ICES AFWG REPORT 2017 Report of the Arctic Fisheries Working Group

502 Pages·2017·25.14 MB·English

ICES AFWG REPORT 2017

ICES ADVISORY COMMITTEE
ICES CM 2017/ACOM:06
REF. ACOM
Report of the Arctic Fisheries Working Group
(AFWG)
19–25 April 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 [phone]
Telefax ([phone]
www.ices.dk
[email protected]
Recommended format for purposes of citation:
ICES. 2017. Report of the Arctic Fisheries Working Group (AFWG), 19–25 April 2017,
Copenhagen, Denmark. ICES CM 2017/ACOM:06. 493 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.
© 2017 International Council for the Exploration of the Sea
ICES AFWG REPORT 2017 | i
Contents
Executive summary.................................................................................................. 1
0 Introduction ..................................................................................................... 3
0.1 Terms of reference .................................................................................. 3
0.2 Responses to Terms of Reference ......................................................... 5
0.3 Unreported landings, discards, bycatch and uncertainties in the
catch data................................................................................................. 5
0.3.1 Total catches ............................................................................... 5
0.3.2 Uncertainty in catch data ......................................................... 6
0.3.3 Sampling effort– commercial fishery...................................... 6
0.4 Uncertainties in survey data ................................................................. 8
0.5 Age reading ............................................................................................. 9
0.6 Assessment method issues.................................................................. 12
0.7 Environmental included in advice of NEA cod ............................... 12
0.8 Proposals for status of assesments in 2018–2019 ............................. 12
0.9 Stock annexes ........................................................................................ 13
0.10 Audit reports ........................................................................................ 13
0.11 InterCatch .............................................................................................. 13
0.12 The percentage of the total catch that has been taken in the NEAFC
regulatory areas by year in the last year ........................................... 14
0.13 Relationship to WGIBAR .................................................................... 15
0.14 Research needs of relevance for the Working Group ..................... 15
0.15 Recommendations ................................................................................ 16
0.16 Time and place of Next Meeting ........................................................ 16
1 Ecosystem information ................................................................................. 32
1.1 0-group abundance .............................................................................. 32
1.2 Consumption, natural mortality and growth ................................... 32
1.3 Maturation, condition factor and fisheries–induced evolution ..... 33
1.4 Recruitment prediction for Northeast Arctic cod ............................ 34
1.5 Biomass and exploration levels of AFWG stocks. ........................... 37
2 Cod in subareas 1 and 2 (Norwegian coastal waters) ............................. 53
2.1 Stock status summary .......................................................................... 53
2.2 Fisheries ................................................................................................. 53
2.2.1 Sampling fisheries and estimating catches (Tables 2.1–2.4,
Figures 2.1–2.5) ........................................................................ 54
2.2.2 Regulations ............................................................................... 55
2.3 Survey data ........................................................................................... 57
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2.3.1 Indices of abundance and biomass (Tables 2.5-2.14, Figures
2.6-2.12) ..................................................................................... 57
2.3.2 Age reading and stock separation (Tables 2.4, 2.5, 2.8-
2.12) ........................................................................................... 57
2.3.3 Weights at age (Table 2.8, Figure 2.13a) ............................... 57
2.3.4 Maturity-at-age (Table 2.10, Figure 2.13b) ........................... 57
2.4 Data available for the Assessment ..................................................... 58
2.4.1 Catch-at-age (Table 2.1 and table 2.14) ................................. 58
2.4.2 Weights at age (Tables 2.8 and 2.13) ..................................... 58
2.4.3 Natural mortality .................................................................... 58
2.4.4 Maturity-at-age (Tables 2.10, 2.13, Figure 2.13) ................... 58
2.5 Methods used for assessing trends in stock size and mortality
(Table 2.13-2.18, Figure 2.16-2.18) ...................................................... 58
2.6 Results of the Assessment ................................................................... 59
2.6.1 Comparing trends with last year’s assessment (Table 2.6,
2.15—2.18, Figures 2.6, 2.13–2.14, 2.16–2.18)........................ 59
