Blar i Brage IMR på forfatter "Johnsen, Espen"

Viser treff 21-40 av 41

    • Highly mixed impacts of near-future climate change on stock productivity proxies in the North East Atlantic 

      Kjesbu, Olav Sigurd; Sundby, Svein; Sandø, Anne Britt; Alix, Maud; Hjøllo, Solfrid Sætre; Tiedemann, Maik; Skern-Mauritzen, Mette; Junge, Claudia; Fossheim, Maria; Broms, Cecilie; Søvik, Guldborg; Zimmermann, Fabian; Nedreaas, Kjell Harald; Eriksen, Elena; Höffle, Hannes; Hjelset, Ann Merete; Kvamme, Cecilie; Reecht, Yves; Knutsen, Halvor; Aglen, Asgeir; Albert, Ole Thomas; Berg, Erik; Bogstad, Bjarte; Durif, Caroline; Halvorsen, Kim Aleksander Tallaksen; Høines, Åge Sigurd; Hvingel, Carsten; Johannesen, Edda; Johnsen, Espen; Moland, Even; Myksvoll, Mari Skuggedal; Nøttestad, Leif; Olsen, Erik Joel Steinar; Skaret, Georg; Skjæraasen, Jon Egil; Slotte, Aril; Staby, Arved; Stenevik, Erling Kåre; Stiansen, Jan Erik; Stiasny, Martina H.; Sundet, Jan Henry; Vikebø, Frode Bendiksen; Huse, Geir (Peer reviewed; Journal article, 2021)
      Impacts of climate change on ocean productivity sustaining world fisheries are predominantly negative but vary greatly among regions. We assessed how 39 fisheries resources—ranging from data-poor to data-rich stocks—in the ...

    • In situ calibration of observatory broadband echosounders 

      Ona, Egil; Zhang, Guosong; Pedersen, Geir; Johnsen, Espen (Peer reviewed; Journal article, 2020)
      Today, numerous scientific echosounders are used as continuously monitoring systems in ocean observatories. These echosounders are usually calibrated in shallow water, either in laboratory tanks or at random ocean docks ...

    • Kayak Drone – a silent acoustic unmanned surface vehicle for marine research 

      Totland, Atle; Johnsen, Espen (Peer reviewed; Journal article, 2022)
      Advancements in technologies have led to a rapid development of unmanned surface vehicles (USV) for marine ecosystem monitoring. The design, size, and scientific payload of the USVs differ as they are built for different ...

    • Kunnskapsstatus for havsil i norsk sone av Nordsjøen 

      Johnsen, Espen; Sørhus, Elin; de Jong, Karen; Lie, Kai Kristoffer; Grøsvik, Bjørn Einar (Rapport fra havforskningen;2021 - 33, Research report, 2021)
      Tobis eller havsil er en nøkkelart i økosystemet i Nordsjøen, og viktige gyte- og leveområder for havsil er identifisert som særlig verdifulle og sårbare områder (SVO) i Nordsjøen. Rapporten oppsummerer eksisterende kunnskap ...

    • Magnetic fields generated by the DC cables of offshore wind farms have no effect on spatial distribution or swimming behavior of lesser sandeel larvae (Ammodytes marinus) 

      Cresci, Alessandro; Perrichon, Prescilla; Durif, Caroline; Sørhus, Elin; Johnsen, Espen; Bjelland, Reidun Marie; Larsen, Torkel; Skiftesvik, Anne Berit; Browman, Howard (Peer reviewed; Journal article, 2022)
      In the North Sea, the number and size of offshore wind (OW) turbines, together with the associated network of High Voltage Direct Current (HVDC) subsea cables, will increase rapidly over the coming years. HVDC cables produce ...

    • Measurements of underwater noise radiated by commercial ships at a cabled ocean observatory 

      Zhang, Guosong; Forland, Tonje Nesse; Johnsen, Espen; Pedersen, Geir; Dong, Hefeng (Journal article; Peer reviewed, 2020)
      Measurements of underwater noise radiated under ship normal operations are presented. The acoustic data, from the cabled ocean observatory, are analyzed under each identified ship passage, which was obtained by the Automatic ...

    • Measuring distribution and density of sprat in Årdalsfjorden with a kayak drone - 15-16 August 2020 

      Johnsen, Espen; Totland, Atle; Kvamme, Cecilie (Rapport fra havforskningen;2020 - 28, Research report, 2020)
      Sprat is a key species in several Norwegian fjords, as an important prey for fish, sea mammals and sea birds. The sprat populations are monitored with routine acoustic-trawl surveys using a large research vessel, which ...

    • Panel-based Assessment of Ecosystem Condition of the North Sea Shelf Ecosystem 

      Arneberg, Per; Husson, Berengere; Siwertsson, Anna; Albretsen, Jon; Børsheim, Knut Yngve; Denechaud, Côme; Durant, Joël; Falkenhaug, Tone; Fauchald, Per; Opdal, Anders Martin Frugård; Jentoft, Sissel; Johannessen, Tore; Johnsen, Espen; Jones, Elizabeth Marie; Kvamme, Cecilie; Ljungström, Anna Jeja Gabriella; Buhl-Mortensen, Pål; Reecht, Yves; Solvang, Hiroko Kato; Skogen, Morten D.; Slotte, Aril; Strand, Espen; Søvik, Guldborg; van der Meeren, Gro Ingleid (Rapport fra havforskningen;2023 - 17, Research report, 2023)
      The System for Assessment of Ecological Condition, coordinated by the Norwegian Environment Agency, is intended to form the foundation for evidence-based assessments of the ecological condition of Norwegian terrestrial and ...

