• Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic 

      Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert; Mogstad, Aksel Alstad; Zolich, Artur Piotr; Last, Kim (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-25)
      The jellyfish <i>Periphylla periphylla</i>, which can have strong ecological impacts on its environment, is ubiquitous in the Norwegian Sea and its range was predicted to extend northwards. The occurrence of <i>P. periphylla</i> in the northern Barents Sea increased since 2014 and, for the first time, several individuals were collected within a high Arctic fjord (> 78°N) in western Spitsbergen in ...
    • Model-informed classification of broadband acoustic backscatter from zooplankton in an in situ mesocosm 

      Dunn, Muriel Barbara; McGowan-Yallop, Chelsey; Pedersen, Geir; Falk-Petersen, Stig; Daase, Malin Hildegard Elisabeth; Last, Kim; Langbehn, Tom; Fielding, Sophie; Brierley, Andrew S.; Cottier, Finlo Robert; Basedow, Sünnje Linnéa; Camus, Lionel; Geoffroy, Maxime (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-07)
      Classification of zooplankton to species with broadband echosounder data could increase the taxonomic resolution of acoustic surveys and reduce the dependence on net and trawl samples for ‘ground truthing’. Supervised classification with broadband echosounder data is limited by the acquisition of validated data required to train machine learning algorithms (‘classifiers’). We tested the hypothesis ...
    • Pelagic organisms avoid white, blue, and red artificial light from scientific instruments 

      Geoffroy, Maxime; Langbehn, Tom; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault; Fisher, Jonathan A. D.; Daase, Malin; Mckee, David; Cohen, Jonathan H.; Berge, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-22)
      In situ observations of pelagic fish and zooplankton with optical instruments usually rely on external light sources. However, artificial light may attract or repulse marine organisms, which results in biased measurements. It is often assumed that most pelagic organisms do not perceive the red part of the visible spectrum and that red light can be used for underwater optical measurements of biological ...