2.6.2 Recruitment (Table 2.6, Figure 2.16) ..................................... 60
2.6.3 Catches in 2017 ........................................................................ 60
2.7 Comments to the Assessment ............................................................ 60
2.8 Reference points ................................................................................... 60
2.9 Management considerations ............................................................... 60
2.10 Rebuilding plan for coastal cod .......................................................... 61
2.11 Recent ICES advice .............................................................................. 62
3 North-East Arctic Cod (Subareas 1 and 2)............................................... 113
3.1 Status of the fisheries ......................................................................... 113
3.1.1 Historical development of the fisheries (Table 3.1) .......... 113
3.1.2 Reported catches prior to 2017 (Tables 3.1-3.4, Figure
3.1) ........................................................................................... 113
3.1.3 Unreported catches of Northeast Arctic cod (Tables 3.1) 114
3.1.4 TACs and advised catches for 2016 and 2017 .................... 114
3.2 Status of research ............................................................................... 114
3.2.1 Fishing effort and CPUE (Table A1) ................................... 114
3.2.2 Survey results - abundance and size at age (Tables 3.5, A2-
A14) ......................................................................................... 114
3.2.3 Age reading ............................................................................ 116
3.3 Data used in the assessment ............................................................. 117
3.3.1 Catch at age (Tables 3.6) ....................................................... 117
3.3.2 Weight at age (Tables 3.7 -3.9, A2, A4, A6, A8, A12). ....... 117
3.3.3 Natural mortality including cannibalism (Table 3.12) ..... 118
3.3.4 Maturity at age (Tables 3.10 and 3.11) ................................ 119
3.4 Benchmark and change of assessment model ................................ 119
3.5 Assessment using SAM (Tables 3.13, A13) ..................................... 119
3.5.1 SAM settings (Table 3.14) ..................................................... 120
3.5.2 SAM diagnostics (Figure 3.2a,b,c) ....................................... 120
ICES AFWG REPORT 2017 | iii
3.5.3 Results (Table 3.15-3.18, Figure 3.1) .................................... 120
3.6 Results of the assessment .................................................................. 120
3.6.1 Fishing mortalities and stock biomass (Tables 3.18, 3.20) 120
3.6.2 Recruitment (Table 1.9a)....................................................... 121
3.7 Reference points and harvest control rules .................................... 121
3.7.1 Biomass reference points ...................................................... 121
3.7.2 Fishing mortality reference points ...................................... 121
3.7.3 Harvest control rule .............................................................. 121
3.8 Prediction ............................................................................................ 123
3.8.1 Prediction input (Table 3.19, Figure 3.3-3.6) ...................... 123
3.8.2 Prediction results (Tables 3.20 - 3.21).................................. 124
3.9 Comparison with last year’s assessment ........................................ 125
3.10 Additional assessment methods ...................................................... 125
3.10.1 XSA .......................................................................................... 125
3.10.2 TISVPA (Tables 3.22-3.24) .................................................... 125
3.10.3 Model comparisons ............................................................... 126
3.11 Comments to the assessment ............................................................ 126
3.12 New and revised data sources ......................................................... 126
3.12.1 Consistency between NEA cod and coastal cod catch data
(Table 3.2) ............................................................................... 126
3.12.2 Discard and bycatch data (Tables 3.25-3.26) ...................... 127
3.12.3 Conversion factors ................................................................ 127
4 Northeast Arctic Haddock (Subareas I and II) ....................................... 192
4.1 Status of the Fisheries ........................................................................ 192
4.1.1 Historical development of the fisheries ............................. 192
4.1.2 Landings prior to 2017 (Tables 4.1–4.3, Figure 4.1)........... 192
4.2 Catch advice and TAC for 2017 ........................................................ 193
4.3 Status of Research .............................................................................. 193
4.3.1 Survey results (Tables B1-B5) .............................................. 193
4.4 Weight-at-age (Tables B6 – B9) ......................................................... 193
4.5 Data Used in the Assessment ........................................................... 194
4.5.1 Estimates of unreported catches (Tables 4.1-4.3) .............. 194
4.5.2 Catch-at-age (Table 4.4) ........................................................ 194
