ICES advice for 2017: widely distributed pelagic stocks Carmen - - PowerPoint PPT Presentation

ICES advice for 2017: widely distributed pelagic stocks

Carmen Fernández, ICES ACOM vice-chair For PelAC (The Hague, October 5, 2016)

Basis for ICES Advice

Management Plan / Strategy

Consistent with Precautionary Approach & agreed by competent authorities as potential basis for advice

ICES MSY approach

No No

ICES PA approach

Basis of ICES Advice

Basis of ICES Advice

Stock categories (based on available knowledge) Advice basis

1 Stocks with an accepted analytical assessment and forecast MSY approach 2 Stocks with an analytical assessment and forecast accepted for trends only MSY approach 3 Stocks with abundance or biomass indices indicative trends Precautionary approach MSY approach being developed 4 Stocks with reliable catch and biological data Precautionary approach MSY approach being developed 5 Only landings available Precautionary approach 6 Only landings available and largely discarded Precautionary approach

 Maximize long term average yield  Safeguard against low SSB  Stay within precautionary boundaries (WKMSYREF 2, 3 & 4, 2014-15)

MSY Btrigger FMSY SSB at start of advisory year

more caution below Blim

F

ICES MSY approach (Category 1 stocks)

ICES MSY Advice Rule (AR):

ICES MSY approach for Category 1 stocks

 Implemented since 2012  Various approaches depending on available information  Advice Rules providing quantitative advice are available for all stock categories

Advice framework for stocks in categories 3-6

ICES MSY approach

Advice based on previous advice [or recent catch or landings], modified according to index information; typically last 5-year index trend: Advice = previous advice x

average of index in last 2 years average of index in 3 previous years

also incorporating:

• 1. Uncertainty cap (20% change limit, to dampen noise)
• 2. Precautionary buffer (20% reduction if status in relation to reference points

unknown --- exceptions if significant increases in stock size or reductions in exploitation)

• Advice normally does not change every year

Category 3 (stocks with abundance index)

ICES MSY approach for Category 1 stocks

 Now in the process of developing MSY proxy reference points for stocks in categories 3 & 4  Done for stocks in Western Waters (EU special request, 2016)  Work for stocks in other regions to follow shortly

Advice framework for stocks in categories 3-6

ICES MSY approach

• ICES advice:
• A. if discards can be quantified

 catch advice

• B. if discards unknown (possibly qualitative information)

 catch advice if information indicates discard rate < 5% (discards negligible in the context of precision of advice)  landings advice if information very uncertain or discard rate considered to be > 5%

Catch advice

ICES MSY approach

For stocks starting EU landing obligation: To provide clear linkage to previous advice on catch and landings the advised catches are split into two components, termed wanted catch and unwanted catch.

• “Wanted catch” is used to describe fish that would be landed in the absence of the EU

landing obligation

• “Unwanted catch” refers to the component that was previously discarded.

This split, based on the past performance of the fishery, is expected to evolve and the relative magnitude of the components will change, e.g. after some years of LO data, we may have: landings wanted, landings unwanted, discards

Terminology: Wanted & Unwanted catch

New structure of advice:

For each ecoregion:

• Stock advice (new format implemented last year: shorter and

more directly focussed on the catch advice)

• Fisheries advice / overviews (being developed)
• Ecosystem advice / overviews (being developed)

Advice format

All advice available online at: http://www.ices.dk Click on Follow Advisory process  Latest advice In addition to advice items, “Introduction to ICES Advice” document describes principles and advice basis For advice release dates, follow link: Follow Advisory process  Advice requests and advice release dates Email contact (e.g. to enquire about workshops, registration to workshops...): advice@ices.dk

Widely distributed stocks

Advice for 2017, MSY approach: Catch ≤ 1 342 330 t

* SSB increasing since 2011, above MSY Btrigger * F above FMSY * Recent recruitment above average Inter-Benchmark in 2016:

