GFCM SCSA, Izmir 22-26 Sept 2008Sardine GSA06 Bellido et al Fishery Assessment of Sardine Stock...

GFCM SCSA, Izmir 22-26 Sept 2008 Sardine GSA06 Bellido et al

Fishery Assessment of Sardine Stock GSA06 (Northern Spain)

Bellido, J.M.1, Quintanilla, L.2, Giráldez, A.2, Torres, P2., Ceruso, C.1, Alemany, F.3, Iglesias, M.3

1 Instituto Español de Oceanografía. Centro Oceanográfico de Murcia. C/ Varadero 1. San Pedro del Pinatar. 30740. Murcia. Spain.

2 Instituto Español de Oceanografía. Centro Oceanográfico de Málaga. Puerto Pesquero s/n. Apdo 285. Fuengirola. 29640. Málaga. Spain.

3 Instituto Español de Oceanografía. Centro Oceanográfico de Baleares. Muelle del Poniente s/n. Apdo 291. Palma de Mallorca 07015. Spain.


Introduction

Fishery assessment by VPA methods of the Spanish sardine stock GSA06 is reported.

VPA Lowestoft software suite was used and XSA was the assessment method. A separable VPA was also run as exploratory analysis for both stocks.

Stochastic short term projections were also produced.


GFCM GSA- 06 Northern Spain

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Burriana

Sagunto

ValenciaCullera

Gandia

AlteaXavea

TorreviejaSan Pedro

Denia

Santa Pola

Roses

LlançaCambrils

Sant Feliu de GuixolsBlanes

Arenys De MarMataro

BarcelonaVillanova i La Geltrú

Tarragona

L´Ametlla De Mar

San Carlos de la RapitaVinaros

Castellón

GSA06 NORTHERN SPAIN

100 0 100 Kilometers

N

Landings and sampling ports (in blue)


Assessment Data GSA06

Landings time series 1994-2007.

ALK 2004-2006, combined ALK for 1994-2003. Length Distributions 1994-2007.

Biological sampling 2004-2007 for Maturity at age and Weight-Length relationships.

Tuning data from acoustic survey ECOMED and Commercial Fleet off Barcelona, Tarragona, Castellón and Torrevieja.


XSA Input Data GSA06

Landings (caton)

0

10000

20000

30000

40000

50000

60000

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Years

To

nn

es

Maturity (matprop) and Natural Mortality (natmor)

0.38

0.85

0.99 1.00 1.00 1.00

0.33 0.33 0.33 0.33 0.33 0.33

0.00

0.20

0.40

0.60

0.80

1.00

0 1 2 3 4 5

Ages

Proportion mature atyear start

Natural Mortality

Catch in number (canum)

0200000

400000600000

80000010000001200000

14000001600000

18000002000000

1994 1996 1998 2000 2002 2004 2006

Years

Num

ber

in th

ousa

nds

5+

4

3

2

1

0

Mean Weight in catch (weca) and stock (west)

0.000

0.010

0.020

0.030

0.040

0.050

0.060

0.070

0.080

0.090

0 1 2 3 4 5

Ages

Ind

ivid

ual

wei

gh

t (k

g)

19941995199619971998199920002001200220032004200520062007


XSA Input Data GSA06

Tuning Fleet ECOMED

0%

20%

40%

60%

80%

100%

2003 2004 2005 2006 2007

Years

Ag

e G

rou

p P

erce

nta

ge

5+

4

3

2

1

0

Tunig Fleet Castellón

0%

20%

40%

60%

80%

100%

1994 1996 1998 2000 2002 2004 2006

Years

Ag

e G

rou

p P

erce

nta

ge

5+

4

3

2

1

0

Tuning Fleet Barcelona

0%

20%

40%

60%

80%

100%

1994 1995 1996 1997 1998 1999 2000

Years

Ag

e G

rou

p P

erce

nta

ge

5+

4

3

2

1

0

Tuning Fleet Tarragona

0%

20%

40%

60%

80%

100%

2001 2002 2003 2004 2005 2006 2007

Years

Ag

e G

rou

p P

erce

nta

ge

5+

4

3

2

1

0

Tuning Fleet Torrevieja

0%

20%

40%

60%

80%

100%

2003 2004 2005 2006 2007

Years

Ag

e G

rou

p P

erce

nta

ge

5+

4

3

2

1

0


Assessment Model

Separable VPA – as Exploratory tool.