    • Panel-based Assessment of Ecosystem Condition of the North Sea Shelf Ecosystem - Appendices 

      Arneberg, Per; Husson, Berengere; Siwertsson, Anna; Albretsen, Jon; Børsheim, Knut Yngve; Denechaud, Côme; Durant, Joël; Falkenhaug, Tone; Fauchald, Per; Opdal, Anders Martin Frugård; Jentoft, Sissel; Johannessen, Tore; Johnsen, Espen; Jones, Elizabeth Marie; Kvamme, Cecilie; Ljungström, Anna Jeja Gabriella; Buhl-Mortensen, Pål; Reecht, Yves; Solvang, Hiroko Kato; Skogen, Morten D.; Slotte, Aril; Strand, Espen; Søvik, Guldborg; van der Meeren, Gro Ingleid (Rapport fra havforskningen;2023 - 18, Research report, 2023)

    • Råd for tobisfiskeriet i norsk sone for 2022 - Tobistokt i Nordsjøen 27. april-12. mai 2022 

      Johnsen, Espen (Toktrapport;2022 - 6, Research report, 2022)
      Tobistoktet i 2022 viser at rekrutteringen (ettåringer) av havsil (tobis) i sørlige del av norsk sone av Nordsjøen er lavere enn middels, men individvekten for disse ettåringene er høyere enn gjennomsnittet i tidsserien ...

    • StoX applied to cod and haddock data from the Barents Sea NOR-RUS ecosystem cruise in autumn - Swept area abundance, length and weight at age 2004-2017 

      Johannesen, Edda; Johnsen, Espen; Johansen, Geir Odd; Korsbrekke, Knut (Fisken og Havete;2019 - 6, Research report, 2019)
      North East Arctic cod and haddock are the largest stocks of these species in the world. Data from the Barents Sea NOR-RUS ecosystem cruise (BESS) in autumn is used as input to the assessment of these species. Here, we used ...

    • StoX: An open source software for marine survey analyses 

      Johnsen, Espen; Totland, Atle; Skålevik, Åsmund; Holmin, Arne Johannes; Dingsør, Gjert Endre; Fuglebakk, Edvin; Handegard, Nils Olav (Journal article; Peer reviewed, 2019)
      Scientists across the globe conduct survey programs to monitor and characterize abundance, population structure, biodiversity and geographical distributions. To assess the state of marine fish and zooplankton, population ...

    • Survey report for CRIMAC SFI 2023 

      Handegard, Nils Olav; Allken, Vaneeda; Holmin, Arne Johannes; Johnsen, Espen; Korneliussen, Rolf; Pedersen, Geir; Skjefstad, Joakim; Rogge, Rabea Patricia; Samuelsen, Mikal Arntzen; Tenningen, Maria; Sivle, Lise Doksæter (Toktrapport;2024 - 7, Research report, 2024)
      This cruise report describes the objectives, methods, and preliminary results from the tasks carried out at the CRIMAC SFI survey. The survey was conducted on board RV G.O. Sars between November 15th (Tromsø) and November ...

    • Tobis ved Vestlandet og i Nordsjøen 1950 - 1990 

      Tangen, Magnus; Hamre, Johannes; Johnsen, Espen; Nakken, Odd; Nedreaas, Kjell; Tangen, Øyvind; Ågotnes, Per (Fisken og havet;5-2016, Research report, 2016-10-25)
      The report is based on interviews with fishermen and written sources that deal with sandeels and sandeel fishing periods along the coast of estern Norway. Observations, stories and figures are put together in an attempt ...

    • Tobistokt i Nordsjøen [18/4 - 10/5, 2010] 

      Johannessen, Tore; Johnsen, Espen ([Toktrapport/Havforskningsinstituttet];Nr. 10 - 2010, Working paper, 2010)

    • Tobistokt i Nordsjøen [22/4 - 9/5, 2011] 

      Johnsen, Espen; Ona, Egil; Pedersen, Ronald (Toktrapport/Havforskningsinstituttet;Nr. 3 - 2011, Working paper, 2011)

    • Tobistokt i Nordsjøen [3/5 - 24/5, 2009] 

      Johannessen, Tore; Johnsen, Espen ([Toktrapport/Havforskningsinstituttet];Nr. 9 - 2009, Working paper, 2009-11-25)

    • Toktrapport fra økosystemtokt i Vestlandsfjordene — Hydrografi, vannkjemi, reker, krill, bunnfisk, tobis og perifylla 

      Søvik, Guldborg; Falkenhaug, Tone; Zimmermann, Fabian; Gallo, Natalya; Nedreaas, Kjell Harald; Danre, Jean-Baptiste; Hovland, Terje; Thangstad, Trude Hauge; Olsen, Siri Aaserud; Johnsen, Espen; Asplin, Lars (Toktrapport;2023 - 11, Research report, 2023)
      Den Strategiske instituttsatsingen CoastRisk (2019–2023) har hatt som mål å styrke kunnskapsgrunnlaget om ulike påvirkningsfaktorers betydning for kystøkosystemenes tilstand, funksjon og utvikling. Vestland fylke er ett ...

    • Underwater noise from wind at the high north LoVe ocean observatory 

      Ødegaard, Lars Alf; Pedersen, Geir; Johnsen, Espen (Peer reviewed; Journal article, 2019)

    • Video Image Enhancement and Machine Learning Pipeline for Underwater Animal Detection and Classification at Cabled Observatories 

      Lopez-vazquez, Vanesa; Lopez-guede, Jose Manuel; Marini, Simone; Fanelli, Emanuela; Johnsen, Espen; Aguzzi, J. (Peer reviewed; Journal article, 2020)
      An understanding of marine ecosystems and their biodiversity is relevant to sustainable use of the goods and services they offer. Since marine areas host complex ecosystems, it is important to develop spatially widespread ...