• Some changes to model settings
• Now includes preliminary catch

data from assessment year (2016)

• Assessment results consistent

with last year’s

• Reference points re-evaluated,

resulting in changes to: Flim (0.88), Fpa (0.53), FMSY (0.32) NEAFC request to evaluate HCR

Blue whiting in Subareas 1-9, 12, 14

Fishing pressure Stock size 2014 2015 2016 2015 2016 2017 Maximum sustainable yield FMSY Above MSY Btrigger Above trigger Precautionary approach Fpa, Flim Harvested sustainably Bpa, Blim Full reproductive capacity Management plan FMGT

• Not applicable

SSBMGT

• Not applicable

Blue whiting in Subareas 1-9, 12, 14

Catch 2015: 1.396 million t

• Discard ratio is < 0.5 %
• Landings: 98% pelagic trawl, 2% bottom trawl

From WGWIDE report: Main fisheries target spawning and post-spawning fish. ~ 90% of catch taken in first two quarters of the year The bulk of the catch is caught with large pelagic trawlers, some with capacity to process or freeze on

• board. The remainder is caught by RSW vessels.

Blue whiting in Subareas 1-9, 12, 14

Assumptions 2016: Catch = 1.147 million t (based on declared quotas and expected uptake)

 SSB(2017)= 6.80 million t > MSY Btrigger (2.25 million t) * Catch(2017) relative to estimated catch in 2016 (1.147 million t)

Big increase in catch advice for 2017 compared to last year’s advice for 2016, mainly due to:

• Recruitment (age 1) in 2014 and 2015 now estimated to be much larger than assumed last year
• Upwards revision in FMSY (from 0.30 to 0.32)

Rationale Catch (2017) Basis F 2017 SSB (2018) % SSB change 2018 vs 2017 % Catch change * MSY approach 1342330 FMSY = 0.32 0.32 6700746 −2 17 Other options F = 0 7984004 17 −100 793663 F = 0.18 0.18 7225455 6 −31 875482 F = 0.20 0.20 7147053 5 −24 956118 F = 0.22 0.22 7069836 4 −17 1074904 F = 0.25 0.25 6956183 2 −6 1152681 (~1147 kt) Catch 2017 = Catch 2016 0.27 6881829 1 1582620 F (2016) 0.39 6471736 −5 38 2070268 Fpa 0.53 6008626

• 12

80 3077862 Flim 0.88 5059556 −26 168 6159997 SSB2018 = Bpa 2.88 2257026 −67 437 7039918 SSB2018 = Blim 4.16 1507999 −78 514

Blue whiting: NEAFC request to evaluate LTMS

Harvest Control Rule: Btrigger = Bpa (2.25 million t); Blim = 1.5 million t; FMSY = 0.32 If SSB(Jan 1 TAC yr) ≥ Btrigger  20% interannual TAC limit 10% interannual quota flexibility (suspended if SSB forecast to be < Btrigger at end of TAC yr) Advice:

• HCR is precautionary
• HCR precautionary both with and without the 20% TAC change limits above Bpa
• 20% TAC change limits can lead to the TAC being lowered significantly if the stock is estimated to be below Bpa, while

limiting how quickly the TAC can increase once the stock is estimated to have recovered above Bpa

• Including a 10% interannual quota flexibility had an insignificant effect on the performance of the HCR.

