Total selectivity of a commercial cod trawl with and without a grid mounted: grid and codend selectivity of north-east Artic cod

摘要

The sorting grid was introduced in the Barents Sea gadoid fishery in 1997. During an experiment west of Bear Island in summer 2001, the total selectivity of a commercial cod trawl with a single grid mounted (grid selectivity x codend selectivity) was compared with that of the same trawl without a grid (codend selectivity). This is the first comparison of the selectivity of these gears during a single experiment. The results showed a surprisingly similar selection range for grid and codend selectivity: around 10 cm. With a grid mounted, the 50% retention length of the trawl rose by about 4 cm. The results demonstrate that catch rate or catch size may influence both 50% retention length and selection range.