ICES WGCSE REPORT 2017 ICES ADVISORY COMMITTEE ICES CM 2017/ACOM:13 Report of the Working Group on Celtic Seas Ecoregion (WGCSE) 9 18 May 2017 Copenhagen, Denmark
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 info@ices.dk Recommended format for purposes of citation: ICES. 2017. Report of the Working Group on Celtic Seas Ecoregion (WGCSE), 9 18 May 2017, Copenhagen, Denmark. ICES CM 2017/ACOM:13. 1464 pp. For permission to reproduce material from this publication, please apply to the General 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. 2017 International Council for the Exploration of the Sea
ICES WGCSE REPORT 2017 i Contents Executive Summary... 1 1 Introduction... 3 1.1 Terms of reference... 3 1.1.1 Generic ToRs... 3 1.1.2 Specific ToRs... 4 1.1.3 Additional ToR... 5 1.2 Participation... 5 1.3 Methods... 7 1.4 Internal auditing and external reviews... 8 1.5 ToR e WGCSE recommendations for stocks to be benchmarked... 8 1.6 ToR c(ii) Estimation of MSY proxy reference points... 8 1.7 Completion of checklist for upgrading category 3 and 4 stocks... 9 4 Anglerfish (Lophius budegassa and Lophius piscatorius) in subareas 4 and 6, and in Division 3.a (North Sea, Rockall and West of Scotland, Skagerrak and Kattegat)... 10 4.1 General... 10 4.2 Data... 14 4.3 Historical stock development... 17 4.4 Short-term projections... 17 4.5 Biological reference points... 17 4.6 Management plans... 18 4.7 Uncertainties and bias in assessment and forecast... 18 4.8 Recommendations for next Benchmark... 19 4.9 Management considerations... 20 4.10 References... 20 5 Cod in Division 6.a... 47 5.1 Introduction... 47 5.2 General... 47 5.3 Data... 49 5.3.1 Stock assessment... 52 5.3.2 Short-term stock projections... 55 5.3.3 Reference points... 55 5.3.4 Management plans... 56 5.3.5 Uncertainties and bias in assessment and forecast... 56 5.3.6 Recommendation for next Benchmark... 58 5.3.7 Management considerations... 58 5.3.8 Frequency of assessment... 59 5.4 Sources... 59
ii ICES WGCSE REPORT 2017 6 Cod in Division 27.6.b... 119 6.1 General... 119 6.2 Data... 120 6.3 References... 121 7 Cod in 7.a (Irish Sea)... 128 7.1 General... 128 7.2 Data... 130 7.3 Historical stock development... 132 7.4 Short-term predictions... 133 7.5 Biological reference points... 133 7.6 Management plans... 134 7.7 Uncertainties and bias in assessment and forecast... 134 7.8 Management considerations... 135 7.9 References... 135 7.10 Audit of Cod 27.7a... 191 8 Cod in Divisions 7.bc... 195 9 Cod in Division 7.e k (Celtic Sea)... 197 9.1 General... 197 9.2 Data... 200 9.3 Stock assessment... 202 9.4 Short-term projections... 203 9.5 Medium-term projection... 204 9.6 Biological reference points... 204 9.7 Management plans... 205 9.8 Uncertainties and bias in assessment and forecast... 205 9.9 Management considerations... 206 9.10 References... 206 9.11 Audit of Cod 27.7.e k... 252 10 Haddock in Division 6.b (Rockall)... 253 10.1.1 General... 253 10.1.2 Data... 255 10.1.3 Description of stock assessment approach... 257 10.1.4 Short-term projections... 260 10.1.5 MSY evaluations and biological reference points... 261 10.1.6 Management plans... 262 10.1.7 Uncertainties and bias in assessment and forecast... 263 10.1.8 Recommendation for next benchmark... 263 10.1.9 Management considerations... 264 10.1.10 References... 264
ICES WGCSE REPORT 2017 iii 11 Haddock in Division 7.a... 316 11.1 General... 316 11.2 Data 318 11.3 Historical stock development... 321 11.4 Short-term projections... 323 11.5 Biological reference points... 323 11.6 Management plans... 324 11.7 Uncertainties and bias in assessment and forecast... 324 11.8 Recommendations for next benchmark assessment... 325 11.9 References... 325 11.10 Audit of Haddock in the Irish Sea (had.27.7.a)... 347 12 Haddock in Divisions 7.b,c,e k... 349 12.1 General... 349 12.1.1 Information from the industry... 351 12.1.2 Data... 351 12.1.3 Historical stock development... 353 12.1.4 Short-term projections... 354 12.1.5 MSY evaluations and biological reference points... 355 12.1.6 Management plans... 355 12.1.7 Uncertainties and bias in assessment and forecast... 355 12.1.8 Recommendation for next benchmark... 357 12.1.9 Management considerations... 358 12.1.10 References... 358 13 Megrim in 4.a and 6.a (Northern North Sea and West of Scotland)... 393 13.1 General... 393 13.2 Estimation of survey cpue indices... 396 13.3 Stock assessment... 397 13.4 Short-term projections... 397 13.5 Biological reference points... 398 13.6 References... 399 14 Megrim (Lepidorhombus ssp.) in Division 6.b (Rockall)... 420 14.1 Uncertainties and bias in assessment and forecast... 422 14.2 Recommendation for next Benchmark... 423 14.3 References... 423 15 Norway lobster (Nephrops norvegicus) in Division 6.a, Functional Unit 11 (West of Scotland, North Minch)... 429 15.1 General... 429 15.2 Data available... 431 15.3 Assessment... 433 15.4 Catch option table... 434
