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Coastal ecosystems of the south coast of Portugal: estuaries and lagoons
Karim ErziniDynamics of Aquatic Ecosystems
13 – 10 - 2008
- Ria Formosa- Guadiana estuary and salt marsh- fish communities, seasonality, interdecadal changes- environmental variability, climate change and fisheries
9.20 9.00 8.80 8.60 8.40 8.20 8.00 7.80 7.60 7.40
Longitude (°W)
36.80
37.00
37.20
Latit
ude
(°N
)
Sagres
LagosPortimão
Albufeira Quarteira
Faro OlhãoFuzeta
Tavira
VRSA
30
100
200
500
Algarve
RIA FORMOSA
?55 km long lagoon?approximately 16,300 hectares ?maximum width of the lagoon is 6 km ?maximum depths of approximately 6 m (low tide) ?6 openings to the sea (barrier islands)?tidal range: between 1.5 and 3.7 m?very good water circulation (50% renewal every tidal cycle)
?extensive sea grass beds and saltmarsh?90% of the area is a Natural Park?of European importance for biodiversity, Natura2000 site,important bird area (IBA), RAMSAR?recreation, fishing, bait collection?aquaculture
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Ria Formosa (western end)
Praia de Faro Max. width ~ 6 km
• species composition, relative abundance, time of settlement,and size at settlement in different habitats • the distribution and abundance of juvenile stages of fishes, particularly Sparidae· habitat use and preferences in the inshore environment· factors controlling distribution, abundance, and survivorship· the dispersal / migration / recruitment from the inshore habitats to the deeper water fishing grounds· present day distributions, abundances, and species composition compared with those of 13 to 15 years ago
RECRUITMENT OF SEA BREAMS (SPARIDAE) AND OTHER COMMERCIALLY IMPORTANT SPECIES IN THE ALGARVE (SOUTHERN PORTUGAL)
OBJECTIVES:
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Source: Whitfield, A.K. and M. Elliott. 2002. Fishes as indicators of environmentaland ecological changes within estuaries: a review of progress and some suggestionsfor the future. J. Fish Biology 61(Suppl. A): 229-250.
Use of fishes as indicators of biological integrity
I. Fish Community Studies
Objectives:
•Long-term changes in the fish communityof the Ria Formosa, biodiversity•Recruitment, habitat use•Spatio-temporal distribution•Impacts on the fish community
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1) Areas of strong coastal influence: BR, BP2) Secondary canals/interior areas: IC, ID, IP3) Main canals: CB, CD, CP
SAMPLING STRATEGY
Beachseine
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Sampling locations with the 25 m beach seine(monthly, 479 samples, Oct 2000-Oct 2001)
Beam trawl
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Beam trawl sampling locations
Riley push net
Sample site Sea bed Deep in shalow water Vegetation % coveringPn1 Sand-mud 0.5 0Pn2 Sand 0.5 0Pn3 Sand-mud 0.5 0Pn4 Mud-sand 1 90Pn5 Sand-mud 1 90Pn6 Mud-sand 1 90
Sample location bottom depth %plant cover
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Beam trawl sampling locations
87 different species belonging to 33 families and 52 genera
25 m beach seine
0
4
8
12
16
20
24
1 5 33 8 19 25 12 28 35 3 20 9 22 18 21 7 17 6 23 10 36 4 14 2 24 15 27 11 37 30 13 34 26 29 16 31 32
Locals
Ave
rage
num
ber
of s
peci
es
Mean number of species ? standard deviation at each of the 37sampling stations
Sampling locations
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0
5
10
15
20
25
30
35
40
45
5 18 33 3 8 25 28 1 35 19 12 20 17 4 7 9 22 15 21 23 10 6 34 36 24 2 30 13 11 14 27 16 29 37 26 31 32
Locals
Tota
l nu
mbe
r of
spe
cies
Total numbers of species recorded at each station sampled with the 25 m beach seine.
