Coastal ecosystems of the south coast of Portugal: estuaries and lagoons. Karim Erzini Dynamics of Aquatic Ecosystems

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1 Coastal ecosystems of the south coast of Portugal: estuaries and lagoons - Ria Formosa - Guadiana estuary and salt marsh - fish communities, seasonality, interdecadal changes - environmental variability, climate change and fisheries Karim Erzini Dynamics of Aquatic Ecosystems 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 Latitude ( N) Sagres Portimão Lagos Algarve Albufeira Quarteira Faro Olhão Fuzeta Tavira VRSA Longitude ( W) 1

2 Ria Formosa (western end) Praia de Faro Max. width ~ 6 km RECRUITMENT OF SEA BREAMS (SPARIDAE) AND OTHER COMMERCIALLY IMPORTANT SPECIES IN THE ALGARVE (SOUTHERN PORTUGAL) OBJECTIVES: 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 2

3 Use of fishes as indicators of biological integrity Source: Whitfield, A.K. and M. Elliott Fishes as indicators of environmental and ecological changes within estuaries: a review of progress and some suggestions for the future. J. Fish Biology 61(Suppl. A): I. Fish Community Studies Objectives: Long-term changes in the fish community of the Ria Formosa, biodiversity Recruitment, habitat use Spatio-temporal distribution Impacts on the fish community 3

4 SAMPLING STRATEGY 1) Areas of strong coastal influence: BR, BP 2) Secondary canals/interior areas: IC, ID, IP 3) Main canals: CB, CD, CP Beach seine 4

5 Sampling locations with the 25 m beach seine (monthly, 479 samples, Oct 2000-Oct 2001) Beam trawl 5

6 Beam trawl sampling locations Riley push net Sample Sample location site bottom Sea bed Deep in depth shalow water Vegetation % %plant covering cover Pn1 Sand-mud Pn2 Sand Pn3 Sand-mud Pn4 Mud-sand 1 90 Pn5 Sand-mud 1 90 Pn6 Mud-sand

7 Beam trawl sampling locations 25 m beach seine 87 different species belonging to 33 families and 52 genera 24 Average number of species Sampling Locals locations Mean number of species? standard deviation at each of the 37 sampling stations 7

8 Total numbers of species recorded at each station sampled with the 25 m beach seine Total number of species Sampling Locals locations Mean number of species per month Total number of species per month Average number of species Total number of species Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct 0 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Month Month 8

9 Cluster analysis: monthly data, 25 m beach seine Beam trawl: average number of species per month Total: 72 species and one genus Average number of species per sample location Mar01 May01 Jul01 Sep01 Nov01 Jan02 Mar02 Month 9

10 Beam trawl: MDS Riley pushnet: a total of 51 species Total (n=51) Number of species 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 Number of species Avg 10

11 GIS applications: fish density October 2000 April November December May June Diplodus vulgaris (two-banded sea bream) January July February August March September RECRUITMENT AND GROWTH October

12 Comparative study Has the fish community changed since the early 1980 s? Methods 4 sampling sites (the same as those sampled by Costa Monteiro from ) 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 ( ) sub-sampling in the case of large catches laboratory: identification, weighing and measuring 12

13 Costa Monteiro stations B, C, D and E Sampling with a 50 m beach seine 3 sets at each sampling location, monthly 13

14 Total catches in weight (g) per month at Station B

15 15

16 16

17 N W (g) Total catch (N) Total weight (g) B C D E 0 Total catch in number and in total weight (in grams) per location. Comparison of with Species (Station B) Species (Station B) Species (Station B) Anguilla 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 Coris julis X Boops boops X X Ctenolabrus rupestris X Dentex dentex X 17

18 Species comparisons Not considering Gobiidae, Labridae, Liza spp., Syngnathusspp. and Hippocampusspp.: : 40 species : 42 species : 14 species not in common with : 12 species not in common with Samples PCA 0.5 E2001 D2002 E C2002 C2001 B2002 B2001 axis 2 0 D2001 B82 B84 B85-86 D83 B80 B83 B C80-82 E D axis 1 18

19 Cluster analysis results MDS B 8082C 83D 8586D 84B 81B 8586E axis B 80B 8586B 2002B 2001B 2001C 2002C 2001D 2002E 2001E 2002D axis 1 19

Conclusions Fish diversity appears to have increased from 1981-86 to the

comparing the two periods Individual species numbers/biomass generally

in recruitment No negative changes in the fish community?