iv ICES WGCSE REPORT 2017 15.5 Reference points... 434 15.6 Management strategies... 435 15.7 Quality of assessment and forecast... 435 15.8 Recommendation for next benchmark... 436 15.9 Management considerations... 436 15.10 References... 437 16 Norway lobster (Nephrops norvegicus) in Division 6.a, Functional Unit 12 (West of Scotland, South Minch)... 459 16.1 General... 459 16.2 Data available... 460 16.3 Assessment... 463 16.4 Catch option table... 463 16.5 Reference points... 464 16.6 Management strategies... 464 16.7 Quality of assessment and forecast... 465 16.8 Recommendation for next benchmark... 466 16.9 Management considerations... 466 16.10 References... 467 16.11 Audit of nep.fu.12... 481 17 Norway lobster (Nephrops norvegicus) in Division 6.a, Functional Unit 13 (West of Scotland, the Firth of Clyde and Sound of Jura)... 484 17.1 General... 484 17.2 Data available... 486 17.3 Assessment... 489 17.4 Catch option table... 489 17.5 Reference points... 490 17.6 Management strategies... 491 17.7 Quality of assessment and forecast... 491 17.8 Recommendation for next benchmark... 492 17.9 Management considerations... 492 17.10 References... 493 17.11 Audit of nep.fu.13... 510 18 Norway lobster (Nephrops norvegicus) in Division 7.a, Functional Unit 14 (Irish Sea, East)... 513 18.1 Nephrops Subarea 7 general section... 513 18.1.1 General... 520 18.1.2 Data... 522 18.1.3 Assessment... 525 18.1.4 Catch option table... 526 18.1.5 Reference points... 526
ICES WGCSE REPORT 2017 v 18.1.6 Management strategies... 527 18.1.7 Quality of assessment and forecast... 527 18.1.8 Recommendation for next benchmark... 527 18.1.9 Management considerations... 528 18.1.10 References... 528 18.2 Audit of Nephrops in Division 7.a (Irish Sea East, FU14)... 542 19 Norway lobster (Nephrops norvegicus) in Division 7.a, Functional Unit 15 (Irish Sea, West)... 545 19.1 General... 545 19.2 Data... 546 19.3 Assessment... 549 19.4 Catch option table... 549 19.5 Reference points... 550 19.6 Management strategy... 550 19.7 Quality of assessment and forecast... 550 19.8 Recommendations for next benchmark... 551 19.9 Management considerations... 551 19.10 References... 552 19.11 Audit of nep.fu.15... 569 20 Norway lobster (Nephrops norvegicus) in divisions 7.b c and 7.j k, Functional Unit 16 (west and southwest of Ireland, Porcupine Bank)... 571 20.1 General... 571 20.2 Closed area restrictions... 574 20.3 Fishery in 2016... 575 20.4 Data... 576 20.5 Stock assessment... 579 20.6 Reference points... 580 20.7 Management strategies... 580 20.8 Quality of assessment and forecast... 580 20.9 Recommendation for next benchmark... 580 20.10 Management considerations... 580 20.11 References... 581 21 Norway lobster (Nephrops norvegicus) in Division 7.b, Functional Unit 17 (west of Ireland, Aran grounds)... 596 21.1 General... 596 21.2 Data... 597 21.3 Assessment... 599 21.4 Catch option table... 599 21.5 Reference points... 600 21.6 Management strategies... 600
vi ICES WGCSE REPORT 2017 21.7 Quality of assessment and forecast... 600 21.8 Recommendation for next benchmark... 601 21.9 Management considerations... 601 21.10 References... 601 22 Norway lobster (Nephrops norvegicus) in divisions 7.a, 7.g, and 7.j, Functional Unit 19 (Irish Sea, Celtic Sea, eastern part of southwest of Ireland)... 621 22.1 General... 621 22.2 Data... 622 22.3 Assessment... 625 22.4 Catch option table... 626 22.5 Reference points... 626 22.6 Management strategies... 627 22.7 Quality of assessment and forecast... 627 22.8 Recommendations for next benchmark... 627 22.9 Management considerations... 628 22.10 References... 628 23 Norway lobster (Nephrops norvegicus) in divisions 7.g and 7.h, functional units 20 and 21 (Celtic Sea)... 