Integrated assessment of the surface water quality: trophic state and protection of aquatic life in the Anil and Bacanga rivers, Sao Luis (MA)

This work proposes two indexes to assess the quality of surface waters where domestic sewage or similar pollution source prevails: the Trophic State Index (IETP) and the index for protection of aquatic life (IQA(pva)). Both were applied to Anil and Bacanga rivers located on Maranhao Island. Although the general quality of the water indicates human presence, the Anil River stands out by its high trophic level and poor conditions for aquatic life. The results of applying these indexes allow easily assess of the degradation state of the ecosystem. By being connected directly to basic sanitation, these indices are an important management tool for governmental and non-governmental stakeholders.