project fao-copemed large pelagics relationships of lenth-weigth of bluefin tuna and swordfish for...

Xiphias glaudius (Linnaeus,1758)

Project FAO-COPEMEDLarge Pelagics

COORDINATORJ.M DE LA SERNA (IEO - SPAIN)

PARTICIPANTSM. TAWIL (MBRC-LIBYA), A. FENECH FARRUGIA (MCFS-MALTA),

A.SROUR (INRH-MAROCCO),HATTOUR (INSTM-TUNISIA), J.M DE LA SERNA (IEO - SPAIN)

PUBLISHER

P. RIOJA (FAO -COPEMED)

Large Pelagics Project COPEMED

RESULTS (Period 1998-2003)

1. Enviromental and Hydrographic Description of area under study.

2. Fisheries description and its historical development.

3. Database of catch, effort and size distribution for each species, for each gear (Task I and II of ICCAT).

4. Biological parameters:

1. Biometric relationships of length-weigth for species, gear and area. Analysis of results.

2. Sex ratio for each range of size by species and gear. Comparative analysis.

3. Study of sexual maturity of bluefin tuna and swordfish through gonadosomatic index and histological

analysis.

4. Growth studies of bluefin tuna through the determination of age from dorsal spine sections.

5. Preparation of Standardized Abundace Indices of bluefin tuna and swordfish using GLM.

6. Study of stock of bluefin tuna and swordfich through genetic analysis.

5. Study of by catches of large pelagics in the Mediterranean.

6. Relationship between enviroment and the catches of large pelagics utilizing different gears. Summary of

Investigation.

7. Annual Reporst (5), Final Gibraltar Report 1998-2002.


Fisheries description: description and characteristics of fishingvessels and gear targeting bluefin tuna.

LLJAP-Spain

PS-Spain

TRAP-Libya

PS-Spain PS-Tunisia

Bait Boat-Spain LL-Malta

Vessels targeting bluefin tuna and swordfish with several fishing gears. Note

the high heterogeneity among vessels

Description and characteristics of the different gears targeting tuna


Fisheries description: description and characteristics of fishingvessels and gear targeting swordfish.

LLHB -SpainLLHB – Malta

LLHB - Tunisia Artesanal - Morocco

Vessels targeting bluefin tuna and swordfish with several fishing gears.

Note the high heterogeneity among vessels

Float

4m

1.2 monopilo

Lenght 6m

Flag

Set at every 60 hooksdetected by radar

1.5/1.6 monopilo

1.3 monopilo

(0.9x2)

Bait

(mackerel /squid)

Hook nº 2

(Mustad hook- Norway)

Signal

Bouée

5 à 6 m ; fil N° 140 ; hameçon :2-4

7 à _

8 m

15 à 20 mètres

Fil nylon N° 160-180

Spanish, Tunisian and Maltese longlinestargeting swordfish.


Task data (ICCAT): catches per species, country, gear and time-space distribution.

Bluefin tuna catches for each country using different gears.


Task data (ICCAT): catches per species, country, gear and time-space distribution.

0

20

40

60

80

100

120

140

50

75

100

125

150

175

200

225

250

275

300

325

350

Size

Nu

mb

er

No.=1137

Country:Mc= MarocMt= MaltaLb= LibyaTn= TunisiaSp = SpainIt = ItalyFr = FranciaGr = Grecia

