Antarctic krill; assessment of mesh size selectivity and escape mortality from trawls

This working paper presents the aims and methodology for a three-year-project (commenced in 2015) assessing size selectivity and escape mortality of Antarctic krill from trawl nets. The project is widely based on acquired experiences from a completed study Net Escapement of Antarctic krill in Trawls (NEAT), presented in WG-EMM 2012/24, WG-EMM 2013/34, WG-EMM 2014/14 and WG-EMM 2014/16. Funding is provided by the Norwegian Research Council and ship-time for executing the field-experiments is offered free-of-charge by two Norwegian commercial fishing companies; Olympic Seafood AS and Aker BioMarine AS. The project will examine krill escape mortality from the codend during a full scale field experiment, model size selectivity and escape mortality in codends including different designs and assess the size selectivity in the trawl body forward of the codend. Based on end results from the preceding examinations we will be able to predict size selectivity and escape mortality from the entire trawl body with the appurtenant mortality for different trawl designs.