressed by ... -
Observed and expected future impacts of climate change on marine environment and ecosystems in the Nordic region
Ottersen, Geir; Børsheim, Knut Yngve; Arneborg, Lars; Maar, Marie; Schourup-Kristensen, Vibe; Rosell, Elin Almroth; Hieronymus, Magnus (Rapport fra havforskningen;2023 - 10, Research report, 2023)The UN's Intergovernmental Panel on Climate Change (IPCC) reports are comprehensive, thorough and important, but they cover the whole world and this is at the expense of scope and precision on a regional scale. Specifically, ... -
Ontogenetic spatial constraints of sub-arctic marine fish species
Ciannelli, Lorenzo; Neuheimer, Anna B.; Stige, Leif Christian; Frank, Kenneth T.; Durant, Joël; Hunsicker, Mary E.; Rogers, Lauren; Porter, Steve; Ottersen, Geir; Yaragina, Natalia A. (Peer reviewed; Journal article, 2021)Marine species may respond and adapt to climate change through shifting spatial distributions, but options may be limited by the occupancy of essential habitats which are anchored in space. Limited knowledge of when spatial ... -
Population dynamics of cod Gadus morhua in the North Sea region: biological density-dependent and climatic density-independent effects
Chen, Qingxian; Chan, Kung-Sik; Lekve, Kyrre; Torstensen, Else; Gjøsæter, Jakob; Ottersen, Geir; Stenseth, Nils Christian (Journal article; Peer reviewed, 2005-11-04)Through the statistical modeling of monitoring data, we assess the ecological interlinkages between cod Gadus morhua L. in the North Sea, Skagerrak and Kattegat—regions which typically have been considered separate management ... -
Productivity in the Barents Sea - Response to Recent Climate Variability
Dalpadado, Padmini; Arrigo, Kevin R.; Hjøllo, Solfrid Sætre; Rey, Francisco; Ingvaldsen, Randi B.; Sperfeld, Erik; Dijken, Gert L. van; Stige, Leif C.; Olsen, Are; Ottersen, Geir (Journal article; Peer reviewed, 2014-05-01)The temporal and spatial dynamics of primary and secondary biomass/production in the Barents Sea since the late 1990s are examined using remote sensing data, observations and a coupled physical-biological model. Field ... -
Pronounced long-term juvenation in the spawning stock of Arcto-Norwegian cod (Gadis morhua) and possible consequences for recruitment
Ottersen, Geir (Journal article; Peer reviewed, 2008-01)The oldest and largest individuals are disappearing from many fish stocks worldwide as a result of overexploitation. This has been suggested to impair recruitment through decreasing the reproductive capacity of the spawners ... -
Samlet påvirkning i foreslåtte særlig verdifulle og sårbare områder i norske havområder
Hansen, Cecilie; Aarflot, Johanna Myrseth; Eriksen, Elena; Husson, Berengere; Fauchald, Per; Johansen, Geir Odd; Jørgensen, Lis Lindal; van der Meeren, Gro Ingleid; Mikkelsen, Nina; Ottersen, Geir; von Quillfeldt, Cecilie; Skern-Mauritzen, Mette (Rapport fra havforskningen;2022 - 46, Research report, 2022)I dette arbeidet er det gjort en vurdering av risiko fra samlet påvirkning med tilhørende usikkerhet for aktive sektorer i norske havområder, for hvert av havområdene Nordsjøen, Norskehavet og Barentshavet, og for hvert ...