Browsing Øvrige samlinger by Author "Røstad, Anders"

Now showing items 1-11 of 11

  • Diel vertical migration and individual behavior of nekton beyond the ocean's twilight zone 
    Kaartvedt, Stein; Røstad, Anders; Christiansen, Svenja; Klevjer, Thor Aleksander (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 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 ...
  • Ecology of overwintering sprat (Sprattus sprattus) 
    Solberg, Ingrid; Røstad, Anders; Kaartvedt, Stein (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We used moored upward-facing echosounders in combination with field campaigns to address the overwintering ecology of the clupeid sprat (Sprattus sprattus) throughout four separate winters in a Norwegian fjord. The stationary ...
  • Flexible behaviour in a mesopelagic fish (Maurolicus muelleri) 
    Christiansen, Svenja; Klevjer, Thor Aleksander; Røstad, Anders; Aksnes, Dag Lorents; Kaartvedt, Stein (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 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 ...
  • Herding mesopelagic fish by light 
    Kaartvedt, Stein; Røstad, Anders; Opdal, Anders Frugård; Aksnes, Dag Lorents (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    To assess organisms forming mesopelagic scattering layers in the Red Sea, we took advantage of their reactions to light. We used a remotely operated vehicle (ROV) equipped with LED lamps for herding the acoustic targets ...
  • Individual daytime swimming of mesopelagic fishes in the world’s warmest twilight zone 
    Sobradillo, Beatriz; Christiansen, Svenja; Røstad, Anders; Kaartvedt, Stein (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    We assessed the activity and swimming patterns of mesopelagic fishes in the Red Sea using bottom-moored, upward-facing echosounders deployed at 555 and 700 m depth. The vertically migrating mesopelagic scattering layer ...
  • 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 / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    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 ...
  • Light comfort zones of mesopelagic acoustic scattering layers in two contrasting optical environments 
    Røstad, Anders; Kaartvedt, Stein; Aksnes, Dag Lorents (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    We make a comparison of the mesopelagic sound scattering layers (SLs) in two contrasting optical environments; the clear Red Sea and in murkier coastal waters of Norway (Masfjorden). The depth distributions of the SL in ...
  • Light penetration structures the deep acoustic scattering layers in the global ocean 
    Aksnes, Dag Lorents; Røstad, Anders; Kaartvedt, Stein; Martinez, Udane; Duarte, Carlos M.; Irigoien, Xabier (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    The deep scattering layer (DSL) is a ubiquitous acoustic signature found across all oceans and arguably the dominant feature structuring the pelagic open ocean ecosystem. It is formed by mesopelagic fishes and pelagic ...
  • The mesopelagic scattering layer: A hotspot for heterotrophic prokaryotes in the Red Sea twilight zone 
    Calleja, Maria Ll; Ansari, Mohd I; Røstad, Anders; Silva, Luis; Kaartvedt, Stein; Irigoien, Xabier; Moran, Xose Anxelu G (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The vast majority of marine dissolved organic carbon (DOC), the largest reservoir of reduced carbon on Earth, is believed to accumulate in the abyssal layers of the ocean over timescales of decades to millennia. However, ...
  • Sleep walking copepods? Calanus diapausing in hypoxic waters adjust their vertical position during winter 
    Kaartvedt, Stein; Røstad, Anders; Titelman, Josefin (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Abstract While hypoxia is generally associated with negative connotations, some animals may also take advantage of reduced oxygen concentrations. However, the dynamics of such processes for zooplankton are poorly ...
  • Social behaviour in mesopelagic jellyfish 
    Kaartvedt, Stein; Ugland, Karl Inne; Klevjer, Thor A.; Røstad, Anders; Titelman, Josefin; Solberg, Ingrid (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Gelatinous organisms apparently play a central role in deep pelagic ecosystems, but lack of observational methodologies has restricted information on their behaviour. We made acoustic records of diel migrating jellyfish ...