Gear:LL = Surface longlinePS = Purse seineHAND = Hand lineBB = Bait board

0

5

10

15

20

25

30

35

50

70

90

110

13

0

15

0

17

0

19

0

21

0

23

0

25

0

27

0

29

0

31

0

Size

Nu

mb

er

LLHB-Mt

0

5

10

15

20

25

30

35

40

100

115

130

145

160

175

190

205

220

235

250

265

280

Size

Nu

mb

er

TRAP-Lb

HAND-Mc

0

10

20

30

40

50

105

115

125

135

145

155

165

175

185

195

205

215

225

235

Size

Nu

mb

er

LLHB-Lb

0

5

10

15

20

50

70

90

11

0

130

150

170

190

210

230

250

270

290

Size

Num

be

r

HAND-Sp

0

500

1000

1500

2000

2500

3000

50

70

90

110

13

0

15

0

17

0

19

0

21

0

23

0

25

0

27

0

29

0

Size

Nu

mb

er

PS-Sp

PS-Tn

0

500

1000

1500

2000

70

80

90

100

110

120

130

140

150

160

170

180

190

200

Size

nu

mb

er

0

2

4

6

8

10

12

14

16

90

10

5

12

0

13

5

15

0

16

5

18

0

19

5

21

0

22

5

24

0

25

5

27

0

28

5

LH

Nu

mb

er

TUNEZ

ARENAS

TRAP-Tn

0

20

40

60

80

100

120

140

160

180

50

70

90

110

130

150

170

190

210

230

250

270

290

310

330

Size

Nu

mb

er

TRAP-Sp

44

43

42

41

40

39

38

37

36

35

34

33

32

31

30

29

28

44

43

42

41

40

39

38

37

36

35

34

33

32

31

30

29

28

272625242322212019181716151413121110987654321012345678

272625242322212019181716151413121110987654321012345

Length distribution of bluefin tuna for each country using different gears.


Biometric relationships of lenth-weigth of bluefin tuna and swordfish foreach fishery and area. Analysis of variation between different areas for eachgear during same year.

0

50

100

150

200

250

300

350

0 50 100 150 200 250 300

LJFL (cm)

RW

(kg

)

Mor98 Trap Mor98 Hand Mor94 Hand Tun99 Trap Tun00 Ps

Lib00 Trap Spa00 BB

12

3456

7

Key:

1.- 1.53E-04 * RW ^ 2.6381

2.- 2E-05 * RW ^ 2.9957

3.- 4E-04 * RW ^ 2.4295

4.- 3,74869E-05 * RW ^ 2.8589

5.- 7.6416E-06 * RW ^ 3.1316

6.- 9E-05 * RW ^ 2.677

7.- 0.0101 * RW ^ 1.7854

Comparison of bluefin tuna RW- LH relationships for severalfishing gears and seasons.

0

50

100

150

200

250

300

350

0 50 100 150 200 250 300

LJFL (cm)

RW

(kg

)Mor98 GN Spa87 LLHB Mor99 GN Mor99 GN Mor00 GN

12

34

5

Key:

1.- 8.905E-07 * RW ^ 3.555

2.- 2E-06 * RW ^ 3.4009

3.- 3E-06 * RW ^ 3.3033

4.- 1E-06 * RW ^ 3.4959

5.- 3E-06 * RW ^ 3.275

Comparison of swordfish RW- LJFL relationships for several fishinggears and seasons.


Sex ratio for different length classes of bluefin tuna and swordfish for each gear. Analysis of variation and similarities between different gears, time andarea.

LONGLINE_SP (N= 32646); DRIFT NET_MOR (N= 1193)

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

1,1

110 120 130 140 150 160 170 180 190 200 210

length class

propfem_SP ll95% up95% propfem_MOR ll95% up95%

Sex- ratio by length-class and approximate 95% confidence limits for the

Spanish longline fishery and the Moroccan drift net fishery targeting

swordfish.

LONGLINE (N=1598)

0.00.1

0.2

0.3

0.4

0.5

0.60.7

0.8

0.9

1.0

1.1

115 125 13 5 145 155 16 5 17 5 1 85 1 95 2 05 215 225 235 24 5 25 5 265 27 5 28 5

length class

propfem ll95% ul95%

PURSE SEINE (N= 1629)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

11 5 12 5 13 5 14 5 1 55 1 65 1 75 185 195 2 05 215 225 235 24 5 25 5 2 65 27 5 28 5

length class

propfem ll95% ul95%

TRAP (N= 9958)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.80.9

1.0

1.1

1 15 12 5 1 35 1 45 155 165 1 75 185 195 205 21 5 225 235 24 5 25 5 2 65 27 5 28 5

length class

propf em ll95% ul95%

Sex- ratio by length-class and approximate 95%

confidence limits for several gears targeting

bluefin tuna in the Mediterranean Sea and Straits

of Gibraltar.


Sex ratio for different length classes of bluefin tuna and swordfish for each gear. Analysis of variation and similarities between different gears, time andarea.

Female ratios for each length class targeted by different gears Bluefin tuna.

