How to avoid fish bycatch in shrimp trawls using behaviour differences

Present sorting device used in shrimp trawling, the Nordmøre grid, is not efficent to release fish smaller than 18 cm. Shrimp fishing grunds therefore have to be closed for fishing during the months Nobember-June when juvenile cod and haddock have settled to the bottom. Recent studies have demontrated clear differences in behavior of shrimp and fish inside the trawl. Whereas fish react by swimming away from the netting, shrimp show no reaction such as they follows the netting backwards to the codend. This behaviour behaviour difference will be further investigated in the project as basis for development of technical solutions that can be implemented in commercial shrimp trawls. The project will thus include behaviour studies in field situations, technica l development using flume tank and smaller fishing vessels prior to fullscale testing of promising devices. The project activity is part of a larger program for developmet of future trawling technology for shrimp, where size selection of shrimp and a mor e energy efficient trawl are two other important components.