Advice and Scenarios Database



Whiting (Merlangius merlangus) in Subarea 4 and Division 7.d (North Sea and eastern English Channel)
StockCode
whg.27.47d
Assessment Year
2021
Stock Category
1
Purpose
Advice
Published
Stock Assessment Key
15613
Link to Advice Sheet
https://doi.org/10.17895/ices.advice.7885






Catch scenarios


Basis
Total catch
Total projected landings*
Total projected discards**
Total IBC**
Human Consumption catch
Total F (ages 2–6)+
F (projected landings. ages 2–6)
F (projected discards .ages 2–6)
F (IBC. ages 2–6)++
SSB
% SSB change^
% advice change^^
2022 2022 2022 2022 2022 2022 2022 2022 2022 2023 2023 2023
(t) (t) (t) (t) (t) (t) (ratio) (ratio) (ratio) (t) (%) (%)
ICES Basis Advice
MSY approach: F = FMSY 88426 51276 34184 2966 85460 0.371 0.259 0.097 0.015 238600 -9 236
Other scenarios
F = FMSY upper 91703 53247 35508 2947 88755 0.385 0.269 0.1 0.015 236247 -9.9 249
F = FMSY lower 70169 40293 26808 3068 67101 0.293 0.202 0.075 0.015 251709 -4 167
F2022 = 0 (IBC only) 3439 0 0 3439 0 0.015 0 0 0.015 299843 15 -87
F2022 = F2021 44890 25087 16594 3209 41681 0.185 0.124 0.046 0.015 269861 3 70
Rollover TAC 29595 15884 10416 3294 26300 0.12 0.076 0.028 0.015 280846 7.2 12.5
15% TAC decrease (27.4 only) 25672 13524 8832 3316 22355 0.103 0.064 0.024 0.015 283664 8.2 -2.4
15% TAC increase (27.4 only) 33518 18245 12001 3273 30246 0.136 0.088 0.033 0.015 278028 6.1 27
0.75 × F2021+++ 35036 19159 12613 3264 31772 0.143 0.093 0.035 0.015 276937 5.7 33
1.25 × F2021+++ 54961 31145 20663 3153 51808 0.228 0.155 0.058 0.015 262629 0.2 109
Fpa 91703 53247 35508 2947 88755 0.385 0.269 0.1 0.015 236247 -9.9 249
Flim 169645 100134 66999 2512 167133 0.718 0.512 0.191 0.015 180279 -31 545
SSB (2023) = Bpa = MSY Btrigger 219997 130424 87343 2230 217767 0.933 0.669 0.249 0.015 143905 -45 736
SSB (2023) = Blim 276086 164164 110004 1917 274169 1.173 0.84 0.314 0.015 103560 -60 950




Symbol Footnotes
* Marketable landings.
** The split of catch between landings. discards. and industrial bycatch (IBC) in 2022 was done using partial age-dependent fishing mortalities as a forecasting input. Partial Fs were calculated based on total F-at-age and the numbers-at-age per catch category as estimated in the assessment (average exploitation pattern of the three most recent years).
^ SSB 2023 relative to SSB 2022.
^^ Total catch 2022 relative to the advice value 2021 (26 304 tonnes).
+ Total F is calculated as the sum of partial fishing mortalities.
++ F (IBC) is assumed to be constant in all scenarios at status quo value.
+++ Multiplier only applied to F (discards) and F (landings). with F (IBC) constant.