Baseline studies constitute, at the same time, the base and the reference point for the development of site-specific monitoring programs. As a previous step in the analysis of the structure of benthic communities in the infralitoral off Avilés and Gijón, multivariate techniques were used to assess the agreement between the distribution pattern of samples, from both rocky and soft bottom benthos, according to their species or family compositions.

Sampling was carried out in summer 1992. Stations were located on a depth gradient basis (A: −1 m; B: −5 m; C: −15 m; D: −25 m; E: −35 m; F: −45 m) along eight transect lines. Abundance data from replicate samples from each station, aggregated at both the species and the family levels, were tested by three complementary multivariate measures of community structure: clustering (CL), principal components analyses (PCA) and multidimensional scaling (MDS) techniques.

The main results obtained in this study demonstrated the adequacy of family-based abundance data for carrying out classification and ordination of samples from both rocky and soft bottom benthic ecosystems.