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ICES Advice on fishing opportunities, catch, and effort Celtic Seas and Greater North Sea ecoregions Published 30 June 2016 ...

ICES Advice on fishing opportunities, catch, and effort

Celtic Seas and Greater North Sea ecoregions Published 30 June 2016

Sea bass (Dicentrarchus labrax) in divisions 4.b–c, 7.a, and 7.d–h (central and southern North Sea, Irish Sea, English Channel, Bristol Channel, and Celtic Sea)

ICES stock advice

ICES advises that when the precautionary approach is applied, there should be zero catch (commercial and recreational) in 2017.

Stock development over time

SSB peaked in 2010 and has been declining since. Spawning-stock biomass (SSB) is now below Blim. The fishing mortality (F) shows an increasing trend but has declined slightly in recent years. Recruitment has been very poor since 2008; however, the 2013 estimate shows above-average recruitment.

Figure 5.3.57.1 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. Summary of stock assessment (weights in thousand tonnes). Total landings, including commercial landings and recreational estimates. Fishing mortality is shown for the combined commercial and recreational fisheries. Predicted recruitment values are not shaded.

Stock and exploitation status

Table 5.3.57.1 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. State of the stock and fishery relative to reference points (RP).

Fishing pressure

Stock size

2013

2014

2015

2014

2015

2016

Maximum

FMSY

Undefined

MSY Btrigger

Below trigger

sustainable yield

Reduced

Precautionary

Fpa,

Undefined

Bpa, Blim

approach

Flim

reproductive

Management

FMGT

Not applicable

SSBMGT

Not

plan

applicable

Qualitative

Above any

Not

evaluation

candidate RP

applicable

ICES Advice 2016, Book 5

Published 30 June 2016 ICES Advice on fishing opportunities, catch, and effort

Catch options

Table 5.3.57.2 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. The basis for the catch options.

Variable	Value	Notes	Source
F ages 5–11 (2016)	0.30	F2015. Commercial fishery F = 0.22; recreational fishery F = 0.08.	ICES (2016a)
SSB (2017)	6 219 t	Short-term forecast	ICES (2016a)
Rage 0 (2014, 2015, and 2016)	6 469 thousands	Geometric mean 1985–2013	ICES (2016a)
Total catch (2016)	Unknown
Total landings (2016)	2 305 t	Commercial + recreational	ICES (2016a)
Discards (2016)	Unknown

Table 5.3.57.3 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. The catch options. Weights are in tonnes. The option of TAC changes are not presented, since there is no TAC for sea bass.

			Total		Commercial			Recreational					Commercial						%SSB
			landing		Commercial			Recreational			Total F		Commercial		Recreational		SSB		%SSB
	Rationale		landing		landings			landings	Basis		Total F		F		Recreational		SSB		change
	Rationale		s		landings			landings	Basis		(2017)		F		F (2017)		(2018)		change
			s		(2017)			(2017)			(2017)		(2017)		F (2017)		(2018)		*
			(2017)		(2017)			(2017)					(2017)						*
			(2017)
	Precautionary	0		0			0		F = 0	0		0		0		7583		21.9
	approach	0		0			0		F = 0	0		0		0		7583		21.9
	approach
	MSY								FMSY
	approach^#								FMSY
	approach^#
		2036		1475			560		F2016	0.30		0.22		0.08		5845			−6.0
									SSB2018 =
									Blim
									SSB2018 =
	Other								Bpa = MSY
	Other								Btrigger
	options^								Btrigger
	options^	1672		1212			460		0.8 × F2016	0.24		0.18		0.07		6152			−1.1
		1672		1212			460		0.8 × F2016	0.24		0.18		0.07		6152			−1.1
		1483		1074			408		0.7 x F2016	0.21		0.15		0.06		6312		1.5
		1288		933			355		0.6 × F2016	0.18		0.13		0.05		6478		4.2
		882		639			243		0.4 × F 2016	0.12		0.09		0.03		6824		9.7
		453		328			125		0.2 × F. 2016	0.06		0.04		0.02		7192		15.6
*SSB in 2018 relative to SSB in 2017.
# The MSY approach option was left blank because FMSY has not been appropriately defined.
^The Blim, Bpa, and MSY Btrigger options were left blank because Blim cannot be achieved in 2018 even with zero catch advice.

