ICES advice on fishing opportunities in 2019 Herring stocks. Eskild Kirkegaard, ICES ACOM Chair Pelagic AC, 5th July 2018

Transcription

1 ICES advice on fishing opportunities in 2019 Herring stocks Eskild Kirkegaard, ICES ACOM Chair Pelagic AC, 5th July 2018

2 Rules for advice on fishing opportunities The advice rules applied by ICES in developing advice on fishing opportunities depends on: - management strategies agreed by relevant management bodies and - the information and knowledge available for the stock

3 EU Multi Annual Plans (MPAs) Advice on: status of stock and exploitation for all stocks advice and advice on fishing opportunities for stocks for which TACs are set. EU Multi Annual Plans (MPAs)

4 Type of advice depends on whether a stock is considered a target stock in the MAP or not, and whether F ranges are defined for the stock. a) Target stocks with F ranges and not shared with third party. Advice to be based on F range. b) Target stocks with no range defined or shared with third party. Advice to be based agreed management plan, ICES MSY or ICES PA. c) Non-target stocks with TAC and shared with third party. Advice to be based on agreed management plans, ICES MSY or ICES PA. d) Non-target stocks with TAC and not shared with third party. Advice to be based on ICES PA. e) Non-target stocks with no TAC. No advice on fishing opportunities. EU Multi Annual Plans (MPAs)

5 Basis for advice Stocks HERRING: North Sea Western Baltic, Skagerrak, Kattegat Celtic Sea Irish Sea 6a and 7b,c Basis for catch advice ICES MSY ICES MSY ICES MSY ICES MSY ICES MSY Comments Range not defined. Shared EU - Norway Range defined. Shared EU Norway Range not defined Range not defined Range not defined

6 ICES MSY approach more caution below B lim Maximize long term average yield Safeguard against low SSB Stay within precautionary boundaries F MSY B trigger F MSY B lim Category 1 and 2 stocks SSB at start of advisory year

7 Herring in Subdivisions (Western Baltic Spring Spawning Herring)

8 Western Baltic spring spawning herring (subdivisions 20-24) ICES advises that when the MSY approach is applied, there should be zero catch in Figure 1 Herring in subdivisions 20 24, spring spawners. Commercial catches, recruitment, fishing mortality, and spawning SSB below B lim F above F MSY Recruitment has been low since the mid-2000s Recruitment 2016 & 2017 lowest in the time series Catch (2017) = ( ~ 99.6% directed fishery; discarding negligible) Mixing with North Sea herring in Division 3a and eastern part of Subarea 4

9 Western Baltic spring spawning herring (subdivisions 20-24) Catch prediction - assumptions Variable Value Notes F ages 3 6 (2018) 0.30 Catch constraint SSB (2018) Catch constraint R age 0 (2018) Geometric mean R age 0 (2019) Geometric mean Total catch (2018) Agreed EU Norway catch options (EU Norway, 2016), including an assumed 46% transfer ( t) of the C-fleet TAC to the North Sea (in tonnes). Utilization of the TAC in 2018 of 100% for the F-fleet, 54% for the C-fleet, 46% for the D-fleet, and a small catch of western Baltic spring-spawning herring in the A-fleet (based on the average of , see table 8 for definition of fleets). Ratios between the North Sea and western Baltic herring stocks in Division 3.a and Subarea 4 are based on the average proportions in the catches.

