GENERAL FISHERIES COMMISSION FOR THE MEDITERRANEAN (GFCM)
SCIENTIFIC ADVISORY COMMITTEE (SAC)
Sub-Committee of Stock Assessment (SCSA)
Working Group on Small Pelagics
Izmir, Turkey, 22-26 September, 2008
G.S.A. 16, South of Sicily
Trends in anchovy and sardine populations
(1998-2008)
I.A.M.C. C.N.R. – Mazara del Vallo (Italy)
Catch-effort data
Catch-effort data collection was originated in 1997 through a EU-DGXIV funded study
coordinated by I.A.M.C.-C.N.R. This study firstly evidenced the socio-economic importance
of small pelagic species in the “South of Sicily” sector of the Sicilian Channel (G.S.A. 16 of
General Fisheries Commission for the Mediterranean - FAO).
11°
12°
13°
14°
15 °
16°
38°
38°
Marsala
Mazara del Vallo
Sciacca
SICILIA
P. Empedocle
BATIMETRIA
Licata
Siracusa
37°
50
37°
16
100
200
Pozzallo
400
1000
2000
3000
13
36°
36°
ISTITUTO DI RICERCHE
SULLE RISO RSE MARINE
E L'AMBIENTE
15
35°
35°
11°
12°
13°
14°
15 °
16°
Catch-effort data
Catch-effort census data have been collected at Sciacca port since April 1997.
Sciacca is the most important base port for the landing of small pelagic species along the
southern Sicilian coast. It was estimated to account for about 2/3 of total small pelagic
landings in GSA 16. Two fishing gears are operated: purse seine and pelagic pair trawl.
11°
12°
13°
14°
15 °
16°
38°
38°
Marsala
Mazara del Vallo
Sciacca
SICILIA
P. Empedocle
BATIMETRIA
Licata
Siracusa
37°
50
37°
16
100
200
Pozzallo
400
1000
2000
3000
13
36°
36°
ISTITUTO DI RICERCHE
SULLE RISO RSE MARINE
E L'AMBIENTE
15
35°
35°
11°
12°
13°
14°
15 °
16°
Catch-effort data
Landings from purse seiners and pelagic pair trawlers are almost exclusively (>90%)
composed by sardines (Sardina pilchardus) and anchovies (Engraulis encrasicolus). The main
fishing area was located on the southern Sicilian shelf, from Mazara to Licata.
11°
12°
13°
14°
15 °
16°
38°
38°
Marsala
Mazara del Vallo
Sciacca
SICILIA
P. Empedocle
BATIMETRIA
Licata
Siracusa
37°
50
37°
16
100
200
Pozzallo
400
1000
2000
3000
13
36°
36°
ISTITUTO DI RICERCHE
SULLE RISO RSE MARINE
E L'AMBIENTE
15
35°
35°
11°
12°
13°
14°
15 °
16°
Sciacca small pelagic fishery
Sciacca small pelagic fishery (purse seiners and pelagic trawlers) is composed by: 15 pairs of
pelagic trawlers (Sciacca is the only port along the southern Sicilian coast with this type of
fishery); 17 purse seiners from different base ports: 5 Sciacca, 3 Trapani and 9 Terrasini.
Pairs of pelagic trawlers:
N.
Nome Unità
Matr.
N.
Nome Unità
Matr.
1
Nuovo Risorto
3PE288
9
Nuovo Lealdo
3PE604
1
Nuovo Oriule
3PE523
9
Nuovo S. Pietro
3PE650
2
Maria di Fatima
3PE406
10
San Francesco C.
3PE550
2
Umberto Luigi
3PE417
10
Nuova Luigia
3PE659
3
Loretta Pulcini
3PE412
11
Sacro Cuore di Gesù
3PE623
3
Calogero Padre C.
3PE625
11
Serena
3PE646
4
San Giuseppe Secondo
3PE470
12
Santo Padre
3PE622
4
Valbruna
3PE492
12
Ardito
3PE630
5
Orizzonte Secondo
3PE476
13
Gaetano Catania
3PE602
5
Pietro Padre Primo
3PE564
13
Portofino
3PE636
6
Maria Stella del Mare
3PE488
14
Immacolata Concezione
3PE593
6
Azzurra
3PE592
14
Costantino
3PE599
7
Antonino Padre
3PE612
15
Pietro il Grande
3PE529
7
Abramo
3PE648
15
Città di Viareggio
3PE590
8
Freccia dell'Est
3PE509
8
Angelita
3PE606
Purse seiners:
N.
Porto
Nome Unità
Matr.
Porto di sbarco
1
Trapani
Sansone Primo
TP2136
Mazara
2
Trapani
Azzurra
TP2094
Sciacca
3
Trapani
Padre Pio
TP2123
Sciacca
4
Terrasini
Uragano
3PA625
Mazara
5
Terrasini
S. Guglielmo
3PA628
Mazara
6
Terrasini
Maria Madre
3PA630
Mazara
7
Terrasini
Trilona
3PA536
Mazara
8
Terrasini
Nuovo San Silvestro
3PA620
Mazara
9
Terrasini
Lorenzo Padre
3PA596
Mazara
10
Terrasini
Folgore
3PA632
Mazara
11
Terrasini
Santa Rita
7PA1838
Sciacca
12
Viareggio
Angelo Padre
VG3821
Sciacca
13
Sciacca
Padre Peppino
3PE515
Sciacca
14
Sciacca
Maristella
3PE552
Sciacca
15
Sciacca
Pesce Azzurro
3PE626
Sciacca
16
Sciacca
Città di Portoferraio
3PE664
Sciacca
17
Sciacca
Rosina
3PE672
Sciacca
During the last decade landings (mainly anchovy) have had
remarkable interannual fluctuations.
