• Acoustic properties of Salpa thompsoni. 

      Wiebe, Peter H.; Chu, Dezhang; Kaartvedt, Stein; Hundt, Anna (Hölter); Melle, Webjørn; Ona, Egil; Batta-Lona, Paola (ICES CM documents;2009 / I:01, Working paper, 2009)
      Salps are common members of the world oceans planktonic community (Madin, et.al., 2006). In the southern ocean, both krill (Euphausia superba) and salps (Salpa thompsoni) can occur in dense aggregations (Loeb et al, 2009, ...
    • Acoustic visualization of large scale macroplankton and micronekton distributions across the Norwegian shelf and slope of the Norwegian Sea. 

      Melle, Webjørn; Kaartvedt, Stein; Knutsen, Tor; Dalpadado, Padmini; Skjoldal, Hein Rune (ICES CM Documents;1993/L:44, Working paper, 1993)
      We present results from acoustical (38 kHz split beam) surveys, biological sampling (trawling, zooplankton nets), and measurements of physical parameters (salinity, temperature, currents) across and along the shelf ...
    • Behavior of individual mesopelagic fish in acoustic scattering layers of Norwegian fjords 

      Kaartvedt, Stein; Torgersen, Thomas; Klevjer, Thor A.; Røstad, Anders; Devine, Jennifer A. (Journal article; Peer reviewed, 2008-05-22)
      Mesopelagic acoustic scattering layers (SLs) in 2 fjords were studied from a stationary research vessel. Diel vertical movements of SLs were assessed by hull-mounted transducers, while in situ behavior of individuals ...
    • Can predator avoidance explain varying overwintering depth of Calanus in different oceanic water masses? 

      Dale, Trine; Bagøien, Espen; Melle, Webjørn; Kaartvedt, Stein (Journal article; Peer reviewed, 1999-04-15)
      Distributions of overwintering Calanus spp. in the upper 1000 m in the Norwegian and Greenland Seas were studied in relation to hydrography, invertebrate predators and acoustic scattering layers (38 kHz). C, finmarchicus ...
    • Coastal water darkening and implications for mesopelagic regime shifts in Norwegian fjords 

      Aksnes, Dag Lorents; Dupont, Nicolas; Staby, Arved; Fiksen, Øyvind; Kaartvedt, Stein; Aure, Jan (Journal article; Peer reviewed, 2009-07-28)
      The light regime of the water column has a strong structuring effect on aquatic food webs and it has been previously hypothesized that coastal water darkening has increased the success of tactile predators relative to ...
    • Diel vertical migration and individual behavior of nekton beyond the ocean's twilight zone 

      Kaartvedt, Stein; Røstad, Anders; Christiansen, Svenja; Klevjer, Thor Aleksander (Peer reviewed; Journal article, 2020)
      Diel vertical migration (DVM) is normally limited to the upper 1000 m. However, the use of ship-borne and stationary submerged echosounders in the Red Sea unveiled consistent formation of daytime patches extending to ...
    • Distribution of herring (Clupea harengus) and zooplankton in the Norwegian Sea, as determined from generalised additive models 

      Olsen, Esben Moland; Melle, Webjørn; Kaartvedt, Stein; Holst, Jens Christian; Mork, Kjell Arne (ICES CM documents, Working paper, 2005)
      We analyse the variability in the distribution and feeding of the Norwegian spring-spawning herring in the period from 1995 to 2004, using survey data collected throughout the Norwegian Sea each year in May - June. The ...
    • Flexible behaviour in a mesopelagic fish (Maurolicus muelleri) 

      Klevjer, Thor Aleksander; Røstad, Anders; Aksnes, Dag Lorents; Kaartvedt, Stein (Peer reviewed; Journal article, 2021)
      Variability of mesopelagic scattering layers is often attributed to environmental conditions or multi-species layer composition. Yet, little is known about variation in behaviour among the individuals forming scattering ...
    • Flexible behaviour in a mesopelagic fish (Maurolicus muelleri) 

      Christiansen, Svenja; Klevjer, Thor Aleksander; Røstad, Anders; Aksnes, Dag Lorents; Kaartvedt, Stein (Peer reviewed; Journal article, 2021)
      Variability of mesopelagic scattering layers is often attributed to environmental conditions or multi-species layer composition. Yet, little is known about variation in behaviour among the individuals forming scattering ...
    • Impact of hatch-date on early life growth and survival of Mueller's pearlside (Maurolicus Muelleri) larvae, and life-history consequences 

      Folkvord, Arild; Gundersen, Geir; Albretsen, Jon; Asplin, Lars; Kaartvedt, Stein; Giske, Jarl (Journal article, 2015)
    • In situ swimming speed and swimming behaviour of fish feeding on the krill Meganyctiphanes norvegica 