Lower target F (F applied above Btrigger) would lead to less interannual variability in TAC (higher SSB and more robust to assessment uncertainty)

HCR evaluated via stochastic long-term simulation, including variability (and autocorrelation) in recruitment and uncertainty in assessment and advice

SSB(Jan 1 TAC yr)

Advice for 2017, EU, Faroes, Iceland, Norway MP: Catch ≤ 646 075 t

Norwegian spring-spawning herring (Subareas 1, 2, 5, & Divisions 4a, 14a)

Fishing pressure Stock size 2013 2014 2015 2014 2015 2016 Maximum sustainable yield FMSY Appropriate MSY Btrigger At trigger Precautionary approach Fpa Harvested sustainably Bpa, Blim Full reproductive capacity Management plan FMGT Appropriate SSBMGT At trigger

* SSB declining, now close to MSY Btrigger * F below FMSY * Last large recruitment (age 2) was 2006 Benchmark in 2016:

• New assessment model that takes better

account of error structure in observations Declining trend in SSB less pronounced and estimates of SSB in recent years higher than in last year’s assessment. Estimates from exploratory runs with other models were within confidence intervals of current assessment In autumn 2016: Re-evaluation of reference points and LTMP

Catch 2015: 329 kt

• Discarding negligible
• Landings: ~51% purse seine, ~49% pelagic

trawl From WGWIDE report: 2015 fishery had similar pattern to recent years Q1: Fishery began in January on Norwegian shelf (overwintering, pre-spawning, spawning and post-spawning fish) Q2: fishery insignificant Q3: Faroese and Icelandic waters and north to Jan Mayen and Svalbard Q4: Central part of Norwegian Sea and

• verwintering area in fjords and oceanic areas

north of Tromsø 58% of catches taken in Q4

Norwegian spring-spawning herring (Subareas 1, 2, 5, & Divisions 4a, 14a)

Assumptions 2016: Catch = 377 kt (based on declared quotas)

 SSB(2017)= 4.974 million t < MSY Btrigger (5 million t) ^ F linear decrease from 0.125 when SSB(TAC yr)=Bpa to 0.05 when SSB(TAC yr)=Blim. * Catch(2017) relative to estimated catch in 2016 (377 kt)

Big increase in catch advice for 2017 compared to last year’s advice for 2016, mainly because

• F in MP HCR is reduced when SSB(TAC year) is < Bpa:

In last year’s assessment: SSB(2016) estimated to be 28% below Bpa  F to be applied: 0.083 In this year´s assessment: SSB(2017) estimated to be 1% below Bpa  F to be applied: 0.124

Rationale Catches (2017) Basis Fw(2017) SSB(2018) % SSB change 2018 vs 2017 % Catch change Agreed management plan 646075 Harvest control rule^ 0.124 4898000 −2 72 Other options 766676 ICES MSY approach: FMSY* SSB(2017) / MSY Btrigger 0.149 4794000 −4 104 F = 0 5459000 10 −100 339833 F2016 0.063 5163000 4 −10 770384 FMSY (= Fpa) 0.150 4791000 −4 105 528271 SSB2018 = Bpa (= MSY Btrigger) 0.100 5000000 1 40 3493537 SSB2018 = Blim 0.978 2500000 −50 828

Norwegian spring-spawning herring (Subareas 1, 2, 5, & Divisions 4a, 14a)

Horse mackerel (Trachurus trachurus)

• North Sea stock: 3a, 4bc, 7d
• Western stock: 2a, 4a, 5b, 6a, 7 (exc. 7d), 8

Catch in Divisions 3a and 4a: Q1 & Q2: allocated to North Sea stock Q3 & Q4: allocated to Western stock

• Southern stock: 9a

Advice for 2017, Precautionary approach: Catch ≤ 18 247 t

North Sea horse mackerel

Fishing pressure Stock size 2013 2014 2015 2013 2014 2015 Maximum sustainable yield FMSY Undefined MSY Btrigger Undefined Precautionary approach Fpa, Flim Undefined Bpa, Blim Undefined Management plan FMGT

• Not applicable

SSBMGT

• Not applicable

Qualitative evaluation

• Unknown
• Increasing

Q4 in 7d, < 20 cm

* Category 5 stock: Indices provide overall perspective, but are very uncertain and individual years are not considered indicative of trends (also CGFS changed vessel in 2015 – calibration study is being reviewed by ICES) * The CGFS survey (Q4 in 7d) indicates an increase in recent years * Increase much less clear in IBTS survey (Q3 in 4bc) * Overall, the stock appears to remain at a low level Benchmark in 2017

Q4 in 7d, ≥ 20 cm Q3 in 4bc, < 20 cm Q3 in 4bc, ≥ 20 cm

complete discard estimates

• nly in some years
• Discarding in target pelagic fisheries

considered negligible

• New information from bottom trawl fisheries not

directed to horse mackerel indicates discarding in 2015 (16.7% of total stock catches). Discarding in earlier years to be examined in 2017 benchmark.