20 Conclusions Fish diversity appears to have increased from 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 or occurrences... 20

21 II. Spatio-temporal dynamics (tagging studies) 21

22 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? 22

23 Tagging studies: floy tags 23

24 Tagged fish Species n % Diplodus vulgaris Dicentrarchus labrax Diplodus sargus Spondyliosoma cantharus Diplodus annularis Pomatomus saltatrix Sparus aurata Dicentrarchus punctatus Diplodus bellottii Mullus surmuletus Raja undulata Caranx rhonchus Raja clavata Boops boops Solea senegalensis Symphodus bailloni Torpedo torpedo Diplodus cervinus Pagellus acarne Sarpa salpa Total tagged fish, 305 recaptures Species Fish Total Number of times recaptured Recaptured Recaptures Diplodus vulgaris Spondyliosoma cantharus Diplodus sargus Dicentrarchus labrax Sparus aurata Total Time between Distance travelled between captures (m) captures < to to to 5000 > 5000 Unknown Total < 1 week to 2 weeks weeks to 1 month to 3 months to 6 months > 6 months Unknown 1 1 Total

25 Movements of tagged fish (>500 m) Telemetria acústica Artificial reefs 25

26 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 26

27 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? Lower Guadiana estuary and Castro Marim salt marsh sampling locations Trawl sampling locations Beach seine sampling locations monthly sampling, at night, low tide, lunar phase: last quarter, professional fishermen, Sep Aug

28 Beach seine used in Castro Marim salt marsh creeks 28

29 Methods Laboratory: 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. 29

30 Classification of fish species cont.. Frequency of occurrence: Very common or common, rare or occasional, very rare Trophic 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. 30

31 Lusitanian toadfish (Halobatrachus didactylus) Sand goby (Pomatochistus microps) Mullets (Liza aurata, L. ramada) Sea breams (e.g. Diplodus sargus) European bass (Dicentrarchus labrax, D. punctatus) Red mullets (Mullus surmuletus, M. barbatus) Soles (Solea senegalansis, S. vulgaris) 31

32 axis Salt marsh Cannonical correspondence analysis Summer SET SET JUN JUL JUL MAI JUN JUN JUL MAI MAI AGO AGO MAI MAI AGO JUL NOV NOV Maximum river runoff, lowest salinity ABR ABR ABR MAR MAR MAR MAR JAN JAN JAN JAN FEV FEV axis 1 1 Af Mb Hd Gn 0.5 Juveniles / marine species Ss Fh Db Sa Bb Brackish and resident species PminPs axis 2 0 Ms Sp Ee Cl Ds Ls Dp Lr Mug La Ath Dv Aal Aan Pm Dl Da Pg Sc Mc Cc Tt Freshwater species axis 1 32

33 1 Af Mb Hd Gn Sal 0.5 SsFh Db Sa Bb PminPs axis 2 0 Temp Ms Sp Ee Cl Ds Ls Dp Lr Mug La Ath Dv Aal Aan Pm Dl Da Pg Sc Mc Cc Tt axis 1 1 Sal SET SET NOV NOV axis Temp Summer JUN JUN JUL JUL MAI JUN JUN JUL MAI MAI AGO AGO MAI MAI AGO JUL ABR ABR ABR ABR MAR MAR MAR JAN JAN JAN JAN FEV FEV Floods, maximum runoff MAR axis 1 33