      Onsrud, M. S. R.; Kaartvedt, Stein; Breien, M. T. (Journal article; Peer reviewed, 2005)
      In situ swimming speed and swimming behaviour of dielly migrating planktivorous fish were studied at a 120-m-deep location. Acoustic target tracking was performed using a hull-mounted transducer and submersible ...
    • Large scale patterns in vertical distribution and behaviour of mesopelagic scattering layers 

      Klevjer, Thor A.; Irigoien, Xabier; Røstad, Anders; Fraile-Nuez, Eugenio; Benítez-Barrios, Verónica María; Kaartvedt, Stein (Journal article; Peer reviewed, 2016-01-27)
      Recent studies suggest that previous estimates of mesopelagic biomasses are severely biased, with the new, higher estimates underlining the need to unveil behaviourally mediated coupling between shallow and deep ocean ...
    • Mesoscale Eddies Are Oases for Higher Trophic Marine Life 

      Godø, Olav Rune; Samuelsen, Annette; Macaulay, Gavin J.; Patel, Ruben; Hjøllo, Solfrid Sætre; Horne, John K.; Kaartvedt, Stein; Johannessen, Johnny A. (Journal article; Peer reviewed, 2012-01-07)
    • Piscivorous fish patrol krill swarms 

      Kaartvedt, Stein; Røstad, Anders; Fiksen, Øyvind; Melle, Webjørn; Torgersen, Thomas; Breien, M. T.; Klevjer, Thor A. (Journal article; Peer reviewed, 2005-09-01)
      Dense swarms of the krill Meganyctiphanes norvegica in the Norwegian Sea were patrolled by large, piscivorous fish, which apparently use the krill swarms as feeding grounds in their hunt for planktivores. For the krill, ...
    • Schooling of the vertically migrating mesopelagic fish Maurolicus muelleri in light summer nights 

      Kaartvedt, Stein; Knutsen, Tor; Holst, Jens Christian (Journal article; Peer reviewed, 1998-09-03)
      Vertically migrating Maurolicus muelleri arrested their nocturnal ascent below the peak zooplankton concentrations during Light summer nights at 62 degrees N. At 69 degrees N, the behavior was further modified, with M, ...
    • Significance of advection for the carrying capacities of fjord populations 

      Aksnes, Dag Lorents; Aure, Jan; Kaartvedt, Stein; Magnesen, Thorolf; Richard, J. (Journal article; Peer reviewed, 1989-02-02)
      Advective rates of nutrients, phytoplankton and zooplankton were estimated for the Masfjord, western Norway, in June and October 1985. The advective contribution to the phytoplankton biomass formation was dearly less ...
    • Underwater optics and behavioral responses of krill to presence of fish predators affect fish-plankton interactions 

      Kaartvedt, Stein; Skjoldal, Hein Rune; Melle, Webjørn; Knutsen, Tor (ICES CM Documents;1993/L:43, Working paper, 1993)
      In clear oceanic waters off the Norwegian shelf and in outer shelf waters, mesopelagic fish (Maurolicus muelleri) were located at approximately 200 m by day. Across a front into water of lower light penetration, M. ...
    • Vassdragsreguleringers virkning på fjorder 

      Kaartvedt, Stein (Fisken og havet, Research report, 1984)
      Natural freshwater discharge to Norwegian fjords is characterized by low runoff during winter when precipitation is stored as snow and ice, and a marked peak in the discharge due to snow melting in spring. Hydroelectric power ...
    • Vertical distribution of fish and krill beneath water of varying optical properties 

      Kaartvedt, Stein; Melle, Webjørn; Knutsen, Tor; Skjoldal, Hein Rune (Journal article; Peer reviewed, 1996-06-06)
      The distribution of acoustical scattering layers of fish and krill changed markedly in concert with fluctuating fluorescence (chlorophyll a) in upper waters, possibly due to a varying 'shadow effect'. Beneath clear waters ...
    • Økosystemet i østlige Norskehavet; sokkel og dyphav 

      Melle, Webjørn; Knutsen, Tor; Ellertsen, Bjørnar; Kaartvedt, Stein; Noji, Thomas (Rapport fra senter for marint miljø;Nr. 4 - 1993, Working paper, 1993-02-18)
      Biologisk bakgrunnsrapport for konsekvensutredning for området ''Vøringplatået". Oppsummerer hydrografi, strøm, primærproduksjon, benthos, herbivort og karnivort dyreplankton, fiskelarver, fisk og hval. Presenterer nye ...