North Sea horse mackerel

Recent advised catch for 2016 15 200 t Discard rate** 16.7% Precautionary buffer Not applied

• Catch advice for 2017*

18 247 t Wanted catch corresponding to the catch advice 15 200 t

• Advice as last year but taking into account the new information on discarding

* (Recent advised catch) / (1 – discard rate) ** The majority of discards come from non-directed, demersal fisheries Fisheries focussed on smaller fish in 2015, and this is expected to continue in 2016 and 2017. This exploitation pattern, catching mostly immature individuals, might hinder stock recovery.

Precautionary buffer not applied (20% reductions relative to recent catch were applied in the advice for 2013 and 2015)

• Catch (2015) = 12 002 t (16.7% discarded, non-directed fisheries)

Corrected catch advice for 2016, MSY approach: Catch ≤ 773 842 t

The IBTS Recruitment index was used incorrectly in the 2015 mackerel assessment. Corrected catch advice for 2016, based on the corrected 2015 assessment, was issued by ICES in September 2016. The correction results in a 14% upwards revision of the SSB value in 2015 and a 3% downwards revision of the F value in 2014 relative to the advice released in September 2015. Applying the MSY approach results in a 16% upwards revision of the catch advice for 2016.

Mackerel in Northeast Atlantic

Advice for 2017, MSY approach: Catch ≤ 944 302 t Measures to protect North Sea spawning component should remain in place

* SSB increased since early 2000s, above MSY Btrigger since 2009 * F above FMSY * Several large year classes since 2002 Triennial egg survey: conducted in 2016, index lower than in 2013 IESSNS survey indices in 2016 higher than in 2015 SSB estimates from this year’s assessment closer to those from the 2014 than from the (corrected) 2015 assessment In 2017: Benchmark and evaluation of LTMS

Mackerel in Northeast Atlantic

Fishing pressure Stock size 2013 2014 2015 2014 2015 2016 Maximum sustainable yield FMSY Above MSY Btrigger Above trigger Precautionary approach Fpa, Flim Increased risk Bpa, Blim Full reproductive capacity Management plan FMGT

• Not applicable

SSBMGT

• Not applicable

Mackerel in Northeast Atlantic

Catch 2015: 1.209 million t

• Discard ratio is < 1 %
• Landings: ~79% pelagic trawl,

~21% purse seine From WGWIDE report: Geographical expansion of the northern summer fishery in recent years. Since 2010, about half of the catch taken in Q3 Quarter 1 Quarter 2 Quarter 3 Quarter 4

Mackerel in Northeast Atlantic

Assumptions 2016: Catch = 1.068 million t (based on declared quotas, interannual transfers, discards)

 SSB(2016, spawning time)= 4.96 million t > MSY Btrigger (3 million t) * Catch(2017) relative to estimated catch in 2016 (1.068 million t)