648 23.1 General... 648 23.2 Data... 650 23.3 Assessment... 653 23.4 Catch options table... 654 23.5 Reference points... 654 23.6 Management plans... 655 23.7 Quality of assessment and forecast... 655 23.8 Recommendations for next benchmark... 655 23.9 Management considerations... 656 23.10 References... 656 24 Norway lobster (Nephrops norvegicus) in divisions 7.g and 7.f, Functional Unit 22 (Celtic Sea, Bristol Channel)... 674 24.1 General... 674 24.2 Data... 676 24.3 Assessment... 678 24.4 Catch options table... 679 24.5 Reference points... 679 24.6 Management strategies... 680 24.7 Quality of assessment and forecast... 680 24.8 Recommendation for next benchmark... 681 24.9 Management considerations... 681
ICES WGCSE REPORT 2017 vii 24.10 References... 681 24.11 Audit of Nephrops FU22 (Smalls Grounds)... 696 25 Plaice in Division 27.7.a (Irish Sea)... 697 25.1 General... 697 25.2 Data... 699 25.3 Historical stock development... 701 25.4 Short-term projections... 704 25.5 Medium-term projections... 705 25.6 MSY explorations... 706 25.7 Management plans... 706 25.8 Uncertainties and bias in assessment and forecast... 706 25.9 Recommendations for next benchmark... 706 25.10 Management considerations... 707 25.11 Sources... 707 26 Plaice in 7.bc (West of Ireland)... 737 26.1 General... 737 27 Plaice in the Western Channel (ICES Division 7.e)... 741 27.1 General... 741 27.1.1 Data-limited methods... 749 27.1.2 Stock assessment... 751 27.1.3 Short-term projections... 755 27.1.4 Biological reference points... 756 27.1.5 Management plans... 756 27.1.6 Uncertainties and bias in assessment and forecast... 757 27.1.7 Recommendations for next Benchmark... 757 27.1.8 Management considerations... 758 27.2 References... 759 27.3 Audit of Plaice in 7.e... 783 27.4 WKProxy review of WGCSE Ple.27.7e, Plaice (Pleuronectes platessa) in Division 7.e (Western English Channel)... 784 28 Plaice in Divisions 7.f g (Celtic Sea)... 786 28.1 Type of assessment in 2017... 786 28.2 Data... 787 28.3 Stock assessment... 790 28.4 Short-term projections... 792 28.5 Precautionary approach reference points... 792 28.6 Management plans... 792 28.7 Uncertainties in assessment and forecast... 793 28.8 References... 793
viii ICES WGCSE REPORT 2017 28.9 WKProxy review of WGCSE Ple.27.7.fg (ple-celt) Plaice (Pleuronectes platessa) in divisions 7.f and 7.g (Bristol Channel, Celtic Sea)... 824 29 Plaice in the southwest of Ireland (ICES Divisions 7.h k)... 826 29.1 General... 826 29.2 Data... 827 29.3 Historical stock development... 828 29.4 MSY evaluation... 829 29.5 Uncertainties and bias in the assessment and forecast... 831 29.6 Recommendations for the next benchmark... 832 29.7 Management considerations... 832 29.8 References... 832 29.9 Audit of plaice in Division 7.h k (ple-7h k)... 854 30 Pollack in the Celtic Seas (ICES subareas 6 and 7)... 855 30.1 General... 855 30.1.1 Stock Identity... 855 30.1.2 Management applicable to 2018... 855 30.1.3 Biology... 856 30.1.4 The fisheries... 857 30.1.5 Surveys... 857 30.2 Data... 857 30.2.1 Landings... 857 30.3 MSY explorations... 858 30.3.1 DCAC model... 858 30.3.2 Other DLS methods explorations... 859 30.3.3 SPiCT... 859 30.3.4 Length-based indicators and reference points: LBI methods... 860 30.3.5 Mean length-based mortality estimators... 860 30.4 Uncertainties in assessment and forecast... 861 30.5 Ecosystem considerations... 861 30.6 Management considerations... 861 30.7 References... 862 31 Seabass (Dicentrarchus labrax) in divisions 4.b c, 7.a, and 7.d h (central and southern North Sea, Irish Sea, English Channel, Bristol Channel, and Celtic Sea)... 879 31.1 General... 880 31.1.1 Management applicable to 2015... 881 31.1.2 Management applicable to 2016... 882 31.1.3 Management applicable to 2017... 882 31.1.4 Fishery in 2016... 883 31.2 Data... 884 31.2.1 Landings data... 884