VPA - XSA (Extended Survivors Analysis) as

assessment tool.


Diagnostics Separable GSA06

Log catchability residual plots. No unusual pattern of residuals and conflicts between ages.

SEPARABLE

-3

-2

-1

0

1

2

3

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

0/ 1 1/ 2 2/ 3 3/ 4


XSA Assessment

Main Settings XSA: Fbar 1-3. Age 2 for q stock-size independent and age 3 for q

independent of age. Fshrinkage = 0.500 and S.E. for fleet terminal estimates ≥

0.300

XSA Diagnostics. Residuals by Fleet. Estimations of Survivors by age and fleet.


Fleet Diagnostics GSA06

ECOMED

0.47 -0.14 0.29 0.54 -1.15

-1.22 -1.07 1.77 -1.31 1.79

1.80 -0.55 -1.34 0.52 -0.40

2.23 -0.31 -2.08 0.97 -0.77

3.02 0.56 -0.58 1.52 -0.43

-1

0

1

2

3

4

5

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

BARCELONA

-0.25 -0.22 0.17 0.14 0.06 0.09 -0.12

-0.20 0.05 0.11 0.29 0.02 0.18 -0.42

-0.13 0.12 0.34 0.43 0.13 -0.67

-0.13 -0.04 0.49 0.28 0.21 -0.12 -0.53

-0.65 -0.41 0.17 -0.09 -0.22 0.11 -0.36

-1

0

1

2

3

4

5

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

CASTELLÓN

-0.32 0.04 0.18 0.09 -0.08 -0.61 0.49 0.91 -0.26 -0.20 -0.08 0.49 -1.07 0.33

-0.51 0.03 0.02 0.06 -0.46 -0.48 0.27 1.10 -0.33 -0.05 0.60 0.05 -0.33 -0.34

-0.42 -0.19 0.20 0.16 -0.30 -0.19 0.12 0.97 -0.01 0.12 -0.09 0.10 -0.22 -0.50

-0.26 -0.19 0.55 0.19 -0.32 0.10 1.54 0.13 -0.27 0.14 0.26 -0.36 -1.44

-1.02 -0.71 0.42 -0.59 -1.78 -0.54 -0.42 1.17 -0.59 -0.80 -0.66 -0.71 -1.00 -2.23

