The reduction of cod discards by inserting 300 mm diamond mesh netting in the forward sections of a trawl gear

摘要

The results of catch comparison trials of a trawl gear, where the 160 mm mesh size netting in the forward sections of the gear is replaced with 300 mm mesh size netting, are presented. This gear, which has become known as the 'Orkney gear', was designed to reduce, but not eliminate, catches of Atlantic cod in the North Sea mixed whitefish fishery. The results show that the modified gear retains significantly fewer cod smaller than 78 cm while, above 78 cm, there is no significant difference in the amount of cod caught. Catches of monkfish were 16% less, however, there was no significant difference in the numbers of monkfish caught above 55 cm. There was about a 43% loss of megrim across all length classes and there were no losses of haddock and whiting. Crown Copyright