34 axis Temp Sal Marine, juveniles Af Hd SET SET Gn NOV NOV ABR ABR Bb Db Sa Fh ABR JUN JUL JUL MAI JUN JUN Ee Cl Ds Ls Lr DpJUL La Ath MAI MAI Dv AGO AGOAal Aan MAI MAI Dl Da ScAGO JUL JAN Brackish, residents JAN JAN JAN FEV FEV FEV MAR MAR MAR MAR Cc Tt Freshwater axis 1 Zoom... axis Principally juveniles: sparidae and sea basses 0 Temp Salinity Fh Sa DbJUL JUN JUN JUL JUN JUN Ds DpJUL AGO Dv AGO Aal AGO MAI Dl AGO Da Sc Bb MAI Ee Ls MAI La MAI MAI Aan ABR ABR ABR ABR Cl Lr Ath JAN JUL axis 1 34

Feeding Ecology and Food Web sampling period: September 2000 - August 2001 1415 stomachs of the most important species Soles Sea basses Red mullets Sea breams Toadfish MDS based on

35 Feeding Ecology and Food Web sampling period: September August stomachs of the most important species Soles Sea basses Red mullets Sea breams Toadfish MDS based on mean seasonal values of C N % Autumn Algae, sea grass Mullidae Sparidae Echinoidea P. serratus Amphipoda Batrachoididae Polychaeta Other Teleostei C. maenas Insecta Moronidae C. crangon 35

36 P. serratus Winter Batrachoididae Gobiidae Polychaeta Soleidae C. maenas Other Teleostei Moronidae Other Crustacea C. crangon Spring Batrachoididae Cerastoderma spp. Fish eggs Sparidae Algae, sea grass Soleidae Amphipoda Polychaeta C. maenas Other Teleostei Gobiidae Moronidae C. crangon 36

37 Mullidae Summer Algae, sea grass Amphipoda Sparidae P. serratus Polychaeta Gobiidae Moronidae Insecta Other Teleostei C. crangon All Year Mullidae Cerastoderma spp. Fish eggs Sparidae Algae, sea grass Amphipoda Batrachoididae P. serratus Polychaeta Gobiidae Soleidae C. maenas Other Teleostei C. crangon Moronidae 37

38 Food web partly based on data from other studies Sea Robalos basses Sea breams Sargos Palaemon serratus Gobius sp Crangon crangon Phytoplankton Fitoplâncton Amphipods Amphipodes Zooplankton Zooplâncton Red Salmonetes mullets Clupeídos Small pelagics Gastropods Gastrópodes Carcinus maenas Mullets Tainhas Algas Algae, sea grasses Camarões Shrimps Isópodes Toadfish Xarroco Isopods Pulga-do-mar Moluscos Molluscs Crustaceans Crustáceos Linguados Soles Polychaetes Poliquetas Organic Matéria matter orgânica Preferential prey: Secondary prey: Literature: Alqueva dam: -storage capacity of 4.1 x 10 9 m 3 -increase of approximately 43% in terms of volume retained 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? 38

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

39 IV. Climate change and fish and fisheries of the Algarve (southern Portugal) Changes in the fish fauna of the Ria Formosa lagoon ( to ) Records of rare or unusual catches from local commercial fisheries Relationships between Algarve landings and environmental variables Algarve coast An important transition zone: - Mediterranean influence - NE Atlantic influence - Central east Atlantic influence 39

Implications 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

40 Implications 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 (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.: : 40 species : 42 species : 14 species not recorded in : 12 not recorded in

41 New records: Sparisoma cretense (Mediterranean parrotfish) Source:Abecasis et al. (2005) JMBA2 Biodiversity Records (published online) Species not recorded in Sand eel: temperate species that has retreated north. 41

