Cod in Subarea 4, divisions 6.a and 7.d, and Subdivision 20 (North Sea, West of Scotland, eastern English Channel and Skagerrak)

StockCode (Assessment Component)

cod.27.46a7d20 (Southern Substock)

Assessment Year

2025

Stock Category

Purpose

Advice

Published

Stock Assessment Key

19662

Link to Advice Sheet

https://doi.org/10.17895/ices.advice.27202566

Status: valid

Advice Component

Advice Category*

Advice Type*

Advice Unit*

AdviceValue*

Advice Value Lower Range

Advice Value Upper Range

Wanted Catch

Wanted Catch Lower Range

Wanted Catch Upper Range

Advice Sentence*

Northern shelf cod consists of three substocks (Northwestern, Southern, and Viking) which mix and are caught together. ICES advises that when the maximum sustainable yield (MSY) approach and precautionary considerations are applied, there should be zero catch in 2026 for all substocks. 

ICES advises that when the MSY approach is applied to the Northwestern and Viking substocks without precautionary considerations, and the MSY approach with precautionary considerations is applied to the Southern substock catches in 2026 should be no more than 8670 tonnes, 3610 tonnes and 0 tonnes respectively. As the three substocks are caught together, this will result in a higher probability (67%) for the Southern substock of remaining below Blim. The available evidence suggests this risk to the Southern substock may be reduced by fishing in quarter one (January-March), when the three stocks are thought to mainly separate to the areas shown in Figure 2. ICES is not able to quantify the degree of mixing between substocks in quarters 2-4 and any level of catch of Southern substock will increase the probability of being below Blim in 2027, predicted to be 44% even with zero catch. However, the indirect effects of more intensive fishing in Q1 have not been quantified and may lead to undesirable outcomes, such as alterations in the selection pattern.

Advice Released Date*

Advice Applicable From*

Advice Applicable Until*

TAF Link

Management Alignment

MP WebLink

Management Plan Ownership

Link To Evaluation

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Catch scenarios

Basis	Total catch	Ftotal (ages 2–4)	Spawning-stock biomass (SSB)	% SSB change*	% advice change**	Probability of SSB < Blim^^
	2026	2026	2027	2027	2026	2027
	(t)	(ratio)	(t)	(%)	(%)	(%)
ICES Basis Advice
Maximum sustainable yield (MSY) approach and precautionary considerations: F = 0	0	0	14605	58	-100	44
Other scenarios
F2025 × 0.35***	1744	0.214	12048	30	-22	67
MSY approach: SSB (2027) = Blim	399	0.044	14002	51	-82	50
FMSY × SSB (2026)/MSYBtrigger	933	0.108	13219	43	-58	56
FMSY lower × SSB (2026)/MSYBtrigger	595	0.067	13706	48	-74	53
FMSY	1866	0.231	11878	28	-17	69
FMSY lower	1221	0.144	12769	38	-46	61
FPA	3312	0.464	9839	6.3	47	85
SSB (2026) = MSY Btrigger = BPA^
F = F2025	3958	0.591	8905	-3.8	76	89
SSB(2027)=SSB(2026)	3717	0.542	9259	0	65	87

Symbol	Footnotes
*	SSB 2027 relative to SSB 2026 (9259 t).
**	Advice value for 2026 relative to the corresponding advice value for 2025 (2248 t).
***	F multiplier that equates approximately to the cumulative substock advice, 12 288 t (1744 t + 7619 t + 2925 t), when following the MSY approach for Northern and Viking substocks and MSY approach with precautionary considerations for Southern substock independently and equates to a total catch of 12280 t (0 t + 8670 t + 3610 t).
^	BPA and MSY Btrigger cannot be achieved in 2027, even with zero catches.
^^	The probability of SSB being below Blim in 2027. This probability relates to the short-term probability of SSB < Blim and is not comparable to the long-term probability of SSB < Blim tested in simulations when estimating fishing mortality reference points.