ICES WGCSE REPORT 2017 ix 31.2.2 Length compositions: commercial landings... 884 31.2.3 Sampling rates... 885 31.2.4 Length composition estimates for landings... 885 31.2.5 Age composition estimates for landings... 885 31.2.6 Commercial discards... 886 31.2.7 Recreational catches... 887 31.2.8 Biological data... 891 31.2.9 Survey data used in assessment... 897 31.2.10 Commercial landings per unit of effort... 899 31.2.11 Other relevant data... 899 31.3 Stock assessment... 900 31.3.1 Model structure and input data / parameters for update assessment... 900 31.3.2 Retrospective analyses... 902 31.3.3 Final update assessment: long-term trends... 902 31.3.4 Comparison with previous assessments... 902 31.3.5 The state of the stock... 903 31.3.6 Sensitivity of the final update assessment to data and assumptions... 903 31.4 Biological reference points... 904 31.5 Short-term predictions... 905 31.5.1 Recruiting year-class strength... 905 31.5.2 Numbers of fish in 2016... 906 31.5.3 F-at-age vectors... 906 31.5.4 Weights-at-age... 906 31.5.5 Maturity ogive... 906 31.5.6 Detailed short-term forecast output at status quo F... 906 31.5.7 Management options... 907 31.6 Uncertainties and bias in assessment and forecast... 907 31.6.1 Landings and discards data... 907 31.6.2 Fishery composition data... 907 31.6.3 Recreational fishery harvests... 908 31.6.4 Surveys... 908 31.6.5 Commercial lpue indices... 909 31.6.6 Model formulation... 910 31.6.7 Stock structure and migrations... 910 31.6.8 Biological parameters... 910 31.6.9 Intermediate year fishing mortality and catch levels for forecasts... 910 31.7 Recommendations for completion of the 2017 benchmark assessment... 911 31.7.1 Full benchmark of NE Atlantic sea bass stocks... 911 31.7.2 Management considerations... 911 31.8 References... 913 32 European sea bass in divisions 6.a, 7.b and 7.j (West of Scotland and Ireland)... 985
x ICES WGCSE REPORT 2017 33 Sole in Division 7.a (Irish Sea)... 990 33.1 General... 991 33.2 Stock assessment... 996 33.3 Short-term projections... 997 33.4 MSY explorations... 997 33.5 Biological reference points... 998 33.6 Management plans... 998 33.7 Uncertainties and bias in assessment and forecast... 999 33.8 Recommendations for next Benchmark... 1000 33.9 Management considerations... 1000 33.10 Ecosystem considerations... 1001 33.11 References... 1001 34 Sole in West of Ireland Division 7.bc... 1031 34.1 General... 1031 35 Sole in Division 7.e... 1037 35.1 General... 1037 35.2 Data... 1039 35.3 Stock assessment... 1043 35.4 Short-term projections... 1046 35.5 Biological reference points... 1046 35.6 Management plan... 1047 35.7 Uncertainties in assessment and forecast... 1047 35.8 Recommendation for the next benchmark... 1049 35.9 Management considerations... 1049 35.10 Ecosystem considerations... 1050 35.11 Regulations and their effects... 1050 35.12 Changes in fishing technology and fishing patterns... 1050 35.13 Changes in the environment... 1050 35.14 References... 1050 35.15 Audit of Sole in 7.e... 1095 36 Sole in divisions 7.f and 7.g... 1114 36.1 General... 1115 36.2 Data... 1116 36.3 Stock assessment... 1118 36.4 Short-term projections... 1120 36.5 MSY explorations... 1121 36.6 Biological reference points... 1122 36.7 Management plans... 1123 36.8 Uncertainties and bias in assessment and forecast... 1123
ICES WGCSE REPORT 2017 xi 36.9 Recommendation for next Benchmark... 1124 36.10 Management considerations... 1124 36.11 Ecosystem considerations... 1125 36.12 References... 1125 37 Sole in the Southwest of Ireland (ICES Divisions 7.h k)... 1175 37.1 General... 1175 37.2 Data... 1176 37.3 Historical stock assessment development... 1177 37.4 MSY evaluation... 1178 37.5 Uncertainties and bias in the assessment and forecast... 1180 37.6 Recommendations for the next benchmark... 1180 37.7 Management considerations... 1180 37.8 References... 1180 37.9 Audit of sole in divisions 7. h-k... 1202 37 Sole in the Southwest of Ireland (ICES Divisions 7.h k)... 1175 37.1 General... 1175 37.2 Data... 1176 37.3 Historical stock assessment development... 1177 37.4 MSY evaluation... 1178 37.5 Uncertainties and bias in the assessment and forecast... 1180 37.6 Recommendations for the next benchmark... 1180 37.7 Management considerations... 1180 37.8 References... 1180 37.9 Audit of sole in divisions 7. h-k... 1202 38 Whiting in Division 27.6.a... 1203 38.1 General... 1203 38.2 Data... 1204 38.3 Historical stock development... 1207 38.4 Short-term projections... 1209 38.5 MSY explorations... 1209 38.6 MSY and Biological reference points... 1209 38.7 Management plans... 1210 38.8 Uncertainties and bias in the assessment and forecast... 1210 38.9 Recommendation for next benchmark... 1210 38.10 Management considerations... 1211 38.11 References... 1211 38.12 Audit of wgh-scow (Division 27.6.a)... 1252 39 Whiting in Division 27.6.b... 1253