Basis of the advice
Table 5.3.57.4 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. The basis of the advice.
	Advice basis					Precautionary approach.
	Management plan					There is no management plan for sea bass in this area.

Quality of the assessment

There are uncertainties in the assessment because of inaccuracies in the catch data, particularly recreational catches. The point estimate of 1500 tonnes for the recreational catch is based on different surveys over a few years, and the assumption of using a constant F to reconstruct the time-series of catches adds uncertainty to the assessment. Fishery sampling rates over time have been variable for all countries.

The estimates of F and SSB have been rescaled as a result of the addition of age and length composition data introduced during the recent inter-benchmark (ICES, 2016b). The overall trends remain similar.

The two survey data series for the eastern English Channel, which is only a small part of the total stock area, provide good estimation of recruitment. However, a change in vessel and survey design in the Channel Ground Fish Survey led to the 2015

2 ICES Advice 2016, Book 5

ICES Advice on fishing opportunities, catch, and effort Published 30 June 2016

value not being included in this assessment. The very weak recruitment from 2008 to 2012 estimated in the assessment is confirmed by the surveys and by reduced catches of young fish by the UK and French fisheries. All the input data to the assessment and additional information (catch per unit effort in the French fishery) are indicative of a declining trend of biomass.

Stock identity remains poorly understood and tagging studies are ongoing. Survival rates of sea bass discarded from commercial vessels or released by anglers are poorly known.

Figure 5.3.57.2 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. Historical assessment results (includes assumed long-term average recruitment for 2013 onwards in both assessments). The basis of the assessment changed in 2015 when the stock was benchmarked (ICES, 2015b).

Issues relevant for the advice

The emergency measures in 2015 reduced pelagic trawl catches of seabass and also bycatch of seabass in other fisheries. The fishing mortality in 2016 is assumed to be the same as in 2015 in the catch forecast and the results show that even with zero catch in 2017 the stock will stay below Blim in 2018. However, additional management measures have been introduced for 2016 which may result in fishing mortality below the assumed. A sensitivity analysis carried out by ICES indicates that with 30% reduction in F in 2016, which is considered plausible given the additional management measures for 2016, and zero catch in 2017 the stock would increase to just above Blim in 2018. Given that the stock would be estimated to remain near Blim and taking into account the uncertainties in the assessment and forecast, ICES considers that its advice for zero catch in 2017, aiming to bring the stock above Blim in the short term, remains valid even if such a decrease in F in 2016 occurs.

Only Blim and Bpa reference points were re-estimated this year.

A new benchmark is to be conducted for seabass in 2017.

Reference points

Table 5.3.57.5 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. Reference points, values, and their technical basis.

Framework

Reference

Value

Technical basis

Source

point

MSY

MSY Btrigger

12673 t

Bpa

ICES (2016a)

approach

FMSY

Not defined.

Precautionary

Blim

8075 t

Lowest observed spawning-stock biomass.

ICES (2016a)

Bpa

12673 t

Blim × exp(1.645 × σ); σ = 0.274

ICES (2016a)

approach

Flim

Not defined.

Fpa

Not defined.

Management

SSBMGT

Not applicable.

plan

FMGT

Not applicable.

ICES Advice 2016, Book 5 3

Published 30 June 2016 ICES Advice on fishing opportunities, catch, and effort

Basis of the assessment

Table 5.3.57.6 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. The basis of the assessment.