4.5.3 Weight-at-age (Tables 4.5–4.6) ............................................. 194
4.5.4 Maturity-at-age (Table 4.7) ................................................... 194
4.5.5 Natural mortality (Tables 4.8) .............................................. 194
4.5.6 Changes in data from last year (Tables 4.6-4.7, B3) .......... 194
4.6 Assessment models and settings...................................................... 195
4.6.1 Data for tuning (Table 4.9) ................................................... 195
4.6.2 SAM model settings (Table 4.10) ......................................... 195
4.7 Results of the Assessments (Tables 4.11–4.15 and Figures 4.1, 4.2,
4.5 and 4.6) .......................................................................................... 195
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4.8 Predictions, reference points and harvest control rules (Tables 4.16-
4.21) ...................................................................................................... 196
4.8.1 Recruitment (Tables 4.16, 4.17) ............................................ 196
4.8.2 Prediction data (Table 4.18) ................................................. 196
4.8.3 Biomass reference points (Figure 4.1) ................................. 196
4.8.4 Fishing mortality reference points (Table 4.21, Figure
4.1) ........................................................................................... 197
4.8.5 Harvest control rule .............................................................. 197
4.8.6 Prediction results and catch options for 2018 (Tables 4.19 -
4.20) ......................................................................................... 197
4.9 Comparison with last year’s assessment ........................................ 198
4.10 Additional assessment methods (Table 4.15, Figure 4.3) .............. 198
4.10.1 XSA .......................................................................................... 198
4.10.2 TISVPA (Figure 4.3) .............................................................. 199
4.10.3 Results (Figure 4.3) ................................................................ 199
4.11 Comments to the assessment ............................................................ 200
5 Saithe in Sub-areas I and II (Northeast Arctic) ...................................... 267
5.1 The Fishery (Tables 5.1.1-5.1.2, Figure 5.1.1) ................................... 267
5.1.1 ICES advice applicable to 2016 and 2017 ........................... 267
5.1.2 Management applicable in 2016 and 2017 ......................... 267
5.1.3 The fishery in 2016 and expected landings in 2017 .......... 268
5.2 Commercial catch-effort data and research vessel surveys ........... 268
5.2.1 Catch-per-unit-effort ............................................................. 268
5.2.2 Survey results (Table 5.2.1, Figure 5.2.1) ............................ 268
5.2.3 Recruitment indices .............................................................. 268
5.3 Data used in the Assessment ............................................................. 268
5.3.1 Catch numbers at age (Table 5.3.1) ..................................... 268
5.3.2 Weight at age (Table 5.3.2) ................................................... 269
Constant weights at age values are used for the period 1960-1979.
For subsequent years, annual estimates of weight at age in
the catches are used. Weight at age in the stock is assumed
to be the same as weight at age in the catch. Compared to
last year, there were relatively small differences in weight at
age for the most important age groups in 2016. ................ 269
5.3.3 Natural mortality .................................................................. 269
5.3.4 Maturity at age (Table 5.3.3) ................................................ 269
5.3.5 Tuning data (Table 5.3.4, Figures 5.3.1-5.3.2) .................... 269
5.4 SAM runs and settings ....................................................................... 270
5.5 Final assessment run (Tables 5.5.1-5.5.5, Figures 5.5.1-5.5.4) ........ 270
5.5.1 SAM F, N and SSB results (Tables 5.5.3-5.5.5, Figures 5.5.3-
5.5.4) ........................................................................................ 270
5.5.2 Recruitment (Tables 5.3.1 and 5.5.6, Figure 5.1.1and
5.5.6) ........................................................................................ 270
5.6 Reference points (Figure 5.1.1) .......................................................... 271
5.6.1 Harvest control rule .............................................................. 271
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5.7 Predictions ............................................................................................ 271
5.7.1 Input data (Table 5.7.1) ......................................................... 271
5.7.2 Catch options for 2017 (short-term predictions)(Tables 5.7.2-
5.7.3) ........................................................................................ 272
5.7.3 Comparison of the present and last year’s assessment .... 272
5.8 Comments to the assessment and the forecast (Figure 5.5.4). ....... 272
6 Beaked redfish (Sebastes mentella) in Subareas 1 and 2 ...................... 294
6.1 Status of the Fisheries ........................................................................ 294
6.1.1 Development of the fishery.................................................. 294
