Comparison of the fish assemblages in tidal salt marsh creeks and in adjoining mudflat areas in the Tejo estuary (Portugal)

摘要

A comparative analysis of the fish assemblages in two tidal salt marsh creeks and in the adjoining mudflat areas was conducted, based on two years of sampling surveys performed in different years, using a fyke net and a beam trawl, respectively. Fish species richness was higher in the mudflat areas (27 species) than in the tidal creeks (14 species). Liza ramada and Pomatoschistus microps were the most abundant species in tidal creeks, while the adjoining tidal flats were dominated by P. microps and Pomatoschistus minutus. The seasonal pattern of variation was different in the two habitat types. The main differences observed were mainly related with peak abundance of resident species and periods of estuarine colonization by juveniles of marine species that used the estuary as nursery area. The results obtained emphasize the importance of intertidal creek habitat within the estuarine environment for some fish species, particularly as juveniles. The utilization of this habitat is mainly related with feeding and predation avoidance.