	ICES stock data category		1 (ICES, 2016c)
	Assessment type		Age- and length-based analytical assessment (Stock Synthesis 3; NOAA Toolbox) that uses landings in the
	Assessment type		model and in the forecast.
			model and in the forecast.
			Commercial landings (international landings, ages and length frequencies from catch sampling); one
			recruit survey (UK Solent autumn survey); one bottom trawl survey (Channel Groundfish Survey); growth
	Input data		and maturity data from sampling of commercial catches and surveys; natural mortality (inferred from life
			history parameters and maximum observed ages); recreational fishing mortality estimated for 2012
			inferred from recreational fishery surveys (since 2009).
	Discards and bycatch		Discarding is known to take place but cannot be fully quantified (in the order of 5% in weight).
	Indicators		Catch per unit effort in the French fishery
	Other information		This stock was benchmarked in 2012, 2014 and 2016 (ICES, 2012, 2014, 2016b). A new benchmark is
	Other information		planned for 2017.
			planned for 2017.
	Working group		Working Group for the Celtic Seas Ecoregion (WGCSE)

Information from stakeholders

The North Western Waters Advisory Council (NWWAC) framework for advice for seabass management in Northwestern waters was communicated to the European Commission on 16th of May 2016 (NWWAC, 2016).

History of the advice, catch, and management

Table 5.3.57.7 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. History of ICES advice, the agreed TAC, and the official and ICES estimates of commercial landings. Weights are in thousand tonnes.

					Official
			Predicted catch				ICES commercial

Year	ICES advice			Agreed TAC	commercial
Year	ICES advice		corresp. to advice*	Agreed TAC	commercial		landings
			corresp. to advice*		landings		landings
					landings
2000	-		-	none	2.1		2.4
2001	-	-		none	2.2	2.5
2002	No increase in effort or F	-		none	2.4	2.6
2003	No increase in effort or F	-		none	2.9	3.4
2004	No increase in effort or F	-		none	3.0	3.7
2005	-	-		none	3.2	4.4
2006	-	-		none	3.4	4.5
2007	-	-		none	3.5	4.2
2008	-	-		none	3.0	4.2
2009	-	-		none	4.3	4.0
2010	-	-		none	4.9	4.8
2011	-	-		none	3.9	3.9
2012	No increase in catch	-		none	3.9	4.1
2013	20% reduction in catches (last 3 years’ average)	< 6.0**		none	4.1	4.1
	36% reduction in commercial landings (20%
2014	reduction, followed by 20% precautionary	< 2.707**		none	2.8	2.7
	reduction)
2015	MSY approach	< 1.155***		none	2.1	2.0
2016	MSY approach		≤ 0.541***	none
2017	Precautionary approach	0

Advice prior to 2014 was given for sea bass in the Northeast Atlantic.

Commercial landings.

Total landings (commercial and recreational landings).

4 ICES Advice 2016, Book 5

ICES Advice on fishing opportunities, catch, and effort Published 30 June 2016

History of catch and landings

Table 5.3.57.8 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. Catch distribution by fleet in 2015 as estimated by ICES.

Total catch

Commercial landings

Commercial

Recreational catch

landings other

(2015)

UK and France

discards

(partially reported)

countries

pelagic

bottom

fixed/drift

other

Known to be substantial but

pair

lines

all gears

cannot be fully quantified

trawlers

nets

gears

trawlers

Unknown (in

(surveys indicate total annual

Unknown

36%

22%

20%

13%

the order of

removals by France, UK

5% in weight)

(England), Netherlands, and

Belgium to the order of 1500

2040 tonnes

tonnes in 2012)

Table 5.3.57.9 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. History of commercial landings; both the official and ICES estimated values are presented for each country participating in the fishery (in tonnes). Source: Official landings statistics 1950–2014 and provisional data for 2015, ICES, Copenhagen.

