Advice and Scenarios Database



Witch (Glyptocephalus cynoglossus) in Subarea 4 and divisions 3.a and 7.d (North Sea, Skagerrak and Kattegat, eastern English Channel)
StockCode
wit.27.3a47d
Assessment Year
2020
Stock Category
1
Purpose
Advice
Published
Stock Assessment Key
13549
Link to Advice Sheet
https://doi.org/10.17895/ices.advice.5936






Catch scenarios


Basis
Total catch^^
Projected landings
Projected discards*
Ftotal ages 4–8
Ftotal ages 4–8
SSB^
SSB^
% SSB change **
% advice change ***
2021 2021 2021 2021 2022 2021 2022 2022 2022
(t) (t) (t) (ratio) (ratio) (t) (t) (%) (%)
ICES Basis Advice
MSY approach: FMSY 1733 1681 53 0.154 0.154 5490 5476 -0.25 5
Other scenarios
FMSY-upper 2295 2228 67 0.21 0.21 5327 5006 -6 39
FMSY-lower 1243 1210 33 0.108 0.108 5635 5898 4.7 -25
F = 0 0 0 0 0 0 5976 6992 17 -100
Fpa 2195 2131 65 0.2 0.2 5353 5082 -5.1 33
Flim 3135 3033 103 0.3 0.3 5074 4341 -14.4 90
Fsq 2215 2150 66 0.2 0.2 5348 5063 -5.3 34
SSB (2022) = Blim 4942 4793 149 0.53 0.53 4508 3069 -32 199
SSB (2022) = Bpa 2629 2547 82 0.24 0.24 5222 4745 -9.1 59
SSB (2022) = MSYBtrigger 2629 2547 82 0.24 0.24 5222 4745 -9.1 59
Rollover advice 1651 1603 48 0.146 0.146 5515 5561 0.85 0




Symbol Footnotes
* Including BMS landings. assuming recent discard rate (average of 2017—2019).
** SSB in 2022 relative to SSB in 2021.
*** Advice value for 2021 relative to the advice for 2020 (1651 tonnes).
^ SSB is estimated at spawning time (1 July).