CEFAS1171372a-92df-4122-8c75-a9b744d2cd47 English CEFAS7c66106f-2073-437a-8470-0fc8e59fb91a 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 2023-01-31T02:06:33 EPSG Geodetic Parameter Registry 2022-01-07 revision WGS 84 Nephrops underwater TV Surveys in the North Sea (video data and database) Nephrops burrow counts 2014-06-13 publication 2023-01-31 revision 2011-10-07 creation CEFAS266 https://data.cefas.co.uk Underwater TV (UWTV) surveys dataset, used as basis of the Nephrops ( *Nephrops**norvegicus*) assessment to develop fishery independent indicators of stock size, exploitation status and catch advice. The standard methodology involves the use of a sledge mounted camera to film the seabed at a fix grid of stations conducting TV tows for 10 minutes. Data has been collected twice a year between 1997 to 2002 (Spring and Autumn) and once a year since 2003 (autumn). Dataset holds data from two areas of the North Sea (Farn Deeps-FU6 (1996 to 2012) and Botney Gut/Silver Pit-FU5 (2010 to 2012)). 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 Department for Environment, Food and Rural Affairs (DEFRA) defra.helpline@defra.gov.uk owner European Commission info@publications.europa.eu owner annually Biota abundance, biomass and diversity Fisheries SeaDataNet P03 parameter discovery vocabulary 2011-03-25 revision Crustacean Shellfish Stock (biological) GEMET, version 1.0 2008-06-01 publication Species distribution GEMET - INSPIRE themes, version 1.0 2008-06-01 publication Benthic boundary Sediment 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 Public data - no limitations to reuse English biota -1.50 4.00 53.50 55.75 1996 2012-09-18 Unknown https://data.cefas.co.uk/view/266 Cefas Data Portal information The Cefas Data Portal contains metadata records and data sets available to download and connect to in support of our commitment to open science. 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 The full dataset consists of approximately 160+ VHS tapes (1996 to 2002) and 260+ DVD discs (2003 to present) plus additional back-up tapes. The DVD discs are kept for reference and quality-control purposes at Cefas, Lowestoft, for a period of 5 years, after which they are disposed of. The VHS tapes are now obsolete but will be retained until January 2017 at which time they will be disposed of. Material can be made available upon request (please contact data steward for more information). Positional data and Nephrops burrow counts have been stored in a shellfish access database since 1996. In line with SGNEPS (Study Group Nephrops) recommendations all scientists are trained/re-familiarised using training material and validated using reference footage (measured by Linn’s concordance correlation coefficient (CCC)) prior to recounting each survey footage. A limit of 0.5 is used to identify counters who need further training. On completion of this process, all survey recounts are conducted, as blind counts, by two persons during the survey. Here, the number of Nephrops burrow systems and the activity in and out of the burrows are counted by each minute block (for 7 clear minutes). In cases where the field of view became obscured by cloud, the number of seconds obscured are recorded and all minute blocks with more than 20 seconds obscured are rejected for analysis. After all counts completed again the Linn’s CCC is again applied to check which stations needed to be revisited and were a 3rd or 4th counter needed to be added. Whilst reviewing the videos, the visibility, ground type, trawl marks, occurrence of bio-fauna, ground contact of the sledge, cloud and any other interference is recorded during each one-minute intervals, using a classification key. Example footage and a training presentation are available via the metadata record entitled 'Nephrops underwater TV Surveys - VHS and DVD footage'. For sediment analysis data of these grounds please contact the Cefas sedimentology team. For acoustic data recorded in these grounds (multibeam and backscattered data) please contact Cefas MIST team. MEDIN 3.1.1