Response of benthic macroinvertebrate community descriptors to chemical pollution in the aquatic ecosystems of Fiume Grande and Punta della Contessa saltpans (Brindisi, Italy)

The anthropogenic activities that take place in an area are reflected in the quality of the waters in the water bodies into which the area drains; these water bodies thus represent natural tools for monitoring the state of health of the whole catchment area. The objective of this study is to evaluate the sensitivity of benthicmacroinvertebrate communities in aquatic ecosystems to perturbations linked to chemical pollution. To this end a study was conducted in the aquatic ecosystems located within the Site of National Interest of Brindisi, performing seasonal samplings in 9 field sites. The analysis of the benthic macroinvertebrate communities entailed taxonomic identification, determination of biomass and evaluation of the body condition of each individual sampled. Taxonomic and non-taxonomic community indices were derived, and their models of variation were described and compared on gradients of concentration of chemical contaminants in the area. The results indicate significant relations between the concentration of heavy metals and descriptors of the size spectra of benthic macroinvertebrates, suggesting that in aquatic ecosystems, descriptors linked to size can be a useful tool in support of bio-monitoring and assessment of ecological risk, considering their ease of application and sensitivity to perturbation pressures in an industrial area.