The probability of cod (Gadus morhua) and ling (Molva molva) to encounter gillnets based on in situ fish movements

• Main Authors: Engås, Arill, Jørgensen, Terje
• Format: Report
• Language: English
• Published: ICES 1997
• Subjects: cod; torsk; ling; lange; gill net; garn; fish behaviour; fiskeatferd; VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485; VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452; VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925; Garn; Gadus morhua
• Online Access: http://hdl.handle.net/11250/105773

The probability of cod (Gadus morhua) and ling (Molva molva) to encounter a fleet of four gillnets (110m) set within a fixed survey area of 600x600 m2 and soaked for a period of 12 h (1800-0600 hrs) is calculated on the basis of in situ observations of fish movement and random simulated start positions and setting directions of a fleet of gillnets. The movements of cod and ling, which were tagged by allowing them to voluntarily swallow bait-wrapped transmitters close to the sea bed, were studied by means of a stationary positioning system. The expected number of encounters per fish for the fleet of gillnets varied between 0.127 and 0.626 for cod and 0.077 and 0.614 for ling with a fish density of three fish per 0,1 (n.mile)^2 .