Assessment of Innovative Selective Codends in Baltic Cod Fishing

The objective of the presented study was assessment of the selectivity properties of three codends designed in Maritime University of Szczecin, Poland for Baltic cod fishing: 1) an ultracross codend of 120 mm square mesh, 2) ultracross codend with additional devices reducing the speed of water flow - one tarpaulin diffuser and one net confusor of 120 mm mesh, 3) ultracross codend with two tarpaulin diffusers and two net confusors of 120 mm mesh. Validation of these codends selectivity was done by comparison of single trawls using each tested codend results with results of trawls using T90 codend and of trawls using a double (twin) bottom trawl set deployed in various variants of innovative, T90 and herring codends. The results of the study indicate that the use of an ultracross codend with innovative devices reducing the water flow speed (with two tarpaulin diffusers and two 120 mm net confusors) significantly reduces the number of undersized cod (<35 cm) even down to 1.2% in the haul.