xii ICES WGCSE REPORT 2017 39.1 General... 1253 39.2 Data... 1254 39.3 Target category... 1254 39.4 Management considerations... 1255 39.1 Audit of whg-rock (Division 27.6b)... 1261 40 Whiting in 7.a... 1262 40.1 General... 1262 40.2 Information from the Industry... 1264 40.3 Data... 1264 40.4 Historical stock development... 1266 40.5 Short-term predictions... 1266 40.6 Medium-term projection... 1267 40.7 MSY evaluations and Biological Reference Points... 1267 40.8 Management plans... 1267 40.9 Uncertainties and bias in assessment and forecast... 1267 40.10 Recommendations for next benchmark assessment... 1269 40.11 Management considerations... 1269 40.12 References... 1269 41 Whiting in Division 7.b, c, e k... 1311 41.1 General... 1311 41.2 The fishery in 2016... 1312 41.3 Data... 1313 41.4 Historical stock development... 1315 41.5 Short-term projections... 1316 41.6 MSY evaluations and Biological reference points... 1316 41.7 Management plans... 1317 41.8 Uncertainties and bias in assessment and forecast... 1317 41.9 Recommendation for next benchmark... 1318 41.10 Management considerations... 1318 41.11 References... 1319 41.12 Tables... 1320 41.13 Figures... 1342 41.14 Audit of Whiting (Merlangius merlangus) in Divisions 7.b, c, and e k (Southern Celtic seas and Eastern English Channel)... 1354 Annex 1: Participants list... 1356 Annex 2: WGCSE Stock Annexes... 1361 Annex 3: Working Documents presented to WGCSE 2017... 1366
ICES WGCSE REPORT 2017 xiii Annex 4: Technical Minutes of the Review Group for the Review Group of Celtic Sea Stocks (RGCS)... 1413
ICES WGCSE REPORT 2017 1 Executive Summary The ICES Working Group for the Celtic Seas Ecoregion (WGCSE) met from 9th 18th May 2017 at ICES Headquarters in Copenhagen. The participants were from five countries; Belgium, France, Ireland, the Russian Federation and the UK. Of the 29 participants, 14 attended all of the meeting, eight attended part-time, and seven contributed by correspondence. The WG was supported throughout by a professional from ICES secretariat who assisted the WG with their advice drafting tasks. The meeting was chaired by Tim Earl and Helen Dobby (UK). In total the WG is responsible for the provision of updated fisheries data, assessments and draft advice for 39 demersal fish and Nephrops stocks across ICES subareas 6 and 7 (with the distribution of megrim extending into Division 4.a, sea bass into 4.b,c and anglerfish into Subarea 4 and Division 3.a). This includes twelve Nephrops stocks, five sole and plaice stocks, four cod and whiting stocks, three haddock stocks, two each of megrim and sea bass, one anglerfish and one putative pollock stock. As in previous years, advice for Nephrops, anglerfish and Rockall megrim is not issued until autumn to make use of the most up to date survey information. Advice for sea bass has been delayed until autumn this year, to allow changes in the assessment data to be fully reviewed. Advice from the remaining stocks was scheduled for release on the 30th June. Since the last Working Group meeting five stocks have gone through an Interbenchmark procedure; cod.27.7.a, had.27.7.a, ple.27.7.a, whg.27.7.a and bss.27.4.b.c7.a.d h the results of which were presented to the group. The Working Group considered reference points for all category 3 and 4 stocks. Update assessments were generally carried out according to the stock annexes (any deviations were detailed in the stock sections). Overall the stock status across the ecoregion shows a slight improvement relative to that presented last year. Of the 39 stocks assessed, 20 were fished below FMSY and 18 were above MSY Btrigger, ten stocks were fished above FMSY and ten were below MSY Btrigger, nine stocks had unknown status relative to FMSY and eleven relative to Btrigger (see table below). Number of stocks relative to reference points by WG year: 2011 2012 2013 2014 2016 2017 F Below FMSY 17 11 14 16 19 20 F Above FMSY 9 14 13 11 10 10 Unknown 10 11 12 12 10 9 2011 2012 2013 2014 2016 2017 SSB Above Btrigger 13 13 11 13 15 18 SSB Below Btrigger 5 4 5 7 11 10 Unknown 18 19 23 19 13 11