0%

20%

40%

60%

80%

100%

11

0

12

5

14

0

15

5

17

0

18

5

20

0

21

5

23

0

24

5

26

0

27

5

29

0

FL (cm)

%

N=198

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270

Length (cm)

%0

10

20

30

40

50

60

70

80

90

100

100

115

130

145

160

175

190

205

220

235

250

265

280

Fl (cm)

%

No.= 1836 HEMBRAS

0

10

20

30

40

50

60

70

80

90

100

15

0

16

0

17

0

18

0

19

0

20

0

21

0

22

0

23

0

24

0

25

0

26

0

27

0

28

0

TALLA

%

n= 144

0

10

20

30

40

50

60

70

80

90

100

80

95

110

125

140

155

170

185

200

215

230

245

260

275

290

Fl (cm)

%

No.= 247

0

20

40

60

80

100

95

10

5

11

5

12

5

13

5

14

5

15

5

16

5

17

5

18

5

19

5

20

5

21

5

22

5

23

5

24

5

FL(cm)

%

BFT- TRAP-AtlSpain 2000

BFT- TRAP-MedLibya 99 al 02

BFT- PS-MedTunisia 2000-2001 BFT- HAND-E.

Gibraltar /Spain 2002

BFT- LL-MedMalta 2000-2001

BFT- LL- BalearesSpain 2000


Sexual Maturity(I): analysis of gonadosomatic indices of bluefin tunatargeted by different gears.

Bluefin tuna Females GI variations (Spain, 2000)

0

2

4

6

8

10

12

14

16

18

12

6

15

8

16

9

17

6

18

4

18

7

19

1

19

5

19

8

20

2

20

6

21

0

21

3

21

3

22

1

22

4

FL (cm)

GI

Females Bluefin tuna GI (Malta, 2000)

0

2

4

6

8

10

12

14

16

10

7

14

0

15

0

15

3

16

8

18

5

19

2

19

8

21

0

21

0

21

6

22

4

23

0

23

0

23

5

24

0

24

5

25

5

26

3

FL (cm)

GI

GI in traps (Libya, 2000)

0

5

10

15

20

25

112 114 126 142 146 150 150 156 160 167 194 200 200

FL

GI

Bluefin tuna gonodosomatic indices for different gears used in Spain, Malta, Tunisia and Libya.

Female Bluefin tuna GI (Tunis,2000)

0

5

10

15

20

25

30

100 150 200 250 300 350

Longueur à la fourche (cm)

IG


Sexual maturity (II): determination of first sexual maturity of bluefin tuna and swordfish by histological analysis of gonads sampled from Spain-Balearics, Malta, Tunis and Libya.

Prespawning ovaries of bluefin tunas

Prespawning female Spawning female

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,0

20 30 40 50 60 70 80 90 .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..

LJFL (cm)

Pro

p.

Ma

ture

(F

em

ale

s)

0

1

2

3

4

5

6

June July AugustMonths

GS

I

T Males T Females S Females

Postspawning female

Histological analysis of gonad samples of bluefin tuna Histological analysis of gonad samples of swordfish.


Growth studies – Age – Length keys and evaluation of growth obtained fromage determination of bluefin tuna caught by Spanish and Libyan, purseine and Maltese longline.

100

125

150

175

200

225

250

275

4 5 6 7 8 9 10 11 12 13 14 15 16

Age (years)

Fork

length

(cm

)

El-Kebir et al. (2002)

Farrugia & Rguez-Cabello (2001)

Cort (1991)

Compean & Bard (1983)

Present Study

75

100

125

150

175

200

225

250

275

3 4 5 6 7 8 9 10 11 12 13 14 15 16

Age (years)

Fork

length

(c

m)

Rodriguez-Roda (1964)

Mather & Schuck (1960) (westernAtlantic)

Olafsdottir & Ingimundardottir (2003)

Sella 1929

Cort (1991) (spines)

Present study

Comparison of mean fork length by age obtained in the

present and other studies based on vertebra reading

Section of a spiny ray from the first dorsal fry of a bluefin tunaof 150 cm in length. (Course on cut and reading of bluefin tuna

C.O de Málaga).


Abundance Indices: elaboration and standardization of bluefin tuna obtained from Spanish, Morrocon and Tunisian traps.

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

Ye ar

LN

(n/e

ff)

(number) CI 95% CI 95%

Standardized CPUE series in number of fish for the SpanishBFT Trap fishery in the Straits of Gibraltar. Dashed linesindicate 95% confidence bands

Standardized CPUE series in number of fish for the TunisianBFT Trap fishery in the Mediterranean Sea. Dashed linesindicate 95% confidence bands.

