Survey of biological resources to support environmental sensitivity- Maps: Case study on mangrove areas of a subtropical Brazilian estuary

Abstract

Maps of environmental sensitivity to oil (ESI maps) are used as primary source of information in response to oil spills, showing the sensitivity of environments and priority areas for protection. The sensitive areas are determined by shoreline classification (environmental sensitivity index) that follows a 1 to 10 scale which classifies coastal environments using their physical characteristics (slope, wave exposure, grain size). Although the biological resources are the most important information contained in ESI maps, these resources are not used to define the sensitivity index and are represented through specific icons. In this work, information of biological resources obtained from the literature review were used to determine more sensitive areas in environments classified with the same index of sensibility (mangroves - ESI 10). The study area is the Santos - Sao Vicente Estuarine System, located on the central coast of Sao Paulo State. Brazil. This region is composed of wide mangrove areas; some of them impacted by the Port of Santos and threatened by oil spills. Information of biological resources obtained from the literature was inserted in GIS program, showing the distribution of the different species along the study area, which allowed visualizing richer and more diverse areas within the study area. Thus, the analysis of the generated maps allowed the identification of priority areas for protection within an environment with the same sensitivity index. The maps presented in this work showed the importance of properly diagnosing the biological resources to define priority areas that should be protected from oil spills, since even in maximum sensibility levels, as mangroves, we could find more sensitive areas according to the presence of biological resources.