Year	Belgium	Denmark		Germany	France*		UK		Netherlands	Channel Is.		Total	Total ICES

1985	0	0		0	620		105		0	18		743	994
1986	0	0	0		841	124		0		15	980		1319
1987	0	0	0		1226	123		0		14	1363		1980
1988	0	18	0		714	173		8		12	925		1239
1989	0	2	0		675	192		2		48	919		1161
1990	0	0	0		609	189		0		25	824		1063
1991	0	0	0		726	239		0		16	982		1227
1992	0	0	0		721	148		0		36	906		1186
1993	0	1	0		718	230		0		45	994		1255
1994	0	1	0		593	535		0		49	1178		1371
1995	0	1	0		801	708		0		69	1579		1835
1996	0	1	0		1703	563		8		56	2331		3022
1997	0	1	0		1429	561		1		74	2066		2620
1998	0	2	0		1363	488		48		79	1980		2390
1999	0	1	0		NA	685		32		108	826		2670
2000	0	5	0		1522	407		60		130	2124		2407
2001	0	2	0		1619	458		77		80	2236		2500
2002	0	1	0		1580	627		96		73	2377		2622
2003	154	1	0		1903	586		163		84	2891		3458
2004	159	1	0		1883	617		191		159	3010		3731
2005	206	1	0		1937	512		327		220	3203		4430
2006	211	2	0		2033	574		308		162	3290		4377
2007	178	1	0		1975	713		376		142	3385		4064
2008	188	0	0		1420	791		380		123	2902		4107
2009	173	0	0		2732	697		395		91	4088		3889
2010	215	4	0		3294	736		399		120	4768		4563
2011	152	2	0		2566	793		395		90	3998		3858
2012	154	3	0		2399	892		376		55	3879		3987
2013	145	5	2		2786	803		370		37	4148		4136
2014	146	1	0		1309	1038		253		37	2784		2682
2015**	40	0	0		1110	683		207		26	2066		2040

Landings since 2000 are ICES estimates.

Preliminary.

ICES Advice 2016, Book 5 5

Published 30 June 2016 ICES Advice on fishing opportunities, catch, and effort

Table 5.3.57.10 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. History of recreational catch and landings estimates provided to ICES by area for each country which has conducted surveys of the fishery. RSE = relative standard error.

Country

Year

Area

Weight /

Kept

RSE

Released

RSE

Total

RSE

Release

Number

rate

Northeast

Weight

2343 t

830 t

3173 t

26%

Atlantic

2009–

ICES

France

2011*,**

Weight

940 t

332 t

1272 t

>26%

26%

Subareas 4 &

2011–2012

Northeast

Weight

3146 t

776 t

3922t

20%

Atlantic

March

North Sea

Number

234000

38%

131000

27%

366000

30%

64%

2010–Feb

North Sea

Weight***

138 t

37%

Netherland

2011

March

North Sea

Number

335000

26%

332000

21%

667000

17%

50%

2012–Feb

North Sea

Weight***

229 t

26%

2013

ICES

380–690

2012^

Subareas 4 &

Weight

230–440 t

150–250 t

26–38%

36–39%

(England)

Belgium

2013

North Sea

Weight

60 t

~ 80% by weight in 2009/2011 was recreational sea angling.

RSE was 26% for subareas 7 and 8 combined; Subarea 7 represented 40% of the total.

93% by weight in 2010/2011 is recreational sea angling; 2012/2013 estimates are sea angling only. ^ Survey covered only recreational sea angling.

Summary of the assessment

Table 5.3.57.11 Sea bass in divisions 4.b–c, 7.a, and 7.d–h. Assessment summary.

			Recruitment						SSB						Landings		Mean F
	Year		Age 0		High		Low				High		Low
									tonnes						tonnes		Ages 5–11
			thousands