10 Basis Total catch (2019) F 3-6 (2019) SSB* (2019) SSB* (2020) % SSB change ** % advice change *** ICES advice basis MSY approach: zero catch % -100% Other scenarios MAP (2018)^: F = F MSY SSB 2018 /MSY B trigger % -22% MAP (2018)^: F = F MSY lower (SSB 2018 /MSY B trigger ) % -44% MAP (2018)^: F = F MSY upper (SSB 2018 /MSY B trigger ) % -7.1% F MSY % 7.2% F = F pa % 19.0% F = F lim % 46% SSB (2020) = B lim ^^ % -100% SSB (2020) = B pa^^ % -100% SSB (2020) = MSY B trigger^^ % -100% F = F % 3.6% MAP (2016)^^^: F = F MSY SSB y-1 / MSY MAP B trigger % 5.1% MAP (2016)^^^: F = F MSY.lower SSB y-1 / MSY MAP B trigger % -21% MAP (2016)^^^: F = F MSY.upper SSB y-1 / MSY MAP B trigger % 30% F = 0 {SSB 2021 = } ^^^^ % -100% F = 0.05 {SSB 2021 = } ^^^^ % -81% F = 0.1 {SSB 2021 = } ^^^^ % -63% F = 0.15 {SSB 2021 = } ^^^^ % -46%

11 This stock was benchmarked in The new assessment shows a better retrospective pattern. The historic perception of SSB and recruitment have been revised downwards in this process assessment 2018 assessment

12 Western Baltic spring spawning herring (subdivisions 20-24) Revised Reference Points Reference point Old Value New Value MSY B trigger F MSY B lim B pa F lim F pa

13 North Sea Herring (3a, 4 and 7d) Autumn spawners

14 North Sea Herring (3a, 4 and 7d) Catches by statistical rectangle in 2017

15 North Sea Herring (3a, 4 and 7d) ICES advises that when the MSY approach is applied, catches in 2019 should be no more than tonnes, which includes tonnes for the A-fleet. Fishing mortality below F MSY since Recruitment has been relatively low since 2002, with the two lowest year classes falling within the recent four of the last 30 years. Spawning biomass above MSY B trigger since Catch in 2017 = t. (99% directed fishery, 1% bycatch

16 North Sea Herring (3a, 4 and 7d) North Sea herring fisheries Area where NSAS are caught Fleet Fishery NSAS 2017 catches (tonnes) North Sea fisheries (Subarea 4, Division 7.d) A Directed herring fisheries B Bycatches of herring 6976 Division 3.a C Directed herring fisheries 7404 D Bycatches of herring 196

17 North Sea Herring (3a, 4 and 7d) Catch forecast The 2017 assessment predicted a reduction in stock size in 2018 and 2019 due to the weak 2014 year class. Confirmed by the 2018 assessment. The intermediate year (2018) assumptions: Variable Value Notes F ages (wr) 2 6 (2018) 0.38 Catch constraint. SSB (2018) Calculated based on catch constraint (in tonnes). R age (wr) 0 (2018) Estimated by assessment model (in thousands). R age (wr) 0 (2019) Weighted mean over (in thousands). Total catch (2018) Agreed catch options, including a 46% transfer ( t) of C-fleet TAC to the A-fleet in the North Sea (in tonnes). F by fleet and total Catches by fleet F ages F ages F ages F ages SSB F ages F ages Catches Catches CatchesCfleefleet CatchesD- (wr) 2 6 (wr) 0 1 (wr) 0 1 (wr) (wr) 2 6 (wr) 0 1 A-fleet B-fleet A-fleet B-fleet C-fleet D-fleet

18 North Sea Herring (3a, 4 and 7d) Catch forecast A management strategy has not been agreed for 2019, and the advice is based on the ICES MSY approach. F for ages 0 1 is maintained to the 0.05 target. The C-fleet and D-fleet catches to zero, consistent with the zero catch advised for WBSS. ICES currently has no method for fleet-based MSY advice and other catch distribution scenarios could be provided on request from clients.