2 ICES WGCSE REPORT 2017 West of Scotland cod remains severely depleted, but the Nephrops stocks within functional units 11 13 and megrim in divisions 6.a and 4.a are exploited below FMSY and have biomass or abundance above MSY Btrigger. The assessment of Northern Shelf anglerfish stock also shows an increase in stock size and decrease in harvest rate, although reference points have not been defined for this stock. In the Irish Sea, the WKIrish benchmark has resulted in an upgrading of the assessments for haddock, plaice and whiting from category 3 to category 1, and the adoption of a model for cod that allows forecasts to be performed. Sole remains below Blim, but fishing is below Flim, and there are initial signs of increasing biomass and recruitment. Whiting in 7.a remains at a very low level relative to the past and remains severely depleted. Cod, haddock and plaice biomass are above possible reference points and increasing. The two Nephrops stocks FU15 and FU14 are above Btrigger. FU14 and below FMSY. Further south, in the Celtic Sea and West of Ireland areas, the biomass of haddock and whiting stocks have been at a high level well above MSY Btrigger in recent years following some high or moderate recruitment. The cod stock is slightly below Blim, but forecast to increase above Blim during 2017, despite fishing pressure being consistently above FMSY. Among the Nephrops stocks in this area, three stocks are below MSY Btrigger: functional units 17, 19 and 22, and the remaining have no biomass reference points. Functional units 16, 19 and 20 21 are estimated to be exploited below FMSY, while the remaining functional units are above FMSY. Celtic Sea sole is now assessed as being fished above FMSY although the SSB remains above MSY Btrigger. Reference points were adopted at the Working Group for ple.27.7.fg, ple.27.7.h k and sol.27.7.h k. Both sol.27.7.h k and ple.27.7.fg are above MSY Btrigger and below FMSY, whereas ple.27.7.h k is below Blim and fishing pressure remains above Flim. The assessment for sea bass in 4.b.c, 7.a and 7.d h could not be updated at WGCSE 2017 due to a substantial revision to the calculation of lpue data used as tuning for the assessment.
ICES WGCSE REPORT 2017 3 1 Introduction 1.1 Terms of reference 1.1.1 Generic ToRs 2016/2/ACOM05 The following ToRs apply to: AFWG, HAWG, NWWG, NIPAG, WGWIDE, WGBAST, WGBFAS, WGNSSK, WGCSE, WGDEEP, WGBIE, WGEEL, WGEF, WGHANSA and WGNAS. The working group should focus on a ) Consider and comment on ecosystem and fisheries overviews where available; b ) For the aim of providing input for the Fisheries Overviews, consider and comment for the fisheries relevant to the working group on: i ) descriptions of ecosystem impacts of fisheries ii ) descriptions of developments and recent changes to the fisheries iii ) mixed fisheries overview, and iv ) emerging issues of relevance for the management of the fisheries; c ) Conduct an assessment to update advice on the stock(s) using the method (analytical, forecast or trends indicators) as described in the stock annex and produce a brief report of the work carried out regarding the stock, summarising where the item is relevant: i ) Input data and examination of data quality; ii ) Where misreporting of catches is significant, provide qualitative and where possible quantitative information and describe the methods used to obtain the information; iii ) For relevant stocks (i.e. all stocks with catches in the NEAFC area) estimate the percentage of the total catch that has been taken in the NEAFC Regulatory Area in the last year. iv ) The developments in spawning stock biomass, total stock biomass, fishing mortality, catches (wanted and unwanted landings and discards) using the method described in the stock annex; v ) The state of the stocks against relevant reference points; vi ) Catch options for next year; vii ) Historical performance of the assessment and catch options and brief description of quality issues with these; d ) Produce a first draft of the advice on the fish stocks and fisheries under considerations according to ACOM guidelines. e ) Review progress on benchmark processes of relevance to the expert group; f ) Prepare the data calls for the next year update assessment and for the planned data evaluation workshops; g ) Identify research needs of relevance for the expert group. Information of the stocks to be considered by each Expert Group is available here.
