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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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