Sampling locations
0
5
1 0
1 5
2 0
O c t Nov D e c Jan Feb Mar Apr M a y Jun Jul Aug Sep Oct
Month
Av
era
ge
nu
mb
er
of
sp
ec
ies
0
10
20
30
40
50
60
Oct Nov Dec J a n Feb Mar Apr M a y Jun J u l Aug Sep O c t
Month
To
tal
nu
mb
er
of
sp
ec
ies
Mean number of species Total number of species per month per month
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Cluster analysis: monthly data, 25 m beach seine
0
5
10
15
20
25
Mar01 May01 Jul01 Sep01 Nov01 Jan02 Mar02
Month
Ave
rage
num
ber o
f spe
cies
per
sam
ple
loca
tion
Beam trawl: average number of species per month
Total: 72 species and one genus
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Beam trawl: MDS
Riley pushnet: a total of 51 species
Total (n=51)
0
5
10
15
20
25
30
Apr-01 May-01 Jun-01 Jul-01 Aug-01 Sep-01 Oct-01 Nov-01 Dec-01 Jan-02 Feb-02 Mar-02 Apr-02
Num
ber o
f spe
cies
Number of species Avg
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GIS applications: fish density
October 2000
November
December
January
February
March
April
May
June
July
August
September
October 2001
Diplodus vulgaris(two-banded sea bream)
RECRUITMENTAND GROWTH
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Comparative study
Has the fish community changed since the early1980’s?
Methods
• 4 sampling sites (the same as those sampled by CostaMonteiro from 1981-1986)
• same gear (50 m beach seine, 14 mm stretched mesh), fished at low tide
• a sequence of three beach seine sets at each site• monthly sampling over two years (2001-2002)• sub-sampling in the case of large catches• laboratory: identification, weighing and measuring
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Costa Monteiro stations B, C, D and E
Sampling with a 50 m beach seine3 sets at each sampling location, monthly
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Total catches in weight (g) per month at Station B
2001-2002
1980-1984
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0
2000
4000
6000
8000
10000
12000
B C D E
To
tal c
atch
(N)
0
10000
20000
30000
40000
50000
60000
To
tal w
eig
ht (
g)
N
W (g)
Total catch in number and in total weight (in grams) per location.
Species (Station B) 1981-86 2002-02 Species (Station B) 1981-86 2002-02 Species (Station B) 1981-86 2002-02Anguilla anguilla X X Labrus bergylta X Diplodus annularis X X
Atherina spp. X Labrus mixtus X Diplodus bellottii X X
Atherina presbyter X Labrus viridis X Diplodus cervinus X
Halobatrachus didactylus X X Symphodus bailloni X Diplodus puntazzo X X
Belone belone X X Symphodus cinereus X Diplodus sargus X X
Parablennius gattorugine X X Symphodus ocellatus X Diplodus vulgaris X X
Parablennius pilicornis X Symphodus roissali X Lithognathus mormyrus X X
Salaria pavo X Symphodus rostratus X Oblada melanura X X
Arnoglossus thori X X Dicentrarchus labrax X X Pagellus acarne X
Callionymus lyra X Dicentrarchus punctatus X Pagellus bogaraveo X
Callionymus maculatus X Chelon labrosus X X Pagellus erythrinus X
Caranx rhonchus X Liza aurata X X Sarpa salpa X X
Trachurus trachurus X X Liza ramada X X Sparus aurata X X
Alosa fallax X X Liza saliens X X Spondyliosoma cantharus X X
Sardina pilchardus X X Mugil cephalus X Hippocampus guttulatus X
Conger conger X Mullus surmuletus X X Hippocampus hippocampus X X
Engraulis encrasicolus X X Pomatomus saltatrix X Nerophis ophidion X X
Diplecogaster bimaculata X Raja undulata X Syngnathus abaster X X
Gobius couchi X Scorpaena notata X X Syngnathus acus X X
Gobius cruentatus X Scorpaena porcus X Syngnathus typhle X X
Gobius niger X Serranus cabrilla X X Sphoeroides spenglery X
Gobius paganellus X Serranus hepatus X X Torpedo torpedo X
Pomatoschistus microps X Microchirus theophila X Chelidonichthys lucerna X
Pomatoschistus minutus X Monochirus hispidus X Lepidotrigla cavillone X
Pomatoschistus pictus X Solea senegalensis X X Total 47 66Coris julis X Boops boops X X
Ctenolabrus rupestris X Dentex dentex X
Comparison of 1981-1984 with 2000-2002
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Species comparisons
Not considering Gobiidae, Labridae, Liza spp., Syngnathus spp. and Hippocampus spp.:
• 1980-1986: 40 species• 2001-2002: 42 species• 1980-1986: 14 species not in common with 2001-2002• 2001-2002: 12 species not in common with 1980-1986
SamplesPCA
B80 B81
B82
B83
B84
B85-86
B2001
B2002
C80-82
C2001
C2002
D83
D85-86
D2001
D2002
E85-86
E2001E2002
axis 1
-1 -0.5 0 0.5 1
axis
2
-1
-0.5
0
0.5
1
2001-2002
1980-1986
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Cluster analysis results
2001-20021980-1986
MDS
2001B
2002B2001C
2002C
2001D2002D
2001E
2002E
80B
81B
82B
83B
84B
8586B
8082C
83D8586D
8586E
axis 1
-1 -0.5 0 0.5 1
axis
2
-1
-0.5
0
0.5
1
2001-2002
1980-1986
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Conclusions
• Fish diversity appears to have increased from 1981-86 to the present
• Species composition is different• Fish biomass seems stable comparing the two
periods• Individual species numbers/biomass generally
comparable for the two time periods• Variability may be due to variation in recruitment• No negative changes in the fish community ?• What about other factors such as an improvement
in water quality ?
