DEVELOPMENT OF A BIOTIC INDEX FOR VOLUNTEER MONITORING AND ASSESSMENT OF STREAM WATER QUALITY

Abstract

The implementation of a water quality assessment and monitoring program is paramount to an efficient system of water regulation and management. These activities are, or should be, performed by official environmental protection agencies, but two major drawbacks hinder such actions: analytical methods used are often inappropriate to evaluate ecosystem health and the incapacity to attend the overwhelming growing demand. To solve these problems, Brazilian “Water Legislation” stimulates public participation in the management of water resources. As a contribution to this process, this study aims to develop a biotic index for volunteer monitoring and assessment of wadeable streams. The index (IBVol) is composed by tolerance values, which were attributed to macroinvertebrate groups based on their distribution in an anthropogenic impact gradient represented by 52 sites/occasions. The IBVol was correlated to environmental parameters as well as to Biochemical Oxygen Demand, indicating its ability to reflect both major ecosystem changes and the water quality. A test performed in Espirito Santo State indicated the index is robust enough to be used in other regions, in streams with similar ecological conditions to those where it was created. As a future perspective, the IBVol should be tested in volunteer monitoring programs.