Desenvolvimento de um índice de integridade biológica baseado em peixes para áreas úmidas

Abstract

Wetlands are ecosystems of great ecological, economic and cultural importance. Currently there are less than half of the ones that existed a century ago. This loss is caused by human activities, such as agricultural expansion and increasing urbanization. Moreover, these factors are causing the high level of degradation of the remaining areas of these environments. Due to the presented problem it is necessary to manage the wetlands, to detects of environmental impacts and characterize biologically. The approach called biological monitoring is based on the response of organisms in relation to the environment in which they live. Fish were successfully used as environmental quality indicators and present numerous advantages as indicator organisms for environmental monitoring, as they occur in almost all aquatic environments. They are relatively easy to identify and sensitive to environmental changes. The use of biological indicators to detect the degradation of wetlands, along with the continue use of this approach to assess the quality of the environment, led to the development of a Index of Biological Integrity (IBI) for wetlands that could be used to classify degradation level. This index was first developed Karr, in 1981, showing a multimetric procedure to monitor water resources using the ichthyic fauna. The inclusion of IBI in monitoring programs can be used to detect spatial and temporal trends of water quality, being an effective tool in the conservation and management programs for aquatic ecosystems also in Brazil. In this sense, the specific objectives of the study are to verify the richness, abundance and diversity of fish in wetlands of Rio dos Sinos basin that suffer different human pressures, classify the land use in the vicinity of sampling areas, check the potential of fish community as biomonitoring tool of water quality in wetlands, evaluate the influence of the rural and urban areas on wetlands, identify qualitative and quantitative metrics based on the fish community to aggregate information available about different aspects of wetlands and finally develop na index of biological integrity.