ICES WGBEAM REPORT 2013 SCICOM STEERING GROUP ON ECOSYSTEM SURVEYS SCIENCE AND TECHNOLOGY ICES CM 2013/SSGESST:12 REF. SCICOM & ACOM Report of the Working Group on Beam Trawl Surveys (WGBEAM) 23-26 April 2013 Ancona, Italy International Council for the Exploration of the Sea Conseil International pour l’Exploration de la Mer H. C. Andersens Boulevard 44–46 DK-1553 Copenhagen V Denmark Telephone (+45) 33 38 67 00 Telefax (+45) 33 93 42 15 www.ices.dk [email protected] Recommended format for purposes of citation: ICES. 2013. Report of the Working Group on Beam Trawl Surveys (WGBEAM), 23-26 April 2013, Ancona, Italy. ICES CM 2013/SSGESST:12. 260 pp. For permission to reproduce material from this publication, please apply to the Gen- eral Secretary. The document is a report of an Expert Group under the auspices of the International Council for the Exploration of the Sea and does not necessarily represent the views of the Council. © 2013 International Council for the Exploration of the Sea ICES WGBEAM REPORT 2013 | i Contents Executive summary ................................................................................................................ 1 1 Opening of the meeting ................................................................................................ 3 2 Adoption of the agenda ................................................................................................ 3 3 Introduction .................................................................................................................... 3 3.1 Terms of reference ................................................................................................ 3 4 Review of WGBEAM 2012 recommendations and other requests to WGBEAM ........................................................................................................................ 4 4.1 WGBEAM 2012 recommendations ..................................................................... 4 4.2 Actions for WGBEAM during 2012 .................................................................... 5 5 Coordinate offshore and coastal beam trawl surveys in the North Sea and Divisions VIIa, VIId-g and VIIIa-b; (ToR b) .................................................... 8 5.1 Results of 2012 surveys ........................................................................................ 8 5.1.1 Offshore surveys ...................................................................................... 8 5.1.2 Survey summary sheets offshore surveys per country .................... 10 5.2 Inshore surveys ................................................................................................... 30 5.2.1 Participation and coverage of the area ................................................ 30 5.2.2 Survey results ......................................................................................... 30 5.2.3 Catch results ........................................................................................... 31 5.2.4 Survey summary sheets inshore surveys per country ...................... 32 5.3 Coordination and standardization of beam trawl surveys in 2013 .............. 44 5.3.1 Offshore beam trawl surveys ............................................................... 44 5.3.2 Inshore beam trawl surveys ................................................................. 44 6 Population abundance indices (ToR a) .................................................................... 46 6.1 Abundance indices by age-group for plaice and sole for the offshore surveys .................................................................................................. 46 6.1.1 Sole ........................................................................................................... 46 6.1.2 Plaice ........................................................................................................ 48 6.2 Abundance indices by age-group for plaice and sole for the inshore surveys ................................................................................................... 65 6.2.1 Population abundance indices ............................................................. 65 6.2.2 Revision of the inshore indices ............................................................ 67 6.2.3 Evaluation of the (combined) inshore indices.................................... 69 6.3 Investigations on the Bay of Biscay sole abundance index ........................... 69 6.3.1 Creation of time-series for the ORHAGO survey in the Bay of Biscay sole........................................................................................... 69 6.3.2 Patterns in day vs. night hauls ............................................................. 70 6.3.3 Variance ................................................................................................... 71 6.3.4 Behaviour in XSA ................................................................................... 71 ii | ICES WGBEAM REPORT 2013 7 DATRAS related topics .............................................................................................. 76 7.1 Index calculation for plaice and sole based on DATRAS data ..................... 76 7.1.1 Methodology .......................................................................................... 76 7.1.2 Next steps ................................................................................................ 76 7.2 Checks on offshore beam trawl survey data in DATRAS ............................. 77 7.2.1 Checking distance against duration, speed and calculated distance .................................................................................................... 77 7.2.2 Checking combination of datatype and subfactor ............................ 79 7.2.3 Species inconsistencies .......................................................................... 81 7.2.4 Reporting on benthos species ............................................................... 84 7.2.5 Submitting species of higher taxonomic groups than species level ............................................................................................ 86 7.3 New DATRAS products .................................................................................... 87 7.3.1 Calculation of cpue per haul for BTS data in DATRAS .................... 87 7.3.2 Calculation of ALK, SMALK and indices for BTS data in DATRAS .................................................................................................. 89 8 Sole trends (ToR d) ...................................................................................................... 90 8.1 Sole ........................................................................................................................ 90 8.1.1 Methods ................................................................................................... 90 8.1.2 Results ..................................................................................................... 90 9 Continue work on standardizing the offshore and inshore surveys such as, the reviewing the manuals, updating database and staff exchanges (ToR c and g) ............................................................................................. 94 9.1 Offshore beam trawl survey manual ............................................................... 94 9.2 Inshore beam trawl survey manual ................................................................. 94 9.3 SISP progress ....................................................................................................... 94 9.4 Offshore staff exchange ...................................................................................... 94 9.5 Inshore staff exchange ........................................................................................ 94 9.6 Submission status of BTS offshore data ........................................................... 95 9.6.1 Belgium ................................................................................................... 95 9.6.2 France ...................................................................................................... 95 9.6.3 Italy/Croatia ............................................................................................ 95 9.7 Submission status of BTS inshore data ............................................................ 95 10 Other subjects ............................................................................................................... 96 10.1 Coordination of the Q1SWBeam (UK) survey: ............................................... 96 10.1.1 Timing and area coverage .................................................................... 96 10.1.2 Stratification design ............................................................................... 96 10.1.3 Survey design ......................................................................................... 97 10.1.4 Dataseries and results ........................................................................... 98 10.2 OSPAR Request (ToR f) ................................................................................... 100 11 References ................................................................................................................... 109 ICES WGBEAM REPORT 2013 | iii Annex 1: List of WGBEAM participants ........................................................................ 110 Annex 2: Agenda ................................................................................................................