Background Contribution to Assess the Trophic Water Conditions and Organic Components in Sediments at Santos and Cananeia Estuarine Systems-Brazil

The dissolved inorganic compounds are normally used to identify the water quality of the coastal ecosystems. In the last decades, the dissolved organic compounds acquired a new dimension, in the water and in the sediments, due to its important role in the biogeochemical cycle of the organic matter. Concerning it, proteins, carbohydrates and lipids present on the sediments could be used in order to access the environmental trophic state. In this study, water properties and organic matter compounds in sediments were used in order to verify the trophic condition once it is a rare data from these regions. Although the PCA groupings are based on specific variables, such as water and sediment parameters, two specific groups were observed in both cases (a and b). Group a suggests stations with eutrophication tendency or, based on sediment variables, in hypertrophic condition, while Group b suggests areas in healthier conditions as meso-oligotrophic environments. Similarities on grouping based on water and sediment parameters were observed. The study of coupling water and sediment properties (pelagic and benthic coupling) and organic compounds constitute an important focus for improving the access to the trophic state avoiding the evaluation based only on sediment parameters that could cause more incertitude.