Geochemical and isotopic analyses on the Po delta water: insights to understand a complex riverine ecosystem

This contribution was preliminarily presented with an oral communication during the “Water Day 2015” conference organized in Rome the 20th of March 2015 by the Accademia Nazionale dei Lincei. It implements a recent paper that studied the Po river water from the Alpine springs toward the Adriatic Sea (Marchina et al. Environ Sci Pollut Res 22, 5184–5203, 2015), specifically focussing on its deltaic part. The new geochemical analyses are useful to evaluate the extent of salinization (due to mixing with sea-water) and to monitor the flux of nutrients that are conveyed by the river toward the coastal environment. The paper also contains oxygen/hydrogen water isotopes that represent a snapshot of the current climatic conditions to be compared with the literature data and with the future composition to set up a hydro-archive that should be updated to evaluate on-going climatic changes. Moreover, the paper reports preliminary nitrogen isotopes composition of Po river water that trace the impact of human activities, to be monitored in the future to understand possible on-going pollutions. We conclude that geochemical researches on Po river should consider with particular attention the delta because it is an extremely fragile ecosystem where biogeochemical variations are more relevant.