• Acoustic estimation of size distribution and abundance of zooplankton 

      Kristensen, Åge; Dalen, John (Journal article; Peer reviewed, 1986)
      A series of investigations were undertaken to observe and describe the sound backscattering process from larger zooplankton (euphausiids). The target strength versus frequency, size, and aspect angle of the organism was ...
    • Density in sub-arctic zooplankton 

      Falk-Petersen, Stig; Køgeler, J. W.; Kristensen, Åge; Pettersen, Fritz; Dalen, John (ICES CM documents, Working paper, 1985)
      Seasonal variations in specific density were measured for Thysanoessa inermis, Thysanoessa raschii, Meganyctiphanes norvegica, Calanus finmarchicus and Calanus hyperboreus. The density of a 20 mm T. inermis was lowest in ...
    • Measurements of Target stength and Spatial Orientation of Euphausiids (krill). 

      Dalen, John; Kristensen, Åge (ICES CM Documents;1981/B:l7, Working paper, 1981)