4 ICES WGCSE REPORT 2017 1.1.2 Specific ToRs 2016/2/ACOM13 The Working Group for the Celtic Seas Ecoregion (WGCSE), chaired by Timothy Earl, UK and Helen Dobby, Scotland, UK will meet at ICES Headquarters, Copenhagen, Denmark, 9 18 May 2017 and by correspondence September / October 2017 to: a ) Address generic ToRs for Regional and Species Working Groups; b ) Report on reopened advice if appropriate; c ) Estimate MSY proxy reference points for the category 3 and 4 stocks in need of new advice in 2017 (see table below). i ) Collate necessary data and information for the stocks listed below prior to the Expert Group meeting. An official ICES data call was made for length and select life-history parameters for each stock in the table below; ii ) Propose appropriate MSY proxies for each of the stocks listed below by using methods provided in the ICES Technical Guidelines (i.e. peer reviewed methods that were developed by WKLIFE V, WKLIFE VI, and WKProxy) along with available data and expert judgement. Stock Code Stock name description EG Data Category anf.27.3a46 Anglerfish (Lophius piscatorius and L. budegassa) in subareas 4 and 6, and in Division 3.a (North Sea, Rockall and West of Scotland, Skagerrak and Kattegat) WGCSE 3 had.27.7a Haddock (Melanogrammus aeglefinus) in Division 7.a (Irish Sea) WGCSE 3.2 lez.27.6b Megrim (Lepidorhombus spp.) in Division 6.b (Rockall) WGCSE 3 nep.fu.2021 Norway lobster (Nephrops norvegicus) in divisions 7.g and 7.h, functional units 20 and 21 (Celtic Sea) WGCSE 4 ple.27.7a Plaice (Pleuronectes platessa) in Division 7.a (Irish Sea) WGCSE 3.2 ple.27.7e ple.27.7fg ple.27.7h k pol.27.67 sol.27.7h k Plaice (Pleuronectes platessa) in Division 7.e (western English Channel) Plaice (Pleuronectes platessa) in divisions 7.f and 7.g (Bristol Channel, Celtic Sea) Plaice (Pleuronectes platessa) in divisions 7h k (Celtic Sea South, southwest of Ireland) Pollack (Pollachius pollachius) in subareas 6 7 (Celtic Seas and the English Channel) Sole (Solea solea) in divisions 7.h k (Celtic Sea South, southwest of Ireland) WGCSE 3.2 WGCSE 3.2 WGCSE 3.2 WGCSE 4.12 WGCSE 3.2 whg.27.7a Whiting (Merlangius merlangus) in Division 7.a (Irish Sea) WGCSE 3.14 The assessments will be carried out on the basis of the stock annex. The assessments must be available for audit on the first day of the meeting. Material and data relevant for the meeting must be available to the group no later than 25 April 2017 according to the Data Call 2017.
ICES WGCSE REPORT 2017 5 WGCSE will report by 25 May 2017 for the attention of ACOM, and by 7 October 2017 for Nephrops stocks, anglerfish and megrim in Rockall. Concerning ToR b) the group will report on the ACOM guidelines on reopening procedure of the advice before 12 October and will report on reopened advice before 28 October. 1.1.3 Additional ToR The Workshop on the Development of the ICES approach to providing MSY advice for category 3 and 4 stocks (WKMSYCat34) met on 6 to 10 March 2017. One of the ToRs was Defining a set of criteria for the identification of category 3 and 4 stocks that should be candidates for full analytical assessment with forecast, and identifying some candidate stocks. In response to this ToR, WKMSYCat34 developed a template to evaluate if a stock could be a candidate for a full analytical assessment with forecast (i.e. category 1) after a benchmark-type or similar process. The template was tested on three example stocks and was found to provide the necessary information to identify the potential candidate stocks. WKMSYCat34 recommended that the template be used by the stock assessment expert groups in 2017 to identify candidate stocks for category 1. Below I have included the relevant chapter of the WKMSYCat34 report. The ACOM leadership has discussed the recommendation and agrees that the template is a useful tool to identify candidate category 3 and 4 stocks for full analytical assessment. The leadership also supports the recommendation to request stock assessment groups to apply the template. The ACOM leadership is aware that adding a new ToR to your group at this stage is not optimal and that it may be difficult to find time to address the request. However, the input from your group is crucial to be able to move forward with this. For this reason, I would like to request that you read the chapter below from the WKM- SYCat34 report and consider to what extent your group will be able to apply (fully or partly) the template for category 3 and 4 stocks assessed by your group. 1.2 Participation The number of participants able to attend the Working Group for the full duration of the meeting continues to decline (Figures 1.2.1 and 1.2.2) but this year showed an increase in the total number of people participating due to an increase in numbers participating part-time (this includes members working by correspondence). As last year, seven institutes were represented by full-time participants at the meeting.
6 ICES WGCSE REPORT 2017 Figure 1.2.1. Numbers of WGCSE full-time participants by institute over time. Figure 1.2.2. Numbers of WGCSE participants over time and whether they were full-time or parttime (part-time includes working by correspondence).
ICES WGCSE REPORT 2017 7 Figure 1.2.3. Number of participants in WGCSE 2017 by day. 1.3 Methods The type of final assessments presented at the WG are summarised as follows: Category 1 age-based assessments and forecasts were conducted for cod.27.6.a, cod 27.7.a, cod.27.7.e k, had.27.6.b, had.27.7.a, had.27.7.b k, ple.27.7.a, sol.27.7.a, sol.27.7.fg, sol.27.7.e, whi.27.6.a, whi.27.7.a, whg.27.7.b ce k; Category 1 Bayesian surplus production model for lez.27.4.a6.a; Category 1: UWTV survey based assessments and advice were used for nep.fu.11, nep.fu.12, nep.fu.13, nep.fu.14, nep.fu.15, nep.fu.16, nep.fu.17, nep.fu.19, nep.fu.2021 and nep.fu.22. Fisheries data were updated at the May meeting and survey data were updated in the autumn. Category 3: Catch-at-age based assessments with caveats i.e. used for trends only and without forecasts for ple.27.7.e, ple.27.7.h k and sol.27.7.h k. Category 3: Assessments based on survey data (Surba model or survey index) are used as the assessment and advice basis for anf.27.3a46, lez.27.6b, and ple.27.7fg. Category 4: Depletion corrected average catch was used for pol.27.67. Category 5 & 6: No assessments were carried out in 2016 for bss.27.6bc7ad h, ple.27.7bc, sol.27.7bc, cod.6b, whi.27.6b, nep.27.6aoutfu and nep.27.7outfu; only landings statistics were updated. No assessment could be performed at the working group for bss.27.4bc7ad h due to changes in the calculation of the lpue index, which the Working Group considered needed an external review. For the stocks for which a full analytical assessment was possible, the WG typically used either Extended Survivor s Analysis (XSA), Time-Series Analysis (TSA), or Age- Structured Assessment Program (ASAP). These approaches and procedures for using them are discussed in further detail in the relevant stock annexes.