Some new species oroccurrences ......
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II. Spatio-temporal dynamics(tagging studies)
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What are the movements within the Ria and where do the juveniles go when they leave the Ria (generally in Autumn)?
Do juveniles from the Ria colonize the artificial reefs?
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Tagging studies: floy tags
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Species n %Diplodus vulgaris 2606 60.39Dicentrarchus labrax 575 13.33Diplodus sargus 511 11.84Spondyliosoma cantharus 448 10.38Diplodus annularis 100 2.32Pomatomus saltatrix 17 0.39Sparus aurata 11 0.25Dicentrarchus punctatus 10 0.23Diplodus bellottii 10 0.23Mullus surmuletus 6 0.14Raja undulata 4 0.09Caranx rhonchus 3 0.07Raja clavata 3 0.07Boops boops 2 0.05Solea senegalensis 2 0.05Symphodus bailloni 2 0.05Torpedo torpedo 2 0.05Diplodus cervinus 1 0.02Pagellus acarne 1 0.02Sarpa salpa 1 0.02Total 4315
Tagged fish
1 2 3 4 5 6Diplodus vulgaris 189 261 143 31 8 4 2 1Spondyliosoma cantharus 17 23 13 3 1Diplodus sargus 15 17 13 2Dicentrarchus labrax 3 3 3Sparus aurata 1 1 1Total 225 305 173 36 8 5 2 1
Number of times recapturedSpecies
Fish Recaptured
Total Recaptures
< 100 100 to 500 500 to 2000 2000 to 5000 > 5000 Unknown< 1 week 34 39 731 to 2 weeks 20 31 1 522 weeks to 1 month 26 66 6 981 to 3 months 28 30 17 2 773 to 6 months 1 1 2> 6 months 1 1 2Unknown 1 1Total 109 166 25 3 1 1 305
Distance travelled between captures (m)Time between captures
Total
4315 tagged fish, 305 recaptures
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Movements of tagged fish (>500 m)
Artificial reefs
Telemetria acústica
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Tagging studies and future work:
• Limited tag return rate• No tag returns from fish caught outside the Ria• Evidence of high site fidelity of juveniles within the Ria
III. Guadiana Estuary and Castro Marim Saltmarsh
• ichthyofauna• food web• implications of Alqueva dam
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Framework - a project funded by the National Water Institute:
“Study of the environmental conditions in the estuary of the Guadiana river and adjacent coastal zones”
Ecosystem component - characterization / baseline studies:
• species composition and community structure• environmental factors and variability• use of and importance as a habitat for fish• feeding ecology / trophic interactions
Questions:
• Will changes in river flow affect the fish community?• What are the implications for the food web?
Trawl samplinglocations
Beach seine samplinglocations
Lower Guadianaestuary and CastroMarim salt marshsampling locations
• monthly sampling,• at night,• low tide,• lunar phase: last quarter,• professional fishermen,• Sep 2000 - Aug 2001
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Beach seine used in Castro Marim salt marsh creeks
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MethodsLaboratory:• Identification; • Length and weight;• Maturity stage;
• Stomach content analysis.Bibliography:• Complementary studies;• Age at first maturity;• Classification: life cycle, conservation status, tolerance limits, etc...