-1

-0.5

0

0.5

1

1.5

2

1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

Ye ar

LN

(nu

mb

er/

eff

ort

)

LN CPUE Low er Upper


Abundance Indices: elaboration and standardization of swordfich captured by Moroccon gill nets and Spanish surface longlines in the Mediterranean.

0

50

100

150

200

250

300

350

400

450

500

1988 1990 1992 1994 1996 1998 2000 2002

lcpu1 cpu ucpu1

Evolution of annual standardised abundance indexes,with upper and lower limits of confidence level at 95%.Swordfish gill nets. Marocco.

0

2

4

6

8

10

12

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

year

cpu

e (n

um

ber

)

low cpue cpue uppercpue

0

20

40

60

80

100

120

140

160

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

year

cpu

e (w

eig

ht)

low cpue cpue uppercpue

Standardized CPUE index (and corresponding 95% confidence limits) in number of fish (upper panel) and weight (lower panel). Surface longline in the Mediterranean. Swordfish


Stock structure-Genetic analysis of bluefin tuna caught by Spanish and Libyan traps, Maltese longline and Tunisian purse seine. Results indicate similar Mediterranean genetic origins.

Neighbor-Joining tree using Kimura two-parameters distance ofthe 11 distinct sequences. Numbers in the internal branchesshowed bootstrap values higher than 75% after 1000 replicates.Calde I, II and III sequences are are usesd as references fortheir own clades

Phylogenetic tree based upon the Neigbor-joining distance of the distinctsequences. The numbers on thebranches show bootstrap valuesexceeding 50%.

Neighbor-joining tree with Tamura-Nei distance ( = 0.27) of the 67 Bluefin tuna haplotypes.Values in the branches


By cath: identification and percentage of by catch caught by Spanish,Moroccan, Tunisian, Maltese and Libyan gear.

Fig

.Nº

8.9

País:Mc= MarruecosMt= MaltaLb= LibiaTn= TúnezSp = EspañaIt = ItaliaFr = FranciaGr = Grecia

Arte:LL = PalangrePS = CercoHAND = Linea de manoBB = Cebo vivo

SW O- C A TALU Ñ A , Sea 1 9 9 9

94,40%

0,60%3,50%2%

TUN

SWO

OTH

SHK

SW O- A LB OR A N , Sea 1 9 9 9

1,20%

74,70%

4,00%

20,10%

TUN

SWO

OTH

SHK

SW O- B A LEA R IC , Sea 1 9 9 9

1% 3,50%1,30%

73,50%

TUN

SWO

OTH

SHK

SW O- M A LT A, Sea 1 9 9 9

5,40%2%

7,50%

85,10% TUN

SWO

OTH

SHK

44

43

42

41

40

39

38

37

34

33

32

31

30

29

28

44

43

42

41

40

39

38

37

36

35

34

33

32

31

30

29

28

272625242322212019181716151413121110987654321012345678

272625242322212019181716151413121110987654321012345

especies asociadas

By catches of surface longlines Spanish and Maltese.


By cath: identification and percentage of by catch caught by Spanish, andMaltese longlines; Moroccan gill nets and Libyan, Tunisian, Spanish andMoroccann traps.

Tuna By-catch in the Spanish SwordfishLongline Fishery(2000)

6,4%

93,3%

0,3%

Tunnus alalunga

Tunnus Thynnus

Katsuwonus pelamis

SharksBy-catch in the Spanish SwordfishLongline Fishery (2000)

73,3%

1,3%

15,6%

9,8%

Alopias vulpinus

Isurus oxyrinchus

Prionacea glauca

Sphyrna

By-catch in the Spanish Swordfish LonglineFishery (2000)

91,0%

2,0%

0,2%1,6%

5,1%

Sw ordfish

Sharks

Billf ishes

Tunas

OTH

Percentage of species caught by the swordfish longline fishery in2000.

Specific composition of thesharks group in the Spanishswordfish fishery in 2000

Moroccan Drift Net By-catches

0,2%

2,7%4,2%

0,6%0,1%

41,3% 51,0%

Sharks

Makaira sp.

Auxis thazard

Euthynnus alletteratus

Sarda sarda

Katsuw onus pelamis

Tunnus thynnus

Percentage (Weight) of the by-catch species in the Morocco DriftNet Fishery.