Rationale Catch (2017) F (2017 & 2018) Basis SSB (2017) Spawning time SSB (2018) Spawning time SSB change 2018 vs 2017 Catch change* MSY approach 944302 0.22 FMSY 4793232 4544588 −5% −12% Other options 0.00 F = 0 4949577 5454304 10% −100% 1020996 0.24 F in the EU, Faroe Islands, and Norway long-term management strategy 4779365 4472848 −6% −4% 1020996 0.24 F(2016) 4779365 4472848 −6% −4% 854262 0.20 Catch(2017) = 2016 catch −20% 4809265 4629238 −4% −20% 1067828 0.25 Catch(2017) = 2016 catch 4770799 4429206 −7% 0% 1281394 0.31 Catch(2017) = 2016 catch +20% 4730754 4231803 −11% 20% 982824 0.23 0.23 4786291 4508512 −6% −8% 1096301 0.26 0.26 4765554 4402734 −8% 3% 1133442 0.27 0.27 4758670 4368274 −8% 6% 1170247 0.28 0.28 4751800 4334205 −9% 10% 1058820 0.25 Fpa 4772452 4437590 −7% −1% 1453004 0.36 Flim 4697340 4075136 −13% 36% 2697591 0.80 F(2017–2018) leading to Bpa in 2018 4413138 3000000 −32% 153% 4200426 1.70 F(2017–2018) leading to Blim in 2018 3904536 1840000 −53% 293%

Horse mackerel (Trachurus trachurus)

• North Sea stock: 3a, 4bc, 7d
• Western stock: 2a, 4a, 5b, 6a, 7 (exc. 7d), 8

Catch in Divisions 3a and 4a: Q1 & Q2: allocated to North Sea stock Q3 & Q4: allocated to Western stock

• Southern stock: 9a

Advice for 2017, MSY approach: Catch ≤ 69 186 t

Western horse mackerel

* Dependent on occasional high recruitment * Recruitment since 2002 low * SSB currently at lowest observed * F has increased after 2007, around FMSY Catch(2015) = 98 419 t (~ 4% discarded)

• Large uncertainty: only-fishery independent

information is from triennial egg survey

• Egg survey in 2016 led to downward

revision of SSB estimates since early 2000s

• With SSB at lowest in time series and

limited recruitment information: difficult to predict stock development Benchmark in 2017

Fishing pressure Stock size 2013 2014 2015 2014 2015 2016 Maximum sustainable yield FMSY Appropriate MSY Btrigger Below trigger Precautionary approach Fpa, Flim Below possible candidate reference points Bpa, Blim Undefined Management plan FMGT

• Not applicable

SSBMGT

• Not applicable

Western horse mackerel

Assumptions 2016: Catch = 124 403 (EU TAC)

 SSB(2016, spawning time)= 489 616 t < MSY Btrigger (634 577 t) * Catch(2017) relative to the ICES advised catch for 2016 (126 103 t) ^ Even with 0 catch it is not possible to reach MSY Btrigger in 2018.

Big decrease in catch advice for 2017 compared to last year’s advice for 2016, mainly because

• SSB in 2017 estimated to be considerably lower than SSB in 2016 was estimated last year (almost 30% lower)
• Under ICES MSY approach F is reduced when SSB(TAC year) is < MSY Btrigger  implies F(2017) < FMSY

Rationale Catch 2017 Basis F (2017 and 2018) SSB 2017, spawn SSB 2018, spawn %SSB change 2018 vs 2017 % TAC change* MSY approach 69186 FMSY × SSB2017/MSY Btrigger 0.092 455086 490225 8 −45 96494 FMSY 0.13 445576 461276 4 −23 Zero catch F = 0 478383 566841 18 −100 Other options 93031 F2015 0.126 446793 464906 4 −26 116886 F2016 0.161 438350 440145 −7 SSB2018 = MSY Btrigger ^ 126103 ICES catch advice for 2016 0.175 435049 430740 −1

Advice for 2017, MSY approach: Catch ≤ 73 349 t. All catch assumed to be landed.

