Blar i Brage IMR på forfatter "Somerton, David"
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Fish behaviour during sampling as observed from free floating buoys - application for bottom trawl survey assessment
Godø, Olav Rune; Somerton, David; Totland, Atle (ICES CM documents, Working paper, 1999)Varying fish distribution and behaviour during bottom trawl surveys has long been considered important for the reliability of survey abundance estimates. Size and species dependent behaviour may bias the estimates and ... -
Incorporating experimentally derived estimates of survey trawl catchability into the stock assessment process
Somerton, David; Ianelli, Jim; Walsh, Stephen J.; Smith, Stephen; Godø, Olav Rune; Ramm, David (ICES CM Documents;1997/W:5, Working paper, 1997)During the course of the April, 1996, meeting of the Fishing Technology and Fish Behavior Working Group it became clear to many that the methodology for experimentally estimating the catchability of survey trawls might ... -
Quantifying the amount of fish unavailable to a bottom trawl by use of an upward looking transducer
Michalsen, Kathrine; Aglen, Asgeir; Somerton, David; Svellingen, Ingvald; Øvredal, Jan Tore (ICES CM documents, Working paper, 1999)When surveying demersal fish with a wide and variable vertical distribution, it is desirable to combine information from a bottom trawl survey with the information from a hydroacoustic survey into an absolute abundance ...