Study ID 467

Spatial and temporal organisation of a coastal lagoon fish community

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Realm: Marine
Climate: Temperate
Biome: Temperate shelf and seas ecoregions
Central latitude: 40.675834
Central longitude: -8.684562
Duration: 4 years, from 1987 to 1999

819 records

72 distinct species

Across the time series Atherina boyeri is the most frequently occurring species

Citation(s):

Pombo, L. & Rebelo, J. E. (2002) Spatial and temporal organization of a coastal lagoon fish community-Ria de Aveiro, Portugal. Cybium, 26(3), 185–196.Pombo, L., Elliott, M. I. & Rebelo, J. E. (2005) Environmental influences on fish assemblage distribution of an estuarine coastal lagoon, Ria de Aveiro (Portugal). Scientia Marina, 69(1), 143–159.Pombo, L., Rebelo, J. E. & Elliott, M. (2007) The structure, diversity and somatic production of the fish community in an estuarine coastal lagoon, Ria de Aveiro (Portugal). Hydrobiologia, 587(1), 253–268.Rebelo, J. E. (1992) The ichthyofauna and abiotic hydrological environment of the Ria de Aveiro, Portugal. Estuaries, 15(3), 403–413.

Methods

Fish were collected monthly between August 1987 and July 1988 at ten selected stations (Fig. 1) near the mouth of the lagoon (BAR GAF and SJA) at the extremities of the main channels (ARE CAR OVA and VAG) approximately in the middle of the longest channel (TOR) in the Laranjo zone (LAR) and in the main freshwater (highly organically enriched) zone (RIO). Diurnal samples were taken in triplicate at low spring tides with the chincha a traditionally used purse-seine-type net of the region (Nobre et al. 1915) and with 2.5 m fixed-frame-opening trawl in a 1.5-min tow. The area enclosed by the chincha was approximately 1500 m s at all stations except at VAG where it was 800 m s due to the narrow topographic configuration. Fishes were preserved by freezing. At the laboratory each specimen was identified according to the taxonomic keys of Whitehead et al. (1986) measured (total length) and weighed. The abundance biomass and species richness of the ichthyofauna were determined by sampling station. Fish were collected monthly from December 1996 to November 1997 at nine selected stations (Fig. 1) near the mouth of the lagoon (BAR GAF and SJA) at the edges of the main channels (ARE CAR and VAG) in the main freshwater area highly organically enriched (RIO) in the area showing the highest levels of industrial pollution (LAR) and approximately in the middle of the longest channel (TOR). Samples were monthly taken in triplicate at low tide with a chincha a traditional beach-seine (Fig. 2). The area enclosed by the chincha was approximately 1000 m2 at all stations except at VAG where it was 800 m 2 due to a narrow topographic configuration. Stretched mesh sizes in the chincha were 19 mm at the wings 17 mm at the cod mouth 16 mm at the cod sleeve and 10 mm at the cod-end piece. Abiotic parameters (temperature and dissolved oxygen) were recorded with an oxygen meter (CONSORT Z621) salinity was recorded with a refractometer (ATAGO) and water transparency was estimated based on turbidity and Secchi depth according to Yanez-Arancibia et al. 1983 (in Rebelo 1992). Fishes were preserved by freezing. At the laboratory each specimen was identified according to the taxonomic keys of Bauchot and Pras (1987) and Whitehead et al. (1986) measured (total length) and weighed (total weight). The abundance biomass and species richness of the ichthyofauna were determined by sampling station. Fish were sampled monthly between November 1998 and November 2000 with a chincha a traditional beach-seine net. At each site and month three replicate samples were taken at low tide during the 5 days of the new moon at adjacent non-overlapping areas at nine sites. These sites strategically covered all the lagoon area and are designated as BAR GAF and SJA (near the mouth of the lagoon) ARE CAR and VAG (at the edges of the main channels) RIO (in the main freshwater area highly organically enriched) LAR (in the area showing the highest levels of industrial pollution) and TOR (approximately in the middle of the longest channel) (Fig. 1). The chincha gear used was almost rectangular in shape and composed by a central bag (a cod-end 295 cm of length and 145 cm of wide) two lateral wings (12 m of length each the width decreasing along the net reaching 50 cm at the edge and a central height of 1.5 m) two ropes (6.1 m each) and ?oating buoys at the top and ceramic weights at the bottom of the net. The end of the net was ?xed to the margin and the remainder was trawled in a semi-circle thus retaining within the cod-end all the ?sh from the area. The total area enclosed by the gear was estimated calculating the area of the semicircle of the lateral wings (93.6 m2) plus the area of the semi-circle of the cod-end (5.6 m2) plus the area of the rectangle formed by the two ropes (94.2 m2). The area of the whole net was approximately 193 m2 in each trawl. The net ef?ciency is estimated at 90percent based on continued observations of ?sh escaping above or behind the net. Fishes were preserved by freezing and they were identi?ed using taxonomic keys of Whitehead et al. (1986) and Bauchot and Pras (1987). The number of all specimens was recorded and the total length (accuracy 0.01 cm below) and biomass (wet weight accuracy 0.1 g) of ?sh were determined. The abundance biomass and species richness of the ichthyofauna were determined by sampling station. Fish were sampled monthly between November 1998 and November 2000 with a chincha a traditional beach-seine net. At each site and month three replicate samples were taken at low tide during the 5 days of the new moon at adjacent non-overlapping areas at nine sites. These sites strategically covered all the lagoon area and are designated as BAR GAF and SJA (near the mouth of the lagoon) ARE CAR and VAG (at the edges of the main channels) RIO (in the main freshwater area highly organically enriched) LAR (in the area showing the highest levels of industrial pollution) and TOR (approximately in the middle of the longest channel) (Fig. 1). The chincha gear used was almost rectangular in shape and composed by a central bag (a cod-end 295 cm of length and 145 cm of wide) two lateral wings (12 m of length each the width decreasing along the net reaching 50 cm at the edge and a central height of 1.5 m) two ropes (6.1 m each) and ?oating buoys at the top and ceramic weights at the bottom of the net. The end of the net was ?xed to the margin and the remainder was trawled in a semi-circle thus retaining within the cod-end all the ?sh from the area. The total area enclosed by the gear was estimated calculating the area of the semicircle of the lateral wings (93.6 m2) plus the area of the semi-circle of the cod-end (5.6 m2) plus the area of the rectangle formed by the two ropes (94.2 m2). The area of the whole net was approximately 193 m2 in each trawl. The net ef?ciency is estimated at 90percent based on continued observations of ?sh escaping above or behind the net. Fishes were preserved by freezing and they were identi?ed using taxonomic keys of Whitehead et al. (1986) and Bauchot and Pras (1987). The number of all specimens was recorded and the total length (accuracy 0.01 cm below) and biomass (wet weight accuracy 0.1 g) of ?sh were determined. The abundance biomass and species richness of the ichthyofauna were determined by sampling station. Unit of abundance = IndCountInt, Unit of biomass = Weight