Southern horse mackerel

* F below FMSY and SSB above MSY Btrigger

• ver whole time series

* Strong recruitment in 2011 and 2012 Catch(2015) = 32 723 t (~ 51% purse-seine, 40% trawl, 9% other gears; discarding negligible)

• Reference points calculated this year

(FMSY remains at previous value) Benchmark in 2017

Fishing pressure Stock size 2013 2014 2015 2014 2015 2016 Maximum sustainable yield FMSY Below MSY Btrigger Above trigger Precautionary approach Fpa, Flim Harvested sustainably Bpa, Blim Full reproductive capacity Management plan FMGT

• Not applicable

SSBMGT

• Not applicable

Southern horse mackerel

Assumptions 2016: F(2016) = F(2015)  SSB(2016, spawning time)= 621 563 t > MSY Btrigger (181 000 t)

* Catch(2017) relative to the ICES estimated catch in 2015 (32 723 t)

Advice is for T. trachurus, while TAC is for all Trachurus species. Percentage of other Trachurus species in the horse mackerel catch varies by year. Preliminary estimates indicate this percentage was < 10% in 2012-2014. F is well below FMSY. Applying the MSY approach, F can be increased by a factor of 2.5 and catches in 2017 could be up to 73 349 tonnes. Sporadic events of strong recruitment have been observed in this stock (1996 and 2011/2012), which can result in rapid periodic increases in SSB. Not increasing F to FMSY immediately could allow spreading the yield from the two recent large year classes over a longer time period. Stochastic long-term simulations estimated an equilibrium catch at FMSY of 44 000 t.

Rationale Catches T. trachurus (2017) Basis F (2017) SSB (2017) spawn time SSB (2018) spawn time %SSB change 2018 vs 2017 % Catch change*** MSY approach 73349 FMSY 0.11 640862 605274

• 6

124 Zero catch F2017 = 0 646156 678351 5

• 100

Other options 30237 F2016 0.044 644033 648084 1

• 8

36139 F2016 × 1.2 0.053 643609 642199 10 47798 F2016 × 1.6 0.070 642763 630596

• 2

46 59269 F2016 × 2.0 0.088 641917 619209

• 4

81 73349 Fpa 0.11 640862 605274

• 6

124 121743 Flim 0.19 637078 557731

• 12

272 535901 SSB2018=MSY B trigger 1.29 586638 181000

• 69

1538 535901 SSB2018=Bpa 1.29 586638 181000

• 69

1538 638528 SSB2018=Blim 1.86 562146 103000

• 82

1851

Advice for 2017, Precautionary approach: Catch ≤ 27 288 t

Boarfish in Subareas 6-8

* Stock status relative to potential reference points is unknown * Assessment indicates the stock biomass has sharply declined in recent years and is currently at the lowest of time series * F fluctuating Catch(2015) = 17 766 t (~ 5% discarding, from demersal gears; all landings from pelagic fishery)

• Assessment uses several survey indices:

1 from acoustic (not fully containing the stock) + 6 from bottom trawl (each considered indicative of trends in its area). Overall index heavily influenced by acoustic survey.

Fishing pressure Stock size 2013 2014 2015 2014 2015 2016 Maximum sustainable yield FMSY Undefined MSY Btrigger Undefined Precautionary approach Fpa, Flim Undefined Bpa, Blim Undefined Management plan FMGT

• Not applicable

SSBMGT

• Not applicable

Qualitative evaluation

• Decreasing
• Decreasing

Category 3 stock: Exploratory assessment with biomass dynamics model: indicative of trends

Index A (2015, 2016) 0.525 Index B (2012, 2013, 2014) 1.391 Index ratio (A/B) 0.378 Uncertainty cap Applied 0.8 Recent advised catch (for 2016) 42 637 t Precautionary buffer Applied 0.8 Catch advice for 2017* 27 288 t Discard rate (2015) 0.05 Wanted catch** corresponding to catch advice 25 924 t

* (Recent advised catch) x cap x (precautionary buffer)

Stock biomass trend from exploratory stock assessment used as stock size indicator: Precautionary buffer applied for the first time this year because stock status relative to potential reference points is unknown and current estimated biomass is the lowest in the time series

Boarfish in Subareas 6-8

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