CEFAS5efa0e00-6a3e-4e8f-b75d-49d7bbacbc2e English dataset Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk pointOfContact 2025-11-06T01:11:10 EPSG Geodetic Parameter Registry 2022-01-07 revision WGS 84 Testing cod end and square mesh panel configurations in the English SW otter trawl fishery 2020/21 - Fisheries Science Partnership Report_67_ SW_demersal_trawl_selectivity _2020_21 2022-01-19 publication 2025-11-06 revision 2021-11-30 creation CEFAS21389 https://data.cefas.co.uk 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. Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk originator Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk custodian Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk distributor Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) data.manager@cefas.co.uk owner Department for Environment, Food and Rural Affairs (DEFRA) defra.helpline@defra.gov.uk owner notPlanned Fish Biota abundance, biomass and diversity Fisheries SeaDataNet P03 parameter discovery vocabulary 2011-03-25 revision Fish abundance in water bodies SeaDataNet P02 parameter discovery vocabulary 2011-03-25 revision Benthos GEMET, version 1.0 2008-06-01 publication Species distribution GEMET - INSPIRE themes, version 1.0 2008-06-01 publication Water column SeaVoX Vertical Co-ordinate Coverages 2010-05-18 revision Marine Environmental Data and Information Network MEDIN metadata record availability 2012-01-11 publication data.gov.uk MEDIN metadata record availability 2012-01-11 publication otherRestrictions noLimitations otherRestrictions **Publicly available data licensed under the Open Government Licence v3.0 (`https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/)`_ – Please note the applicable attribution statement is as follows: ‘includes Crown copyright, Cefas 2021'** .. _`https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/)`: https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ English biota -4.00 -0.50 50.00 51.00 2020-10 2020-12 Binary Unknown https://data.cefas.co.uk/view/21389 Cefas Data Portal download The Cefas Data Portal contains metadata records and data sets available to download and connect to in support of our commitment to open science. Data is available in the following formats: Binary download. dataset INSPIRE Data Specification on Species Distribution – Technical Guidelines 2013-12-10 publication false See the referenced specification Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 publication true See the referenced specification A fixed routine for handling and sorting the catch was maintained throughout the trials. Catches from the two cod ends were always kept separate and were processed as either the retained or discarded fraction. Cefas observers sampled using standard techniques. For each haul, all fish species caught were measured to the nearest cm below. Sub sampling was necessary on occasions when the fish catch was large, and raising factors were calculated accordingly. Additionally, benthos was separated from the discarded fish, identified down to group level, and counted. The results were compiled in Excel and plotted graphically in R. MEDIN 3.1.1