1985		355		688		22		13506		15916		11095		2216		0.151
1986		686		1304		68		12242		14455		10029		2441		0.181
1987		7868		10019		5717		11155		13170		9140		3041		0.241
1988		6188		8980		3395		10154		11975		8332		2286		0.183
1989		37654		42653		32655		10054		11767		8340		2149		0.181
1990		3213		5675		750		9481		11179		7783		1930		0.185
1991		6106		8685		3527		8497		10200		6794		1987		0.218
1992		9044		11823		6265		7507		9186		5827		1935		0.217
1993		4163		6297		2030		7738		9372		6104		2196		0.2
1994		13202		16811		9593		9710		11260		8160		2689		0.167
1995		20048		23846		16249		12825		14363		11286		3359		0.181
1996		1024		1984		65		14725		16362		13087		4527		0.249
1997		23272		27659		18885		14309		16016		12601		4027		0.238
1998		8440		12906		3975		13592		15343		11842		3728		0.232
1999		22970		28426		17514		13219		15001		11437		4042		0.248
2000		11067		15228		6906		13313		15122		11503		3861		0.222
2001		12605		17961		7250		14090		15985		12195		4005		0.222
2002		20114		26871		13357		14768		16768		12767		4232		0.219
2003		21068		27267		14869		15807		17900		13714		5162		0.254

6 ICES Advice 2016, Book 5

ICES Advice on fishing opportunities, catch, and effort								Published 30 June 2016

	2004	13829	18886	8772	16458	18622	14294	5516	0.259
	2005	10283	14278	6288	17024	19247	14802	6208	0.292
	2006	11175	15204	7147	16759	19062	14455	6120	0.294
	2007	8606	12416	4796	16619	19001	14236	5869	0.273
	2008	5362	8575	2150	17294	19779	14810	6009	0.264
	2009	4508	6922	2094	18021	20710	15331	5810	0.252
	2010	865	1739	0	18215	21217	15213	6386	0.291
	2011	2845	4533	1158	17001	20386	13616	5536	0.275
	2012	1595	2812	378	15738	19578	11899	5487	0.305
	2013	10576	20107	1046	13781	18125	9438	5383	0.36
	2014	6469*			11057	15896	6219	3680	0.313
	2015	6469*			9084	14348	3820	2839	0.303
	2016	6469*			7320	12874	1765
	Average	9942	13812	6790	13158	15631	10685	4021	0.241

Long-term geometric mean.

Annual recreational landings consistent with recreational F(5–11) of 0.08, estimated by assessment model.

Sources and references

EU. 2015. Council Regulation (EU) 2015/104 of 19 January 2015 fixing for 2015 the fishing opportunities for certain fish stocks and groups of fish stocks, applicable in Union waters and, for Union vessels, in certain non-Union waters, amending Regulation (EU) No 43/2014 and repealing Regulation (EU) No 779/2014

EU. 2016. How is the EU protecting sea bass? Online article available at: http://ec.europa.eu/fisheries/cfp/fishing_rules/sea-bass/index_en.htm. [Accessed 1 June 2016].

ICES. 2012. Report of the Inter-Benchmark Protocol on New Species (Turbot and Sea Bass; IBPNew 2012), 1–5 October 2012, Copenhagen, Denmark. ICES CM 2012/ACOM:45. 239 pp.

ICES. 2014. Report of the Inter-Benchmark Protocol for Sea Bass in the Irish Sea, Celtic Sea, English Channel, and Southern North Sea (IBP–Bass). By correspondence. ICES CM 2014/ACOM:45. 218 pp.

ICES. 2016a. Report of the Working Group for the Celtic Seas Ecoregion (WGCSE), 4–13 May 2016, ICES Headquarters, Copenhagen, Denmark. ICES CM 2016/ACOM:13.

ICES. 2016b. Report of the Second Inter-Benchmark Protocol for Sea Bass in the Irish Sea, Celtic Sea, English Channel, and Southern North Sea (IBP–Bass2). By correspondence. ICES CM 2016/ ACOM:31. 191 pp.

ICES. 2016c. Advice basis. In Report of the ICES Advisory Committee, 2016. ICES Advice 2016, Book 1, Section 1.2.

NWWAC. 2016. Framework for advice – Seabass management in North Western Waters; 13 May 2016. North Western Waters Advisory Council.

http://www.nwwac.org/_fileupload/Opinions%20and%20Advice/Year%2011/Seabass/NWWAC_Framework_advice_Seabass_May-2016_EN.pdf.