Mapping the anthropogenic impact in the Taranto coastal area (southern Italy) through a multidisciplinary methodological approach

This study is aimed at defining the environmental status of the Mar Piccolo and Mar Grande basins, in the Taranto coastal area (Ionian Sea, Taranto Gulf, southern Italy), through the application of a multidisciplinary approach. The investigated coastal system was affected by intensive environmental changes due to the strong industrialization that has taken place since the second half of the XIX century. In addition, the area is characterized by intense human pressure (in terms of high-density urbanization and the presence of military harbor activities, industries, and aquaculture plants), which contributes to its environmental degradation. The area of Taranto is nowadays one of the most polluted sites in Italy and for this reason, it is included in the perimeter of the Site of National Interest “Taranto” (established by the National Law 426/1998 and delimited by the Ministerial Decree of 10/01/2000) for which urgent environmental remediation is required.

The study is based on the integration of geophysical and chemical data acquired in the framework of the interdisciplinary activities funded by the “Special Commissioner for urgent measures of reclamation, environmental improvements, and redevelopment of Taranto” in 2015 and 2017.

In this research, we proposed a methodological approach for the assessment of the spatial distribution of direct and indirect anthropogenic impact on the sea-floor, in terms of both presence of macro-litter (elements and/or traces) and chemical pollutants. Specifically, the results derived from the interpretation of the acoustic data (multibeam echosounder - MBES and Side Scan Sonar - SSS) acquired in both basins and chemical analysis, with particular reference to inorganic compounds, performed on the sediment samples of 19 continuous cores collected in the Mar Piccolo, were combined. Following the analytical procedure proposed in previous studies, seafloor morphologies were detected by interpreting the digital elevation model obtained by MBES and integrated by the interpretations of the SSS backscatter mosaic data while the distribution of toxic heavy metals in marine sediments has been explored by using different pollution indicators, generally considered as a useful tool for evaluating the degree of anthropogenic contamination.

The integrated results obtained by the multiproxy analysis have allowed us to define the overall distribution of the anthropogenic impact along the Mar Piccolo and Mar Grande basins and to identify hotspot areas for which urgent remediation and management actions should be implemented.