Landings
3,500
3,000
2,500
2,000
1,500
1,000
500
0
anchovy
sardine
* 2008
1997
521
1213
1998
1362
1996
1999
127
1233
data updated to June, 30th.
2000
1085
2080
2001
2312
1656
2002
1478
1620
2003
1036
1159
2004
1594
1341
2005
2841
1199
2006
3209
1237
2007
708
1057
2008*
2005
766
r-9
7
g-
97
ot
t-9
ge 7
n9
ap 8
r-9
lu 8
g98
ot
t-9
ge 8
n9
ap 9
r-9
lu 9
g99
ot
t-9
ge 9
n0
ap 0
r-0
lu 0
g00
ot
t-0
ge 0
n0
ap 1
r-0
lu 1
g01
ot
t-0
ge 1
n0
ap 2
r-0
lu 2
g02
ot
t-0
ge 2
n0
ap 3
r-0
lu 3
g03
ot
t-0
ge 3
n0
ap 4
r-0
lu 4
g04
ot
t-0
ge 4
n0
ap 5
r-0
lu 5
g05
ot
t-0
ge 5
n0
ap 6
r-0
lu 6
g06
ot
t-0
6
lu
ap
In the same period total fishing effort maintained quite stable,
though pelagic trawl tended to replace purse seine.
Montly effort - P urs e s eine vs P elag ic trawl
P urs e S eine
P elagic trawl
300
250
200
150
100
50
0
Acoustics
The acoustic surveys were carried out in the Strait of Sicily, on the
continental shelf off the southern coast of Sicily, during the summer (JuneJuly) in 1998, 2000, 2002-2003 and 2005-2008, and during the autumn
(September-October) in 1999, 2000, 2001 and 2004-2005.
Biomass evaluations were carried out by applying a standardised
methodology. Applied equipment included:
• SIMRAD EK 500 two-frequency (38, 120 kHz) split beam echo sounder
(EK60 starting from 2005);
• pelagic trawl net for experimental hauls with the following
characteristics: horizontal opening 13-15 m, vertical opening 6-8 m, mesh
size in the cod-end 10 mm;
• acoustic monitoring systems of trawl net positioning (SIMRAD ITI).
Calibration procedures were carried out on board using a standard copper
sphere.
Results
JULY 2007
Sardine
50
1
Anchovy
50
1
Mazara del Vallo
5
37.5°
2
4
Sicily
Sciacca
6
2
4
6
7
3
100
Porto Empedocle
50
Sicily
Sciacca
5
37.5°
7
3
100
Mazara del Vallo
Porto Empedocle
50
8
8
Licata
9
Licata
9
200
200
10
37°
10
37°
400
400
11
11
Cape Passero
400
Cape Passero
400
12
13
1000
12
19
16
13
1000
15
19
16
17
15
17
18
36.5°
18
36.5°
14
12.5°
13°
13.5°
14°
14.5°
15°
15.5°
14
12.5°
13°
13.5°
14°
14.5°
15°
15.5°
Results
Estimated biomasses (tons) by year and species are shown in the following table:
Echo-survey
Sardine
Anchovy
Total
June 1998
20,000
7,100
27,100
October 1999
33,700
20,200
53,900
July 2000
36,370
11,000
47,370
September 2000
24,800
11,050
35,850
October 2001
10,054
22,950
33,004
July 2002
6,000
11,500
17,500
June 2003
9,500
9,200
18,710
October 2004
17,960
9,820
27,780
July 2005
21,219
20,720
41,921
October 2005
38,795
32,138
70,933
June 2006
10,220
6,370
16,590
June 2007
11,043
6,725
17,768
During the period 1998-2007,
both
sardine
and
anchovy
populations experienced quite
large inter-annual fluctuations.
As regards sardine, biomass
estimates ranged from 6,000
metric tons in July 2002 to over
38,000 metric tons in July 2005.
Anchovy evaluations range from
6,370 metric tons in June 2006 to
about 32,000 metric tons in
October 2005.
Discussion
Sardine population experienced a decreasing trend up to 2002, from 36,000 t in
2000 to just 6,000 t in 2002, with a recovering in the following years up to 2005.
Anchovy and sardine exhibit a similar fluctuation pattern during the last years,
including the “collapse” in 2006, confirmed by the 2007 estimates.
Acoustic biomass estimates (metric tons)
80,000
70,000
60,000
50,000
40,000
30,000
20,000
10,000
0
June 1998
October
1999
July 2000 September
2000
October
2001
July 2002 June 2003
Sardine
Anchovy
October
2004
Total
July 2005
October
2005
June 2006 June 2007
Discussion
Comparisons between landings and biomass show that acoustic estimates
are largely consistent with catch levels recorded in Sciacca port during the
year following the evaluation campaigns.
Anchovy
50,000
4,000
30,000
2,000
20,000
1,000
10,000
0
0
1998
1999
2000
2001
2002
Biomass (t)
2003
2004
2005
2006
2007
Landings (t+1)
Sardine
50,000
4,000
40,000
Biomass
Landings
3,000
3,000
30,000
2,000
20,000
1,000
10,000
0
0
1998
1999
2000
2001
2002
Biomass (t)
2003
2004
Landings (t+1)
2005
2006
2007
Landings
Biomass
40,000
Discussion
Combining acoustic biomass evaluations and reported landings we obtained the
following exploitation rates estimates.
%
Exploitation rate (Anchovy)
50.0
45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1998
1999
2000
2001
2002
2003
2004
2005
2006
2005
2006
2007
landings(t+1)/biomass(t)
%
Exploitation rate (Sardine)
50.0
45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1998
1999
2000
2001
2002
2003
landings(t+1)/biomass(t)
2004
2007
Thank you for your attention