19 A-fleet **** %TAC change Basis A-fleet F ages (wr) B-fleet F ages (wr) North Sea Herring (3a, 4 and 7d) F values by fleet and total C-fleet F ages (wr) D-fleet F ages (wr) F ages (wr) F ages (wr) Catches by fleet Biomass* % A-fleet B-fleet C-fleet # D-fleet # Total stock catch SSB 2019 %SSB SSB 2020 ** change *** MSY approach^^ Other scenarios EU Norway Management strategy F = F MSY F = No change in A- fleet TAC A-fleet TAC reduction of 15% A-fleet TAC increase of 15% F = F F pa F lim SSB 2019 = B pa SSB 2019 = B lim * For autumn-spawning stocks, the SSB is determined at spawning time and is influenced by fisheries between 1 January and spawning. ** Assuming same catch option in 2020 as in *** SSB (2019) relative to SSB (2018). **** A-fleet catches (2019) relative to TAC 2018 for the A-fleet ( tonnes). ^ Advice value 2019 relative to advice value 2018, using catches for all fleets. ^^ Following the MSY advise rule FMSY SSB2019/MSY Btrigger (ICES, 2016). ^^^ MSY Btrigger cannot be reached in # The catch for C and D fleets are set to zero because of the zero catch advice given for 2019 for the Western Baltic spring-spawning herring stock. Advice change ^

20 North Sea Herring (3a, 4 and 7d) 2018 assessment 2017 assessment Benchmarked in Natural mortality updated - multispecies assessment model. Assessment methodology updated. More precise stock estimates and reduced assessment bias. New natural mortality resulted in a rescaling of SSB and F. The reference points were updated accordingly.

21 Natural mortality North Sea Herring (3a, 4 and 7d)

22 North Sea Herring (3a, 4 and 7d) Reference points Framework Reference point 2018 assessment 2017 assessment MSY B trigger t MSY approach F MSY B lim t Precautionary approach B pa t F lim F pa

23 North Sea Herring (3a, 4 and 7d) EU Norway request for advice on management strategy For North Sea autumn-spawning herring ICES is asked to: 1. Tabulate the long-term yield, long term SSB, inter annual TAC variability and risk of SSB falling below Blim for the range of combinations of Btrigger and Ftarget values evaluated. 2. Estimate the combination of Ftarget and Btrigger that maximises yield given the rules set out in five sets defined in the table attached. The five sets are A, B, A+C, A+D and B+D. 3. Evaluate the performance of the four sets of rules with corresponding pairs of Ftarget and Btrigger and the additional fishing pressure scenarios of 0.9*Ftarget, Ftarget, 1.1*Ftarget, FMSY lower and FMSY upper. (5 pairs, 5 sets = 25 scenarios).

24 Herring in 7.a South of N and 7.gh,jk (Irish Sea, Celtic Sea and Southwest of Ireland)

25 Herring in 7.a South of N and 7.gh,jk (Irish Sea, Celtic Sea and Southwest of Ireland) ICES advises that when the MSY approach is applied, catches in 2019 should be no more than tonnes. SSB has been decreasing significantly since its peak in 2011, and is now below MSY B trigger at Blim. F has increased since 2008 and has been above F MSY since Recruitment has been below average since Catch in 2017 = t. (100% pelagic trawl)

26 Herring in 7.a South of N and 7.gh,jk (Irish Sea, Celtic Sea and Southwest of Ireland) Catch scenarios assume catch in 2018 = t Recruitment 2018/2019 = Based on stock-recruitment relationship SSB(2018) = t < MSY B trigger ( t) F MSY = 0.26 Basis Total catch (2019) F 2 5 (2019) SSB (2019) * % SSB change ** SSB (2020) * % TAC change *** % Advice change ^ ICES advice basis MSY approach: F MSY SSB 2018 /MSY B trigger Other scenarios F MSY F = F pa F lim SSB (2019) = B lim SSB (2019) = B pa ^^ SSB (2019) = MSY B trigger ^^ F = F

27 Inter-benchmarked in The survey estimates were revised, the range of age classes in the survey was reduced, and assumptions regarding selectivity at older ages were revised. These changes improved diagnostics and reduced retrospective patterns, although there was little change in the perception of current stock status

28 Mean weight (kg) Celtic Sea herring 0,35 0,3 0,25 0,2 0,15 0,1 0,05 Mean Weights in the Catch Year

29 Herring in Division 7.a North of 52º 30 (Irish Sea)

30 Herring in Division 7.a North of 52º 30 (Irish Sea) ICES advises that when the MSY approach is applied, catches in 2019 should be no more than 6896 tonnes. SSB has been above MSY B trigger since F has decreased since 2003 and has been below F MSY since There has been stronger recruitment since Recruitment in 2017 is low. Catch in 2017 = t. (100% pelagic trawl)