Data analysis:• Diet indices, prey preferences,• Multivariate analysis.
Classification of fish species
Classification according to reproduction, migration and occurrence: • Resident species;• Marine species using salt marsh/estuary as a nursery;• Occasional (marine);
• Anadramous or catadramous migratory species;• Occasional (freshwater).Habitat:• Salt marsh, lower estuary, middle estuary.Maturity stage:
• Juvenile or adult.
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Classification of fish species cont..
Frequency of occurrence:• Very common or common, rare or occasional, very rareTrophic category:
• Filter feeder, detritus feeder, omnivorous, piscivorous and species feeding on invertebrates
Tolerance:• Fresh water species;• Brackish water species;• Marine.
Pelagic or benthic
Fish community: principal results
• total of 48 species (26 families) of fish in salt marsh and estuary; • predominance of marine species (in particular juveniles);• relatively few resident or anadramous and catadramous migratory
species;• Dominant/characteristic species of the salt marsh: P. microps
(resident); Atherina spp. (resident); Mugilidae (resident and juveniles of marine species), juveniles of Sparidae, S. pilchardus, D. labrax, M. surmuletus(juveniles of marine species);
• Dominant/characteristic species of the lower estuary: H. didactylus, D. sargus, D. vulgaris, D. labrax, S. vulgaris, S. senegalensis;
• Lower diversity in the middle estuary;• Greater diversity and abundance in the summer;• Importance of salinity.
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Lusitanian toadfish (Halobatrachus didactylus)
Mullets (Liza aurata, L. ramada)
Sand goby (Pomatochistus microps)
Sea breams (e.g. Diplodus sargus)
European bass (Dicentrarchus labrax, D. punctatus)
Red mullets (Mullus surmuletus, M. barbatus)
Soles (Solea senegalansis, S. vulgaris)
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SETSETSETSETNOVNOV
NOV
JANJAN
JAN
JAN
FEV
FEVFEV
MARMAR
MAR
MAR
ABR
ABR
ABRABR
MAIMAI
MAIMAI
MAIJUN
JUNJUN
JUN
JUL
JULJUL
JULAGOAGOAGO
AGO
axis 1
-1 -0 .5 0 0.5 1
axi
s 2
-1
-0 .5
0
0 . 5
1
Summer
Salt marshCannonical correspondence analysis
Maximum river runoff,lowest salinity
Aal
Af
AanAth
Bb
Cl
C c
Dl
Dp
Da
Db
DsDv
Ee
Fh
GnHd
L a LrL s
M c
Mug
M b
M s
Pg
Ps
Pm
Pmin
Sp
Ss
Sc
Sa
Tt
axis 1
-1 -0 .5 0 0 .5 1
axi
s 2
-1
-0 .5
0
0 .5
1
Freshwater species
Brackish and resident speciesJuveniles / marine
species
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Aal
A f
AanAth
Bb
Cl
C c
Dl
Dp
Da
Db
DsDv
Ee
Fh
GnHd
L aLrLs
M c
Mug
Mb
M s
Pg
Ps
Pm
Pmin
Sp
Ss
Sc
Sa
Tt
Temp
Sal
axis 1
-1 -0 .5 0 0 . 5 1
axis
2
-1
-0.5
0
0.5
1
SETSETSETSETNOVNOV
NOV
JANJAN
JAN
JAN
FEV
FEVFEV
MARMAR
MAR
MAR
ABR
ABR
ABRABR
MAIMAI
MAIMAI
MAIJUN
JUNJUN
JUN
JUL
JULJUL
JULAGOAGOAGO
AGOT e m p
Sal
axis 1
-1 -0.5 0 0.5 1
axis
2
-1
-0.5
0
0.5
1
Summer
Floods, maximum runoff
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Aal
Af
AanAth
Bb
Cl
Cc
Dl
Dp
Da
Db
DsDv
Ee
Fh
GnHd
La LrLs
Sc
Sa
Tt
SETSETSETSET
NOVNOV
NOV
JANJAN
JAN
JAN
FEV
FEVFEV
MARMAR
MAR
MAR
ABR
ABR
ABRABR
MAIM A I
MAIMAI
MAIJUN
JUNJUN
JUN
JUL
JULJUL
JULAGOAGOAGO
AGOT e m p
Sal
axis 1
-1 -0.5 0 0.5 1
axi
s 2
-1
-0 .5
0
0 . 5
1
Freshwater
Marine,juveniles
Brackish, residents
Aal Aan
Ath
Bb
Cl
Dl
Dp
Da
Db
Ds
Dv
Ee
Fh
LaLrLs
Sc
Sa
JAN
ABR
ABR
ABRABR
MAIMAI
M A I
MAI
MAI
JUN
JUNJUN
JUN
JUL
JUL
JUL
JULAGO
AGO
AGO
AGO
axis 1
-0.5 0 0.5
axi
s 2
0
0.5
Zoom...
