Objetivo The aim of the research is the development of a species selective beam trawl with special emphasis on a substantial decrease of the discards of young roundfish while maintaining the level of flatfish catches. The beam trawls of the participating Countries are aimed at flatfish but also catch quite large quantities of roundfish, which are often immature and not saleable. Even if this bycatch fish is of marketable size, it must often be rejected at sea due to the quota systems in operation. It is therefore desirable to develop gear which will reduce the roundfish bycatch of beam trawls without affecting catches of the desired flatfish species. Models of the representative gears were built and tested. Numerous ideas for selectivity devices were worked on at model scale. The most promising were selected for further testing at full scale. The criteria for selection included likely effectiveness for selectivity, practicality and costs for commercial production, and likely problems in handling at sea. Large diamond mesh and large hexagonal mesh top panels were chosen for the V Net and a square mesh top panel, a cut away top panel, and a combination of this with different sizes of square mesh windows were chosen for the R Net. Full scale versions of these options were observed in action at sea. The results indicate a good potential for improving the species selectivity of beam trawls especially for rejecting whiting and haddock without effecting flatfish catches. The results for cod are inconsistent in different seasons and times of the day. The devices which seem most effective are the large diamond mesh top panel for the V Nets and a cutaway top panel allied with square mesh window for R Nets.The research work comprises the following main phases. A short inventory will be made of the vessels involved in the different countries and of the dimensions of their fishing gears as well as the various legislation and technical measures in the beam trawl fishery among the EC states participating in this project. At the end of this phase the state of the art will be summarised and the net designs and alternative riggings to be tested at model scale identified. Net and codend models of the proposed configurations will be designed and built. The models will be tested in a flume tank. From the results of these experiments the most promising configurations will be selected for the trials at full scale at sea. After design and construction of the most promising beamtrawl configurations, initial trials will be conducted on a chartered commercial fishing vessel to appraise the engineering aspects and fish behaviour by direct observation techniques. For the sake of comparison the escape from traditional gears will be studied as well. Selectivity experiments will be carried out onboard chartered commercial vessels. The experiments will involve both tickler chain and chainmat beamtrawls. Representative engine powers will be chosen. The selectivity of the experimental nets and of a standard control gear will be determined simultaneously for both the target flatfish species (sole, plaice) and for the prevailing roundfish species. The data will be analysed using computer facilities. Ámbito científico agricultural sciencesagriculture, forestry, and fisheriesfisheries Programa(s) FP2-FAR - Community research and coordination programmes (EEC) in the fisheries sector, 1988-1992 Tema(s) Data not available Convocatoria de propuestas Data not available Régimen de financiación Data not available Coordinador Rijksinstituut voor Visserijonderzoek (RIVO) Aportación de la UE Sin datos Dirección Postbus 68, Haringkade 1 1970 AB Ijmuiden Países Bajos Ver en el mapa Coste total Sin datos Participantes (2) Ordenar alfabéticamente Ordenar por aportación de la UE Ampliar todo Contraer todo RIJKSSTATION VOOR ZEEVISSERIJ Bélgica Aportación de la UE Sin datos Dirección Oostende Ver en el mapa Coste total Sin datos Sea Fish Industry Authority Reino Unido Aportación de la UE Sin datos Dirección St Andrew's Dock HU3 4QE Hull Ver en el mapa Coste total Sin datos
