Subtidal macrobenthic structure in the lower Lima estuary, NW of Iberian Peninsula

Seasonal variation of the subtidal macrobenthic community in the lower Lima estuary was investigated at twelve sites. Univariate and multivariate analyses were used to establish patterns in species distribution, abundance, and biomass; and to determine the influence of site and season on the subtidal macrobenthic community. A total of 101 macrobenthic taxa were identified and values of diversity were generally low indicating a high degree of dominance of few species. Average abundance and biomass per site ranged from 46.7 to 8060 ind. m -2 and 0.56 to 28.96 g AFDW m -2 , respectively. Abra alba was most abundant and had the highest biomass. Multivariate analysis revealed four distinct groups. Each group was represented by a specific species composition and characterised by different environmental conditions, in particular, the sediment characteristics and salinity. Abundance/biomass comparison (ABC) indicated that the lower part of the estuary is under environmental stress and is dominated by opportunistic species. The subtidal macrobenthic community of the lower Lima estuary differed between sites but not between seasons of the year.