Other indicators of change: - New species reported by commercial fishers: Galeoides decadactylus (from NW Africa) Synodus saurus (from the Mediterranean) Environmental variables and landings -

42 Other indicators of change: - New species reported by commercial fishers: Galeoides decadactylus (from NW Africa) Synodus saurus (from the Mediterranean) Environmental 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 Caudal e Captura de sardinha (X-média/desvio padrão) Standardized sardine landings and Guadiana river flow Desembarques de sardinha Caudal (ano hidrológico) Year Ano See: Erzini, K Trends in NE Atlantic landings (southern Portugal): identifying the relative importance of fisheries and environmental variables. Fisheries Oceanography 14:

For some species such as Octopus vulgaris, no significant relationships LPUE (kg/day) 400 350 300 250 200 150 100 50 0 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Trend

43 For some species such as Octopus vulgaris, no significant relationships LPUE (kg/day) Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Trend component Jan-97 Month Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Total landings (kg) Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Seasonal component Jan-97 Month Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Fishery, rather than environmentally driven dynamics? Changing scenarios: new species, new opportunities? Warmer waters could mean greater availability of large pelagics. -White marlin (Tetrapturus albidus) ) and blue marlin (Makaira nigricans) ) are summer visitors (> 20ºC); - collaboration with Big Game Fishing Association of Portugal: data collection (catches, feeding ecology, environmental data) Vilamoura, blue marlin, 750kg, August 1993, >20ºC White marlin Blue azul 43

44 Changing scenarios: loss of commercial species? Raja undulata GSI nas Fêmeas PENICHE Verão Outono Inverno Primavera Estação 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 Dados: Coelho & Erzini (2006); Moura et al. (2007.) Map: adapted from Atlas do Ambiente Digital Instituto do Ambiente GSI nas Fêmeas ALGARVE Verão Outono Inverno Primavera Estação 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 Sarpa salpa

45 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. Almeida, C., R. Coelho, M. Silva, L. Bentes, P. Monteiro, J.Ribeiro, K. Erzini and J.M.S.Gonçalves 2008 Use of different intertidal habitats by faunal communities in a temperate coastal lagoon. Esturarine, Coastal and Shelf Science (in press) Curtis, J., Ribeiro, J., Erzini, K. and A. Vincent A conservation tradeoff? Interspecific differences in seahorse responses to experimental changes in fishing effort. Aquatic Conservation: Marine and Freshwater Ecosystems 17: Erzini, K Trends in NE Atlantic landings (southern Portugal): identifying the relative importance of fisheries and environmental variables. Fisheries Oceanography 14: Oliveira, F., Erzini, K. and J.M.S. Gonçalves Feeding habits of the deep-snouted pipefish Syngnathus typhle Linnaeus, Estuarine Coastal and Shelf Science 72: Ribeiro, J., Bentes, L., Coelho, R., Gonçalves, J.M.S., Lino, P. and K. Erzini. Seasonal, tidal and diurnal changes in fish assemblages associated with seagrass and sand habitats of the Ria Formosa lagoon (Portugal) Estuarine Coastal and Shelf Science 67: Ribeiro, J., C.C. Monteiro, P. Monteiro, L. Bentes, R. Coelho, J.M.S. Gonçalves, P.G. Lino and K. Erzini Long-term changes in fish communities of the Ria Formosa coastal lagoon (southern Portugal) based on two studies made 20 years apart. Estuarine, Coastal and Shelf Science, 76: Sá, R., Bexiga, C., Veiga, P., Vieira, L. and K. Erzini Feeding ecology and trophic relationships of the main fish species of the lower Guadiana river estuary and Castro Marim and Vila Real de Santo António salt marsh. Estuarine Coastal and Shelf Science 70: Veiga, P., Vieira, L., Bexiga, C., Sá, R. and K. Erzini Fish assemblages of the Castro Marim saltmarsh (southern Portugal): structure and temporal variation. Estuarine Coastal and Shelf Science 70:

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