In 2004, comparative selectivity investigations were made with the now legal BACOMA codend of 110 mm mesh opening and alternative codends made of netting turned 90° of similar mesh openings on both commercial boats and on research vessels. The results show a certain variability of the BACOMA results – depending on ship type and season (L50 varying between 36,8 and 40,6) – and a general equal efficiency of codends made of netting turned 90° of the same mesh opening. Underwater observations and reduced performance of codends of equal circumference in meshes as the joining round at the end of the tapered part of the trawl indicate the need to reduce the relation of the cir-cumferences of codend and extension to 1 to 0.7 to achieve optimum fit and selectivity.
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