6.1.2 Bycatch in other fisheries ..................................................... 294
6.1.3 Landings prior to 2017 (Tables 6.1—6.5, 6.12, 6.13, Figure
6.1) ........................................................................................... 294
6.1.4 Expected landings in 2017 .................................................... 295
6.2 Data used in the Assessment ............................................................ 296
6.2.1 Length- composition from the fishery (Figure 6.3) ........... 296
6.2.2 Catch-at-age (Tables 6.6 and 6.8, Figure 6.4) ..................... 296
6.2.3 Weight-at-age (Table 6.7, Figures 6.5, 6.6) ......................... 296
6.2.4 Maturity-at-age (Table 6.19, Figure 6.7) ............................. 297
6.2.5 Scientific surveys ................................................................... 297
6.3 Assessment .......................................................................................... 298
6.3.1 Results of the Assessment (Tables 6.20—6.21, Figures 6.16—
6.21) ......................................................................................... 298
6.4 Comments to the assessment ............................................................ 299
6.5 Biological reference points ................................................................ 300
6.6 Management advice ........................................................................... 300
6.7 Implementing the ICES FMSY approach ........................................... 300
6.8 Possible future model developments .............................................. 300
7 Golden redfish (Sebastes norvegicus) in Subareas 1 and 2 .................. 345
7.1 Status of the Fisheries ........................................................................ 345
7.1.1 Recent regulations of the fishery ......................................... 345
7.1.2 Landings prior to 2016 (Tables 7.1–7.4, D1 & D2, Figures 7.1-
7.2) ........................................................................................... 345
7.1.3 Expected landings in 2017 .................................................... 346
7.2 Data Used in the Assessment (Table 0.1 and Figure E2) .............. 346
7.2.1 Catch at length and age (Table 7.5) ..................................... 346
7.2.2 Catch weight at Age (Table 7.6) .......................................... 346
7.2.3 Maturity-at-age (Table E4, Figure 7.7a-b) .......................... 346
7.2.4 Survey results (Tables E1a,b-E2a,b-E3, Figures 7.4a,b–
7.5a,b) ...................................................................................... 346
7.3 Assessment with the GADGET model ............................................ 347
7.3.1 Description of the model ...................................................... 347
7.3.2 Data used for tuning ............................................................. 348
7.3.3 Assessment results using the Gadget model ..................... 349
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7.4 State of the stock ................................................................................. 350
7.4.1 Biological reference points ................................................... 351
7.4.2 Management advice .............................................................. 352
7.4.3 Implementing the ICES FMSY framework ............................ 352
8 Greenland halibut in subareas 1 and 2 (ghl.27.1-2)............................... 389
8.1 Status of the fisheries ......................................................................... 389
8.1.1 Landings prior to 2016 (Tables 8.1–8.8) .............................. 389
8.1.2 ICES advice applicable to 2016 and 2017 ........................... 389
8.1.3 Management .......................................................................... 390
8.1.4 Expected landings in 2016 .................................................... 390
8.2 Status of research ............................................................................... 390
8.2.1 Survey results (Tables F1-F5) ............................................... 390
8.2.2 Commercial catch-per-unit-effort (Table 8.6 and F5 and
Figure F5)................................................................................ 391
8.2.3 Age readings .......................................................................... 391
8.3 Data used in the assessment ............................................................. 392
8.4 Methods used in the assessment ...................................................... 393
8.4.1 Model settings ........................................................................ 393
8.5 Results of the Assessment ................................................................. 394
8.5.1 NEA Greenland halibut surplus production models ....... 395
8.6 Comments to the assessment ............................................................ 396
9 Barents Sea Capelin .................................................................................... 435
9.1 Regulation of the Barents Sea Capelin Fishery .............................. 435
9.2 TAC and Catch Statistics (Table 9.1) ............................................... 435
9.3 Sampling .............................................................................................. 435
9.4 Stock Size Estimates ........................................................................... 436
9.4.1 Acoustic stock size estimates in 2017 (Table 9.2) .............. 436
