Blar i Brage IMR på forfatter "Beare, Douglas"

Viser treff 1-3 av 3

    • Can subjective evaluation of echograms improve correlation between bottom trawl and acoustic densities? 

      Godø, Olav Rune; Hjellvik, Vidar; Greig, Tony; Beare, Douglas (ICES CM documents, Working paper, 2004)
      Direct comparison of acoustic densities and trawl catches involves fundamental difficulties related to species and size selectivity of the trawl and efficiency of the acoustic instrumentation. In some surveys, therefore, ...

    • Differences between near bottom biomass spatial structure observed in the Irish Sea, the North Sea and the Barents Sea in recent years 

      Mireille, Bouleau; Nicolas, Bez; Hjellvik, Vidar; Godø, Olav Rune; Reid, David; Beare, Douglas; Greig, Tony; Armstrong, Mike; Gerritsen, Hans D.; Mackinson, Steven; Neville, Suzanna; Kooij, Jeroen van der; Vérin, Yves; Massé, Jacques (ICES CM documents, Working paper, 2003)
      Based on acoustic data and trawl catches collected during bottom trawl surveys, we compare the spatial structure of the biomass available in the first meters above the bottom in three different regions, the Barents Sea ...

    • Positive relationships between bottom trawl and acoustic data 

      Beare, Douglas; Reid, David; Greig, Tony; Bez, Nicholas; Hjellvik, Vidar; Godø, Olav Rune; Bouleau, Mireille; Kooij, Jeroen van der; Neville, Suzanna; Mackinson, Steven (ICES CM documents, Working paper, 2004)
      Demersal fish stock biomass is usually estimated using commercial landings data, ‘tuned’ by various types of survey data, usually trawl. When collecting fish data by trawl it is only possible to take relatively small numbers ...