Catch scenarios

Basis	Total catch (2019)	Wanted* catch (2019)	Unwanted* catch (2019)	Ftotal (2019)	Fwanted (2019)	Funwanted^ (2019)	SSB (2020)	% SSB change **	% TAC change ***	% Advice change^^
	2019	2019	2019	2019	2019	2019	2020	2020	2019	2019
	(t)	(t)	(t)	(ratio)	(ratio)	(ratio)	(t)	(%)	(%)	(%)
ICES Basis Advice
MSY approach: FMSY × SSB (2019)/MSY Btrigger	807	753	54	0.41	0.41	0	7671	-3.4	8.4	-25
Other scenarios
F = 0	0	0	0	0	0	0	8841	11	-100	-100
FMSY	866	808	58	0.44	0.44	0	7589	-4.4	16.3	-19
F= FMSY upper × SSB (2019)/MSYBtrigger	807	753	54	0.41	0.41	0	7671	-3.4	8	-25
F= FMSY lower[1] × SSB (2019)/MSYBtrigger	677	633	44	0.33	0.33	0	7857	-1	-9	-37
TAC2018	744	695	49	0.37	0.37	0	7762	-2.2	0	-31
TAC2018 -15%	632	591	41	0.31	0.31	0	7922	-0.199	-15	-41
TAC2018 +15%	857	799	59	0.43	0.43	0	7601	-4.2	15	-20
Fsq (F= F2018)	534	499	34	0.25	0.25	0	8063	-5.4	-28	-50
Fpa	1095	1019	76	0.58	0.58	0	7265	-8.5	47	2
Flim	1415	1311	104	0.81	0.81	0	6824	-14	89	32
SSB2020 = Blim	2034	1867	167	1.38	1.38	0	6000	-24	19	90
SSB2020 = Bpa= MSYBtrigger	153	144	9	0.068	0.068	0	8616	8.5	-79	-86

Symbol	Footnotes
*	“Wanted” and “unwanted” catch are used to describe fish that would be landed and discarded respectively in the absence of the EU landing obligation, based on discard rate of 0- to 1-year-olds, estimated for 2015–2017, assuming that unwanted catch will only be fish under the minimum conservation reference size (MCRS).
**	SSB 2020 relative to SSB 2019.
***	Wanted catch in 2019 relative to TAC in 2018 (695tonnes).
^	In the forecast it is assumed that unwanted catch will only occur at ages 0–1, which is outside the Fbar age range.
^^	Advice value (total catch) for 2019 relative to the advice value for 2018 (1073tonnes).