scientific cooperation to support responsible fisheries in the adriatic sea general fisheries...
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Scientific Cooperation to SupportResponsible Fisheries in the Adriatic Sea
General Fisheries Commission for the Mediterranean (GFCM)Scientific Advisory Committee (SAC)
Subcommittee on Stock Assessment (SCSA) - Rome, 26-30 September 2005
Anchovy (Engraulis encrasicolus, L.) stock assessment in the Adriatic Sea: 1975-2004
N. Cingolani a, A. Santojanni a, E. Arneri a, A. Berlardinelli a, S. Colella a, F. Donato a, G. Giannetti a, G. Sinovcic b, B. Zorica b, B. Marceta c
a Istituto di Scienze Marine - Sezione Pesca Marittima, Ancona (Italy)b Institute of Oceanography and Fisheries, Split (Croatia)
c Fisheries Research Institute of Slovenia, Ljubljana (Slovenia)
FAO – Fishing area 37: FAO – Fishing area 37:
Mediterranean and Black Sea - GSAMediterranean and Black Sea - GSA
GSA 17GSA 17
Map showing the boundaries of the Adriatic Sea Geographical Sub-Areas (formerly Geographical
Management Units) as originally indicated by the GFCM (solid line) and with the recent revision (dotted line)
Fishing gear used
Mid-water pair trawls (volante)
Purse seines with light (lampara)
08 1 01 08 1 01 TriesteTrieste08 1 02 08 1 02 GradoGrado08 1 03 Marano 08 1 03 Marano
L.L.08 2 00 08 2 00 CaorleCaorle08 2 01 08 2 01
ChioggiaChioggia08 2 02 08 2 02 GoroGoro
08 3 01 P. 08 3 01 P. GaribaldiGaribaldi08 3 02 08 3 02
CesenaticoCesenatico08 3 03 08 3 03 RiminiRimini08 3 04 08 3 04
CattolicaCattolica
ITALY: List ITALY: List of portsof ports
08 4 01 08 4 01 FanoFano08 4 02 08 4 02 AnconaAncona08 4 05 S. 08 4 05 S. Benedetto T.Benedetto T.
08 5 01 08 5 01 GiulianovaGiulianova
= sampling port
= main port
08 6 01 08 6 01 ViesteVieste
SLOVENIA: List of portsSLOVENIA: List of ports
11 1 04 11 1 04 IzolaIzola
11 1 02 11 1 02 KoperKoper
11 1 06 11 1 06 PiranPiran
11 1 08 11 1 08 PortorozPortoroz
= sampling port
03 1 04 03 1 04 NovigradNovigrad
03 1 02 03 1 02 UmagUmag
03 1 06 03 1 06 PorecPorec
03 1 08 03 1 08 RovinjRovinj
CROATIA: CROATIA: List of List of portsports
03 1 12 03 1 12 Pomer Pomer
03 2 04 03 2 04 LovranLovran
03 2 02 M. 03 2 02 M. DragaDraga
03 2 06 03 2 06 IkaIka
03 2 08 03 2 08 OpatijaOpatija
03 2 10 03 2 10 RijekaRijeka03 2 12 03 2 12 KraljevicaKraljevica03 2 14 03 2 14 CrikvenicaCrikvenica
03 2 18 03 2 18 KrkKrk
03 2 16 Novi 03 2 16 Novi VinodolskiVinodolski03 2 20 03 2 20
SenjSenj
03 2 22 03 2 22 CresCres
03 2 24 03 2 24 RabRab
03 2 26 Mali 03 2 26 Mali Losinj Losinj
03 2 28 03 2 28 PagPag
03 3 04 03 3 04 ZadarZadar03 3 06 03 3 06
SaliSali
03 3 08 03 3 08 VrgadaVrgada
03 3 10 03 3 10 BiogradBiograd03 3 12 03 3 12 VodiceVodice
03 3 14 03 3 14 SibenikSibenik03 3 16 03 3 16 PrimostenPrimosten
03 3 18 03 3 18 TrogirTrogir
03 3 20 03 3 20 SplitSplit03 3 22 03 3 22
OmisOmis03 3 24 03 3 24 BracBrac 03 3 26 03 3 26
PostiraPostira03 3 28 03 3 28 MakarskaMakarska
03 3 30 03 3 30 HvarHvar
03 3 34 03 3 34 KomizaKomiza
03 3 36 03 3 36 KorculaKorcula03 3 38 Vela 03 3 38 Vela
LukaLuka