Principally juveniles:sparidae and sea basses
Salinity
Temp
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Feeding Ecology and Food Web
• sampling period: September 2000 - August 2001• 1415 stomachs of the most important species
MDS based on mean seasonal values of CN%
Soles
Sea basses
Red mullets
Sea breams
Toadfish
Moronidae
MullidaeSparidae
Batrachoididae
Amphipoda
C. maenas
C. crangon
Insecta
Echinoidea
Other Teleostei
P. serratus
Algae, sea grass
Polychaeta
Autumn
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Soleidae
Moronidae
Batrachoididae
C. maenas
C. crangon
Gobiidae
Other Crustacea
Other Teleostei
P. serratus
Polychaeta
Winter
Soleidae
Moronidae
Sparidae
Batrachoididae
Amphipoda
C. maenas
C. crangon
Gobiidae
Other Teleostei
Fisheggs
Algae, sea grass
Polychaeta
Cerastoderma spp.Spring
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Moronidae
Mullidae
SparidaeAmphipoda
C. crangon
Gobiidae
Insecta
OtherTeleostei
P. serratus
Algae, sea grass
Polychaeta
Summer
Soleidae
Moronidae
MullidaeSparidae
Batrachoididae
Amphipoda
C. maenas
C. crangon
Gobiidae
Other Teleostei
Fish eggs
P. serratus
Algae, sea grass
Polychaeta
Cerastoderma spp.All Year
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Xarroco
Robalos
Sargos
Linguados
Salmonetes
Tainhas
Carcinusmaenas
Gobius sp
Crangon crangon
Palaemon serratus
Amphipodes
Algas
Gastrópodes
Poliquetas
Camarões
Pulga-do-mar Matériaorgânica
Crustáceos
Isópodes
Fitoplâncton
Zooplâncton
Moluscos
Clupeídos
Sea bassesPhytoplankton
ZooplanktonMullets
Small pelagics
Gastropods
Polychaetes
Organicmatter
Crustaceans
Molluscs SolesShrimps
Toadfish
Algae,sea grasses
Amphipods
Sea breams
Red mullets
Isopods
Preferential prey: Secondary prey: Literature:
Food web partly based on data from other studies
Alqueva dam:
-storage capacity of 4.1 x 109 m3
-increase of approximately 43% in terms of volumeretained in dams
- reduction in mean flow (60% of the 50 year mean)
- less organic material, nutrients- decreased primary production- fewer high flow events- deterioration of salt marsh ?
- decrease in essential fish habitat?- changes in food web?- coastal fisheries ?
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IV. Climate change and fish and fisheries of the Algarve (southern Portugal)
• Changes in the fish fauna of the Ria Formosa lagoon (1980-1986 to 2000-2002)
• Records of rare or unusual catches from local commercial fisheries
• Relationships between Algarve landings and environmental variables
An important transition zone:
Algarve coastAlgarve coast
- Mediterranean influence
- NE Atlantic influence
- Central east Atlantic influence
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Implications of increasing temperatureImplications of increasing temperature
• Changes in the geographic distribution
• Occurrence of new, warm water species
• Disappearance of more temperate species
• Reproduction
Changes in the fish fauna of the Ria Formosa
• more species in 2000-2002 (114 versus 89)• stable biomass• increase in subtropical species (30% versus 17.5%)• e.g. Synaptura lusitanica, Microchirus boscanionand Bothus podas
Not considering Gobiidae, Labridae, Liza spp., Syngnathus spp. and Hippocampus spp.:
• 1980-1986: 40 species• 2001-2002: 42 species• 1980-1986: 14 species not recorded in 2001-2002• 2001-2002: 12 not recorded in 1980-1986
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New records:
Sparisoma cretense (Mediterranean parrotfish)
Source:Abecasis et al. (2005) JMBA2 – Biodiversity Records (published online)
Species not recorded in 2000-2002
Sand eel: temperate species that has retreated north.
