Testing cod end and square mesh panel configurations in the English SW otter trawl fishery 2020/21 - Fisheries Science Partnership dataset https://portal.medin.org.uk/portal/start.php?tpc=009_CEFAS5efa0e00-6a3e-4e8f-b75d-49d7bbacbc2e This work was carried out as part of the Fisheries Science Partnership (FSP) programme. The primary objective of the project was to obtain data on the differences between the currently permitted and proposed new trawl configurations, principally to move from the widespread use of 80mm mesh cod end to a default of 100mm. This information will help to provide evidence on the performance of more selective trawl configurations to inform on proposed changes to technical measures regulations in the southwest otter trawl mixed fishery. For this purpose, two trials lasting 6 days each took place in ICES Division 7e on the twin-rig otter trawler Rockfisher (SU6) in the months of October to December 2020. The vessel conducted simultaneous comparative tows of the control gear and two experimental gears. The first trial compared two trawls, both with 100mm cod ends, and one with an 80mm square mesh panel (SMP) and the other with 100mm SMP. A total of 19 paired hauls were collected for this trial. The second trial compared 100mm cod end with an 80mm SMP to an 80mm cod end with an 80mm SMP (as normally used by the vessel). A total of 14 paired hauls were completed for the second trial. At each station sampled, shot and haul, positional, times, depths and towing speed information were recorded, and for all species of fish length distribution data were taken, including collecting data on the benthic component of the catch. 20220119 20211130