Tunissian Purseseiner By-catches (2001)

1%

41%

19%

18%

21%

Auxis rochei

Sarda sarda

Orcynopsys unicolor

Euthynnus alletteratus

OTH

By-catch in the Malteese Bluefin TunaLongline Fishery

24%

15%

20%2%

15%

10%

4%10%

Tunnus alalunga

Prionace glauca

Alopias vulpinus

Galeorhinus galeus

Coriphaena hippurus

Scomber scombrus

Sarda sarda

Rubetus pretiosus

Percentage of the main by-catch species caught by theMaltese bluefin tuna longline fishery.

Percentage (Weight) of the Tunisian purseiners by-catches(2001).


Enviromental studies-relationship between surface temperature and CPUE;relationship between wind and bluefin tuna catches.

100,00

516,67

808,33

666,67

35,00 74,20 8,33 8,40 9,00 70,93 86,80 22,60 64,00 15,60 13,20 1,00

23

,1

22

,5

22

,6

22

,3 24

26

,1

26

,3

26 2

6,8

26

,1

25

,3

25

,8

25

,9

26

,1

26

26

0,00

100,00

200,00

300,00

400,00

500,00

600,00

700,00

800,00

900,00

17

/6

20

/6

24

/6

26

/6

10

/7

19

/7

20

/7

21

/7

22

/7

23

/7

24

/7

25

/7

26

/7

27

/7

28

/7

29

/7

CP

UE

W (

kg

/10

00

ho

oks

)

0

5

10

15

20

25

30

Tª(

ºC

)

CPUEW/set Tª(º C)TOTAL CPUEW BY SET AND TEMPERATURE RETIONSHIP

Set date

TOTAL CPUEN BY SET AND TEMPERATURE RELATIONSHIP

0,833,33

5,835,00

0,50

10,60

1,00 1,40 1,40

9,42

12,40

3,00

8,00

2,60 2,20 0,25

23

,1

22

,5

22

,6

22

,3 24

26

,1

26

,3

26 26

,8

26

,1

25

,3

25

,8

25

,9

26

,1

26

26

0,00

2,00

4,00

6,00

8,00

10,00

12,00

14,00

17

/6

20

/6

24

/6

26

/6

10

/7

19

/7

20

/7

21

/7

22

/7

23

/7

24

/7

25

/7

26

/7

27

/7

28

/7

29

/7

Set date

CP

UE

N(n

º/1

00

0 h

oo

ks

)

0

5

10

15

20

25

30

Tª(

ºC

)

CPUEN/set Tª(ºC)

Bluefin tuna catches and temperature relationship in theBalearic Sea (from 26-6-99 to 20-7-99)

05

101520

25303540

455055

6065

W E Otros/Variable

Barbate Conil

Sea surface temperature in the Libyan traps

Percentage of bluefin tuna caught by traps atlatic inrelation to factor wind (1986-2000).

05

1015202530

14-m

ay

17-m

ay

20-m

ay

23-m

ay

26-m

ay

29-m

ay

04-jun

07-jun

10-jun

13-jun

16-jun

19-jun

22-jun

25-jun

28-jun

01-jul

04-jul

Date

Tª

0

100

200

300

400

Num

ber


ACTIVITIES

Statistical activities and sampling.

Collection of catch and effort data for species / gear. (Task I and II ICCAT).

Biological sampling program in ports and on board.

COPEMED working groups on:

Standarization of metthods (CGPM-ICCAT).

Growth: analysis of dorsal spines for age determination..

Reproduction: histological anaysis of gonads of bluefin tuna and swordfish.

Abundance indices: utilizing GLM.

Course stock study following ICCAT methodology.

Stock structure: electronic tagging activity in collaboration with FAIR-UE Proyect.

Presentation of Result:

5 anual Reports of Activities and Results FAO-COPEMED Project Large Pelagics.

Final Report Subprogram Gibraltar 1998-2002.

Elaboration of 40 Scientific Documents COPEMED presented of SCRS de ICCAT during the

period 1999-2003.

Xiphias glaudius (Linnaeus,1758)

Project FAO-COPEMEDLarge Pelagics

COORDINATORJ.M DE LA SERNA (IEO - SPAIN)

PARTICIPANTSM. TAWIL (MBRC-LIBYA), A. FENECH F. (MCFS-MALTA),

A.SROUR (INRH-MAROCCO),HATTOUR (INSTM-TUNISIA), J.M DE LA SERNA (IEO - SPAIN)

PUBLISHER

P. RIOJA (FAO -COPEMED)