03 3 40 Ploce 03 3 40 Ploce (Metkovic)(Metkovic)03 3 42 Ston 03 3 42 Ston
(Broce)(Broce)
03 3 32 03 3 32 VisVis
03 3 44 Slano03 3 44 Slano
03 3 46 03 3 46 LastovoLastovo
03 3 48 03 3 48 DubrovnikDubrovnik03 3 50 03 3 50
CavtatCavtat
03 3 02 03 3 02 NovigradNovigrad
03 1 10 Pula 03 1 10 Pula (Vodnjan)(Vodnjan)
03 1 14 Labin 03 1 14 Labin (Rabac)(Rabac)
= sampling port
Data collection
Monthly and daily landings
Fishing effort
Biological sampling
Sub-sampling
Catch-weighted length frequency (0.5 cm length class)
CPUE
Standardised fishing effort
Age-length keys
Data obtained
Time series of catch and effort data
Anchovy: catch
0
10000
20000
30000
40000
50000
60000
75 77 79 81 83 85 87 89 91 93 95 97 99 01 03
Year
Cat
ch (
ton
nes
)
main ports small ports east-Adriatic
Adriatic (northern and central) anchovy landed catches
Sardine: catch
0
15000
30000
45000
60000
75000
90000
75 77 79 81 83 85 87 89 91 93 95 97 99 01 03
Year
Cat
ch (
ton
nes
)
main ports small ports east-Adriatic
Adriatic (northern and central) sardine landed catches
0
50000
100000
150000
200000
250000
300000
76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
Year
To
nn
es
Catches
Midy biomass (SAC 2005)
Midy biomass (mean SAC 2003-2004)
The trend of mid-year total (=stock) biomass at sea derived from the VPA performed using data from 1976 to 2004, is compared with the average density (t/nm2) of anchovy, obtainedby acoustic survey in North Adriatic (1987 - 2004; in 2002 and 2003 acoustic survey was not performed)
0
50000
100000
150000
200000
250000
300000
76 78 80 82 84 86 88 90 92 94 96 98 00 02 04
Year
To
nn
es
0
10
20
30
40
50
60
Av.
den
sity
(t/
nm
sq
.)
CatchesMid-year stock biomassAnch. density (echo-survey)
Anchovy GSA17: CPUE calculated for the fleet of Porto Garibaldi(mid-water trawlers or volanti), from 1976 to 2004
0
1
2
3
4
5
6
7
76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
Year
To
nn
es
/ S
td.
fis
hin
g d
ay
s
Anchovy CPUE
'77
'78
'79
'80
'82
'83
'85'86
'96 '81'84
'87'88
'89 '90
'91'92
'93
'94 '95
'97
'98'99
'00'01
'02
'03
'04
0
500000
1000000
1500000
2000000
2500000
0 20000 40000 60000 80000 100000 120000 140000 160000
Spawning biomass in year x (tonnes)
Rec
ruit
s in
yea
r x+
1 (i
nd
ivid
ual
s *
10-4
Anchovy GSA17: empirical relationship between the abundance at seaof spawners in the year n and recruits in the year n+1 (the latter beingreported near the data points), on the basis of VPA estimates
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
76 78 80 82 84 86 88 90 92 94 96 98 00 02 04
Year
Exp
loit
atio
n r
ate
(F /
Z)
Estimated
Threshold (Patterson, 1992)
ConclusionsStock biomass of anchovy dropped at very low level in 1987.After this collapse a slow, but continuous recovery of biomass took place.The present assessment shows a stronger recovery during last two years.Due to high biomass fluctuations of small pelagicsit is recommended to maintain the current level of fishing effort.
0
50000
100000
150000
200000
250000
300000
76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
Year
To
nn
es
Catches
Midy biomass (SAC 2005)
Midy biomass (mean SAC 2003-2004)