-1

0

1

2

3

4

5

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

TORREVIEJA

-1.28 0.59 2.19 -0.16 -1.36

-0.40 -0.36 0.28 0.15 0.31

-0.46 -0.62 0.09 0.26 0.71

-0.19 -0.19 0.03 0.01 0.33

0.94 1.17 0.48 0.33 0.51

-1

0

1

2

3

4

5

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

TARRAGONA

0.33 0.35 -0.06 0.07 0.19 -0.47 -0.37

0.45 0.25 -0.28 0.11 0.01 -0.32 -0.18

0.69 -0.03 -0.75 -0.69 0.31 0.16 0.33

0.72 0.05 -1.10 -0.64 0.39 0.29 0.31

-0.21 0.35 -0.71 -1.03 0.02 0.26 0.20

-1

0

1

2

3

4

5

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008


Estimated Survivors by Fleet GSA06

Age 0 - Estimated Survivors by Fleet

0

500000

1000000

1500000 FLT01-ECOMED (thousa

FLT02-CASTELLON (tho

FLT03-BARCELONA (tho

FLT04-TARRAGONA (tho

FLT05-TORREVIEJA (th

P shrinkage mean

F shrinkage mean

Survivors at end of year

Age 0 - Scaled weights by fleet

0

0.25

0.5 FLT01-ECOMED (thousa



FLT04-TARRAGONA (tho FLT05-TORREVIEJA (th

P shrinkage mean

F shrinkage mean


0

200000

400000






P shrinkage mean

F shrinkage mean



0

0.25





P shrinkage mean

F shrinkage mean




0

50000

100000





F shrinkage mean



0

20000

40000





F shrinkage mean



0

0.25






F shrinkage mean


0

0.25






F shrinkage mean




0

10000





F shrinkage mean



0

0.25






F shrinkage mean


Stock Summary GSA06

FISHING MORTALITY

0.00.30.50.81.01.31.51.82.0

1994 1996 1998 2000 2002 2004 2006

Year

RECRUITMENT

0

500

1000

1500

2000

2500

3000

1994 1996 1998 2000 2002 2004 2006

Year

TOTAL BIOMASS AND SSB

0

20000

40000

60000

80000

100000

120000

140000

1994 1996 1998 2000 2002 2004 2006

Year

TOTAL BIOMASS

SSB

TOTAL LANDINGS

0

10000

20000

30000

40000

50000

60000

1994 1996 1998 2000 2002 2004 2006

Year

SSB - RECRUITMENT

0

500

1000

1500

2000

2500

3000

0 20000 40000 60000 80000 100000

SSB at 1st of J anuary


Short term projections

Deterministic Projections for three years (2008 to 2010).

MFDP software (Multi-Fleet Deterministic Projections). Settings: Recruitment Geometric mean:

GSA06 - RGM1997-2006 = 1603 millions. F statu quo is Fishing Mortality Average last three years

and Reference ages 1-3, i.e. average Fbar last 3 years. GSA06 - Fstatu quo = 0.80.


Results GSA06 Short term projection

2008Biomass SSB FMult FBar Landings

73952 50791 1 0.7964 23258

2009 2010Biomass SSB FMult FBar Landings Biomass SSB

78297 54706 0 0 0 107720 83278. 54706 0.1 0.0796 3308 104076 79727. 54706 0.2 0.1593 6410 100668 76410. 54706 0.3 0.2389 9319 97480 73311. 54706 0.4 0.3185 12051 94497 70414. 54706 0.5 0.3982 14616 91702 67704. 54706 0.6 0.4778 17027 89084 65168. 54706 0.7 0.5575 19295 86628 62793. 54706 0.8 0.6371 21429 84324 60568. 54706 0.9 0.7167 23438 82161 58482. 54706 1 0.7964 25332 80129 56526. 54706 1.1 0.876 27118 78218 54689. 54706 1.2 0.9556 28803 76421 52964. 54706 1.3 1.0353 30394 74729 51342. 54706 1.4 1.1149 31898 73134 49817. 54706 1.5 1.1946 33320 71631 48382. 54706 1.6 1.2742 34666 70213 47030. 54706 1.7 1.3538 35941 68874 45756. 54706 1.8 1.4335 37149 67608 44554. 54706 1.9 1.5131 38295 66411 43420. 54706 2 1.5927 39384 65278 42348


Conclusions - Assessment

Landings in 2007 were 23,980 t, showing a decrease from that of 2006 (29,350 t). The time series shows an stable pattern, although it is at low level. The lowest landings of the assessed time series is 2002.

Fishing mortality is at a moderate-high level (F07=0.83), showing a rather plane pattern from 2002 onwards.

Recruitment in 2007 (R07=1478 millions) increases slightly from that of 2006 (1172 millions). The trend of the recruitments is so important as they can affect seriously to the stock health.

Both Total Biomass in 2007 (TB=72,860 t) and Spawning Stock Biomass in 2006 (SSB=51,220 t) show an stable pattern with a slight recovery from the lowest observed SSB (Bloss=36,830 t, in 2002), although both TB and SSB are still at a rather low level.


Conclusions - Catch forecasting

statu quo F (Fbar05-07=0.80, RGM1997-2006 = 1603 millions)

landings are predicted to be close to 23,200 t in 2008 and 25,300 t in 2009.

Total biomass will be 74,000 t in 2008, 78,300 t in 2009 and 80,100 t in 2010, what account for an increase on stock numbers.

SSB will also increase from 50,800 t to 56,500 t from 2008 to 2010.

This exploitation pattern to maintain F statu quo 2007-09 will produce a slightly gain and continuing the increasing trend, helping the recovery of the stock from its lowest value in 2002.


Conclusions - Management considerations

No reference points for sardine can be suggested at this point. Further research is aimed to produce Reference Points and Harvest Control Rules for the sardine GSA06 fishery.

This fishery is considered as fully exploited.

We consider fishing effort should not increase beyond the current levels. This should allow to maintain the current levels of Fishing mortality.


Further work

Reference points

Harvest Control Rules.


Thanks for your attention.

Comments are welcomed.

Dr. Jose Mª Bellido ([email protected])

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GFCM SCSA, Izmir 22-26 Sept 2008Sardine GSA06 Bellido et al Fishery Assessment of Sardine Stock...

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