Temporal and spatial variation of the algal community in a southern Mediterranean shallow system

The algal community of a shallow system located in Western Sicily (Mediterranean Sea) has been investigated over 1 year in eight ponds (fredde). The spatio-temporal variation in total algal coverage, species richness and coverage in relation to environmental variables has been analysed. The algal community was very species-poor. A total of 50 taxa, mainly detached algae, were identified. A dominance of filamentous and foliose taxa was observed. Significant spatio-temporal differences in total algal coverage, species richness and coverage between the ponds of group A and those of group B were found. The separation into groups A and B was made a priori on the basis of different levels of proximity to the sea and anthropogenic pressure. In particular, the algal assemblage of ponds of group B, closer to the sea and subjected to a lower anthropogenic pressure, showed a good structure and the highest species richness. The separation of the ponds was successively confirmed by PERMANOVA. This study confirmed the effectiveness of using species as descriptors of spatio-temporal responses of the algal community to environmental variations.