10 sites covering the estuarine coastal lagoon Ria de Aveiro (northwestern coast of Portugal)

Dissolved oxygen parameters in the water column; Fish morphology, age and physiology; Fish abundance in water bodies; Fish taxonomy-related abundance per unit area of the bed; Fish taxonomy-related ash-free dry weight biomass per unit area of the bed; Fish taxonomy-related counts; Salinity of the water column; Secchi disk depth; Temperature of the water column; Alkalinity, acidity and pH of the water column

Pelagic trawl nets; salinity sensor; pH sensors; dissolved gas sensors

The abiotic hydrological environment and the community dynamics of the fish fauna were investigated in the Ria de Aveiro, an estuarine coastal lagoon system, of area 43 square kilometres which has both marine and fluvial influences. Abiotic hydrological and fish community parameters were recorded routinely during 12 months at 10 stations. Temperature ranged between 9.5° C and 26.0° C, salinity between 0.0 o/oo and 32.0 o/oo, dissolved oxygen between 0.8 mg/l and 15.4 mg/l, pH between 6.1 and 9.4, and transparency between 4.4 per cent and 100 percent. No significant differences were observed in temperature and dissolved oxygen, among stations, or in seasonal variation in transparency. A total of 19,031 fish specimens from 55 species were sampled. Abundance, biomass and species richness were highest in summer and late winter at stations near the lagoon entrance. Sedentary species were most numerous, marine migratory species had the highest biomass and the category 'occasional species' had the highest number of species. Atherinidae, Mugilidae and Gobiidae were the most important families. Eight species represented about 80 per cent of the total fish abundance and biomass but only six species occurred in all the months and at all the stations. It was concluded that the Ria de Aveiro, with high seasonal and spatial abiotic variation, has a very rich and representative fish community compared with temperate and tropical estuaries and estuarine coastal lagoons around the world.

Anon (1988) Contribuicao para um levantamento demografico da ictiofauna da Ria de Aveiro, p. 228-239: in La Conferencia Nacional sobre a Qualidade do Meio Ambiente, Vol. I. Universidade de Aveiro, Aveiro (Portugal)., C. Borrego, I. Fernandes, A.P. Rosa Pires, and Samagaio, A.; Rebelo, J.E. (1992) The Ichthyofauna and Abiotic Hydrological Environment of the Ria de Aveiro, Portugal. Estuaries 15 (3): 403-413.,

University of Aveiro, Department of Biology
Campus de Santiago
Aveiro
Aveiro
3810-193
Portugal