Biogeochemical Characteristics in the Saronikos Gulf (Aegean Sea, Eastern Mediterranean)

Abstract

AbstractThe Saronikos Gulf and the small emBayment of Elefsis Bay (Eastern Mediterranean, Greece) represent the seaward boundary of the metropolitan areas of Athens and Piraeus Port, hosting 1/3 of the current Greek population. It constitutes a complex ecosystem due to the topographical and hydrological differentiation of the area, as well as its trophic character. Maintenance of the good environmental status of the Saronikos Gulf marine ecosystem is very important due to the cumulating impacts coming from multiple human activities. In order to protect and improve the marine environment and implement effective policies to sustain its quality, it is necessary to monitor the spatial and temporal variation of the major ecosystem elements, the pollutant levels, and their effects on the ecosystem and marine organisms. Thus, in this chapter, we provide an overview of ecosystem elements, hazardous substances, and alien species that have undergone changes over the last 25 years because of the various pressures, emphasizing mainly the sewage treatment plant of Athens in Psittalia Island. The environmental status of the inner Saronikos Gulf is also examined.Summarizing, we highlight the gradual improvement of many parameters of the ecosystem. This trend of improvement has started since 2004, as a result of the secondary treatment of the wastewater and the decrease of the industrial activities following the economic crisis in Greece. Nevertheless, it is essential the maintenance of the monitoring of the Saronikos Gulf and Elefsis Bay in order to investigate any expected change due to cumulative impacts from multiple human activities which in combination with climate change may provoke new ecological balances. Possible changes and impacts on the Saronikos Gulf ecosystem must be recorded to optimize the protection and the management of the marine environment in the context of the implementation of the European Directives in our country.KeywordsAegean SeaBiodiversityEcological qualityEcosystem elementsHazard substancesInterannual variabilitySaronikos Gulf