9.4.2 Recruitment estimation in 2017 (Table 9.3) ........................ 436
9.4.3 Assessment results ................................................................ 436
9.4.4 Recruitment ............................................................................ 437
9.4.5 Comments to the assessment ............................................... 437
9.4.6 Ecological considerations ..................................................... 438
9.4.7 Further work on survey and assessment methodology ... 438
9.5 Reference points ................................................................................. 439
9.6 References ........................................................................................... 439
10 Anglerfish in ICES Subareas I and II ...................................................... 451
10.1 General .................................................................................................. 451
10.2 Data ....................................................................................................... 453
10.3 Management considerations .............................................................. 455
11 References..................................................................................................... 468
Annex 1: List of participants .............................................................................. 477
ICES AFWG REPORT 2017 | vii
Annex 2: Recommendations .............................................................................. 478
Annex 3: ToRs for the next meeting ................................................................. 479
Annex 4: List of Working Documents .............................................................. 481
Annex 5: List of Stock Annexes ......................................................................... 482
Annex 6: Audit reports ........................................................................................ 483
Annex 7: Template for moving category 3 stocks to category 1: cod.27.1-2
coast ............................................................................................................... 493
2 | ICES AFWG REPORT 2017

Executive summary
The Arctic Fisheries Working Group (AFWG), chaired by Daniel Howell, Norway, met at ICES
Headquarters, Copenhagen, Denmark, 19–25 April 2017.
Cod in subareas 1 and 2 (Norwegian coastal waters)
The cod in subareas 1 and 2, Norwegian coastal waters was assessed on the basis of a survey time
series 1995–2016 as well as catch at age data (including recreational and tourist fisheries). This is a
category three stock.
 The stock has varied without a clear trend since 2002. Both the stock biomass and the
recruitment are at a low level compared to the first years in the time series. Fishing pres-
sure (F) increased in 2015 and 2016, after a declining trend over the period 2000-2014. A
rebuilding plan for this stock was introduced in 2011.
Cod in subareas 1 and 2 (Northeast Arctic) was for the first time assessed using the SAM model
following the outcome of the interbenchmark meeting (IBP cod 2017). The IBP also recommended
extending the catch data to age 15+, and to evaluate the survey data on an annual basis to select
appropriate age-ranges. The IBP recommended that the current model of natural mortality (M=0.2
plus modelled cannibalism) and methods for evaluating maturity at age should be retained.
 The change in assessment model as well as inclusion of a wider age range and data from the
last year changed the stock composition considerably compared to last year’s assessment.
The abundance of age 9 and older fish in 2016 was increased compared to last year, while
the abundance of younger age groups was decreased. Overall, this led to minor revisions of
current total stock biomass, but the predictions indicate lower stock size and catches than in
last year’s assessment. The estimated F5-10 in 2016 is below Fpa, and SSB well above Bpa, alt-
hough somewhat lower than the peak in 2013.
 Following the evaluation of harvest control rules in 2016, the Joint Norwegian-Russian Fish-
eries Commission in October 2016 adopted a new harvest control rule for this stock. In the
new rule, fishing mortality is increased at high SSB values, and the constraint on annual
variation in TAC when SSB is now 20% (previously 10%).
 The TAC advice for 2018 is 712 000 tonnes, corresponding to F=0.44. The advice is con-
strained by the limit of 20% annual TAC decrease from year to year.
Haddock in subareas 1 and 2 (Northeast Arctic) was assessed using SAM, following the recom-
mendations from WKARCT in 2015.
 Three subsequent cohorts (2004–2006) were all very abundant and the 2005–2006 cohorts
still make up a considerable proportion of the total haddock biomass.
 The fishing mortality (F4–7) has been around 0.20 since 2009. Note that a large proportion of
the catches in recent years has been from age groups outside the reference age range. The
total stock peaked in 2009 while SSB reached an all-time high in 2012-2015. SSB is now de-
creasing but still at a high level.
 The evaluated and agreed HCR gives a catch in 2018 of no more than 202 000 tonnes, corre-
sponding to a 13% decrease from the TAC in 2017. This corresponds to a fishing mortality
of 0.35. A decrease in stock size and catch level towards a more normal situation is expected
in the coming years. However, the 2016 year class is very abundant at age 1 in surveys.