Spatial and temporal organization of a coastal lagoon fish community – Ria de Aveiro, Portugal

Pombo L., Rebelo J.E.

Date de parution: septembre 2002
Volume: 26
Number: 3
Pagination: 185-196
Editeur: Société Française d’Ichtyologie
doi: https://doi.org/10.26028/cybium/2002-263-004
Résumé

The fish community and its spatial and temporal organization were studied in the Ria de Aveiro. This lagoon system (43 km2 in area), has both marine and fluvial influences and is located between 40º30’ - 40º52’N and 8º35’ - 8º47’W on the central coast of Portugal. The ichthyofauna was sampled monthly, from December 1996 to November 1997, at nine selected stations, with “chincha”, a traditionally-used beach-seine-type net of the region. A total of 14,598 specimens representing 43 species from 21 families were caught. The abiotic parameters (temperature, salinity and dissolved oxygen) showed significant seasonal variations, although only salinity and transparency showed statistically significant trends among sampling stations. The diversity and evenness were greater at the borders of the lagoon. The species richness, diversity and evenness peaked in mid-Summer. Marine seasonal migrant species were the most numerous, and the marine juvenile and estuarine resident categories had the highest number of species. Species number and diversity of the ecological guilds showed some spatio-temporal patterns due to some particular dominant species. Mugilidae, Atherinidae, Moronidae and Clupeidae were the most abundant families. Six species were dominant and represented more than 74% of the total fish abundance, although they did not occur over the whole lagoon area or during the whole sampling period. The study concludes that the fish community of the Ria de Aveiro has well-defined seasonal and spatial patterns.

Mots-clés: Diversity - Ecological guilds - Evenness - Ichthyofauna - Lagoon - Portugal
PDF visible pour tous