31 Herring in Division 7.a North of 52º 30 (Irish Sea) Assume that catch for 2018 = TAC constraint = t Recruitment 2017/2018 = geometric mean. SSB(2018) = t > MSY B trigger ( t) F MSY = Basis Total catch (2019) F total (2019) SSB * (2019) % SSB change ** SSB (2020) *^ % TAC change *** % Advice change ^^ ICES advice basis MSY approach: F MSY Other scenarios F = F pa F lim SSB (2019) = B lim SSB (2019) = B pa SSB (2019) = MSY B trigger

32 Herring in Division 7.a North of 52º 30 (Irish Sea) Benchmarked in 2017 New acoustic survey included in assessment. Revised perception -significant upwards revisions of the SSB and recruitment -downward revision of fishing mortality assessment consistent with 2017.

33 Herring in Divisions 6.a and 7.b,c (West of Scotland, West of Ireland)

34 Herring in Divisions 6.a and 7.b,c (West of Scotland, West of Ireland) ICES advises that when the ICES MSY approach is applied, there should be zero catch in ICES recommends that a stock recovery plan is implemented for these combined stocks. Represents two stocks (divisions 6.a(N) and 6.a(S), and divisions 7.b c) assessed as one. SSB has been declining since 2004 and is estimated to have been below B lim since F has been below F MSY since the late 1990s. Recruitment has been at unprecedented low levels since Catch in 2017 = t.

35 Herring in Divisions 6.a and 7.b,c (West of Scotland, West of Ireland) Catch options ICES in 2016 provided advice on a scientific monitoring fishery = 4840 t Assume agreed scientific monitoring TAC of 5800t B lim = t Basis Total catch (2019) F total (2019) SSB * (2019) SSB ** (2020) % SSB change *** % TAC change ^ ICES advice basis MSY approach: zero catch Other scenarios 2018 Monitoring TAC Advice for scientific monitoring (ICES, 2016 ) Proposed rebuilding plan: lower of F 2019 = SSB 2018 /MSY B trigger *F MSY or F 2019 = F catch : 5800 tonnes F MSY F pa F lim SSB (2020) = B lim^ SSB (2020) = B pa = MSY B trigger^^^ F 2019 = F % Advice change ^^

36 Herring in Divisions 6.a and 7.b,c (West of Scotland, West of Ireland) The 2017 and the 2018 assessment have resulted in a historical downward revision of the stock size. Uncertainties affecting the quality are a lack of information on recruitment and the abundance of fish of younger ages, sensitivity to assumptions of future recruitment and age-dependent catchabilities, and the model s apparent overestimation of the abundance of older fish in the stock relative to that observed in the Malin shelf acoustic survey and catches since 2013.

37 Herring in Divisions 6.a and 7.b,c (West of Scotland, West of Ireland) A rebuilding plan, which contains provisions for a monitoring TAC whilst the combined stocks remain below Blim, was evaluated by ICES in 2017, and found not to be precautionary. A key aim of the plan is to provide for sampling opportunities for continuation of the assessment input catch-at-age information and sample collection for stock discrimination research, whilst ensuring that the stock can be rebuilt. A revised version of the rebuilding plan was submitted to the European Commission in 2018 but has not been evaluated by ICES.

38 Heering - recruitment 3 2,5 2 1,5 1 0,5 0 Herring, relative recruitment Celtic Sea, Irish Sea, 6a, 7b,c, North Sea and Western Baltic 3 2,5 2 1,5 1 0,5 0 Herring, reletive recruitment Celtic Sea, 6a, 7b,c, North Sea and Western Baltic North Sea 6a 7b,c Celtic Sea Irish Sea Western Baltic North Sea 6a 7b,c Celtic Sea Western Baltic

39 Thank you