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Other indicators of change:Other indicators of change:
- New species reported by commercial fishers:
Synodus saurus(from the Mediterranean)
Galeoides decadactylus(from NW Africa)
Environmental variables and landingsEnvironmental variables and landings
- analysis of relationships between landings and explanatory variables such as river flow, SST and NAO- strong relationships for some species such as sardine and shrimp
-2
-1
0
1
2
3
1970 1975 1980 1985 1990 1995 2000Ano
Cau
dal e
Cap
tura
de
sard
inha
(X-m
édia
/des
vio
padr
ão)
Desembarques de sardinhaCaudal (ano hidrológico)
Year
Standardized sardine landings and Guadiana river flow
See: Erzini, K. 2005. Trends in NE Atlantic landings (southern Portugal): identifying the relativeimportance of fisheries and environmental variables. Fisheries Oceanography 14: 195-209.
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For some species such as Octopus vulgaris, no significant relationships
050
100150200250300350400
Jan-87Ja
n-88Ja
n-89Jan
-90Jan
-91Ja
n-92Ja
n-93Jan
-94Jan
-95Jan
-96Jan
-97Jan
-98Jan
-99Jan
-00Jan
-01Ja
n-02Jan
-03Jan
-04
Month
LPU
E (
kg/d
ay)
0
200004000060000
80000100000120000
Jan-87
Jan-88
Jan-8
9Jan
-90Jan
-91Ja
n-92Jan
-93Jan
-94Ja
n-95Jan
-96Jan
-97Jan
-98Jan
-99Ja
n-00Jan
-01Ja
n-02Ja
n-03Jan
-04
Month
To
tal l
and
ing
s (k
g)
Trend component Seasonal component
Fishery, rather than environmentally driven dynamics?
Changing scenarios: new species, new Changing scenarios: new species, new opportunities?opportunities?
Warmer waters could mean greater availability of large pelagics.
--White marlinWhite marlin ((Tetrapturus albidusTetrapturus albidus) and ) and blue blue marlinmarlin ((Makaira nigricansMakaira nigricans) are summer visitors ) are summer visitors (> 20ºC);(> 20ºC);
-- collaboration with Big Game Fishing Association collaboration with Big Game Fishing Association of Portugal: data collection (catches, feeding of Portugal: data collection (catches, feeding ecology, environmental data)ecology, environmental data)
White marlin Blue azul
Vilamoura, Vilamoura, blueblue marlinmarlin, 750kg, , 750kg, AugustAugust 1993, >20ºC1993, >20ºC
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Dados: Coelho & Erzini (2006); Moura et al. (2007.)Map: adapted from “Atlas do Ambiente Digital – Instituto do Ambiente”
• Example of a species with a limited reproductive period (winter) in the Algarve
• with an increase of 1 -2ºC, it will probably no longer reproduce in Algarve waters
Raja undulata
ALGARVE
0
1
2
3
4
5
6
Verão Outono Inverno PrimaveraEstação
GS
I nas
Fêm
eas
PENICHE
0
1
2
3
4
5
Verão Outono Inverno PrimaveraEstação
GS
I nas
Fêm
eas
Changing scenarios: loss of commercial species?
Sarpa salpa
1980-19842000-2001
Importance of longterm monitoring:• Ria Formosa: annual beach seine surveys since 2000• Arade river estuary: annual surveys since 2004 • Sportfishing (large pelagics)• Collaboration with commercial fishermen
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Bibliography
Abecasis, D.; Bentes, L.; Ribeiro, J.; Machado, D.; Oliveira, F.; Veiga, P.; Gonçalves, J.M.S. & Erzini, K. (2006) First record of the Mediterranean parrotfish, Sparisoma cretense in Ria Formosa (south Portugal). JMBA2 - Biodiversity records.
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