8 ICES WGCSE REPORT 2017 1.4 Internal auditing and external reviews This year ICES reinstated the external review process, establishing a Review Group (RG) with the responsibility of auditing all category 1 stocks ahead of the ADG. No major errors were detected by this process, but the RG did provide some useful comments to be considered in next year s assessments. In addition, the WG again carried out its own internal audit process using the standard ICES template. Stocks audited by the WG included: cod.27.6b, cod.27.7a, cod.27.7e k, had.27.7a, had.27.7b k, ple.27.7e, ple.27.7fg, sol.27.7bc, sol.27.7e, sol.27.7fg, sol.27.7h k, whg.27.6a, whg.27.6b, whg.27.7bce k. Given the workload of many of the scientists at WGCSE (sometimes with one scientist responsible for two or more stocks), many of the reports were not finalized until after the WG meeting. Audits were therefore typically carried out by correspondence after the WG and not completed for some stocks. Lack of thorough review (due to time pressures) for a number of more minor category 3 stocks resulted in assessment errors being identified at the ADG and assessments and having to be re-run as a result. 1.5 ToR e WGCSE recommendations for stocks to be benchmarked WGCSE recommend that cod, haddock and whiting in the Celtic Sea should be benchmarked together in 2018, and that sole in the Celtic Sea, haddock in Rockall, anglerfish in 3a46 should also be benchmarked in 2018. The WG also agreed that there is a need to benchmark both West of Scotland whiting and West of Scotland cod in the near future. However, given the issues associated with stock structure (for cod in particular), it may be appropriate to conduct West of Scotland and North Sea cod benchmarks concurrently. The focus of the benchmarks would be on streamlining data compilation procedures for fishery-dependent and survey data. This will give improved transparency and diagnostics surrounding commercial tuning fleets and surveys. The benchmark should also relook at the assessment methods and diagnostics given the potential for changes in selectivity in the commercial fishery. The benchmark should also investigate mixed fisheries and multispecies interactions as well as environmental drivers that may be impacting on growth and recruitment of all three species. Further details are given in the stock sections. 1.6 ToR c(ii) Estimation of MSY proxy reference points The Terms of reference contained a list of eleven stocks for which proxy reference points should be considered. The Working Group addressed this Tor as follows. For three stocks (haddock, plaice and whiting in the Irish Sea), the WKIrish benchmark had already addressed this issue by calculating reference point based on category 1 assessments, and the results were presented to the Working Group and adopted. For three stocks (plaice in 7.e and in 7.h k, sole in 7.h k) age-based assessments are performed, although only used as relative indicators of stock status. For these stocks, reference points were estimated using the package EqSim, and the method of WKMSYREF4. For pollack in subareas 6 7, the current DCAC assessment provides indication of whether the stock is being exploited below FMSY. But no indication of a how biomass compares to any reference point. Alternative proxies using length-based methods and SpiCT were presented to the Working
ICES WGCSE REPORT 2017 9 Group, but judged to be unsatisfactory, and so the DCAC estimation was used. For plaice in 7.fg, a SpiCT assessment using survey and lpue data, combined with a hind-cast of discards was used to estimate the stock status relative to reference points. For Nephrops in functional units 20 21, proxy reference already exist, and there were no alternative approaches proposed. For megrim in Rockall, the majority of work for this stock is completed later in the year in time for Autumn advice. For anglerfish in subareas 4 & 6, none of the DL approaches for estimating proxy reference points proved entirely satisfactory. This stock is scheduled to be benchmarked in 2018, and so the work of finding suitable reference points was deferred until the assessment has been reviewed. 1.7 Completion of checklist for upgrading category 3 and 4 stocks To address the additional ToR regarding completing the checklist for upgrading the category 3 and 4 stocks, the following progress was made: For plaice in 7.e and anglerfish in subareas 4 & 6 a checklist was completed and is included in this report in the relevant sections. For and plaice in 7.fg, which are planned to be benchmarked this winter, the issues lists were updated, and so the checklist was considered redundant. For plaice in 7.h k, sole in 7.h k, pollock in subareas 6 7, nephrops in functional units 20 21 (which is now a category 1 stock) and megrim in Rockall no checklists were completed.