# DPSIR Model Applied to the Remediation of Contaminated Sites. A Case Study: Mar Piccolo of Taranto
## 7 Impacts
### Effects of Contaminants in Marine Organisms  
[PERSON] and [PERSON] [64] evaluated the degree of pathogenic microbial pollution, vibrios, fecal coliforms, and Escherichia coli densities in mussels (_Mytitlus galloprovincialis_) collected in 30 sampling sites in the Mar Piccolo. _Vibrio oligolyticus_ appeared as the predominant component of the total culturable vibrios. Some Vibrio species, such as _V. mediterranei, V. parahaemolyticus, V. diazotrophicus, V. nereis, and V. splendidus,_ were present both in water and in mussel samples; however, other vibrios were found in mussels (_V. vulnificus, V. cincinnatiensis, V. orientalis, V. anguillarum, V. marinus, V. lollisea_). As this research suggested, it is fundamental to isolate potential pathogenic vibrio species to avoid the transmission of infection to man and other marine organisms. Bioaccumulation data showed severe results. [PERSON] et al. [65] and [PERSON] et al. [66] presented spatial and seasonal variations data on the PCDD/Fs and DL-PCBs in mussels of Mar Piccolo. The main results indicated that PCDD/Fs and DL-PCBs contamination in mussels was higher in the First Bay, with DL-PCBs as the dominant chemicals in all samples, followed by PCDFs and PCDDs. Another finding showed a relevant increase in dioxin and dioxin-like PCB TEQs during the summer. Two peaks were reached in June (\(8\pm 2\) pgTEQ/g ww) and in July (\(11\pm 3\) pgTEQ/g ww), above the legislation limit of \(6.5\,\mathrm{pg}\,\mathrm{WHO}_{2005}\)-TEQ g\({}^{-1}\) ww. Nevertheless, the exceeding limits in the first inlet, set by the EC Regulation, have involved the prohibition of mussel sale and commercialization from this basin. Concerning the bio-accumulation of metals, [PERSON] et al. [67] analyzed samples of _Mytitlus galloprovincialis_ collected monthly, determining, by atomic absorption spectrophotometry (AAS), the metals (Cd, Cu, Pb, Zn, Fe and As) in the whole soft tissue of mussels. Even in this case, seasonal changes in metal concentrations were observed, exhibiting maximum values in later winter to early spring, followed by a progressive decrease during the summer. Their research indicated that the metal content was within the permissible range established for safe consumption by humans. All the above observations raise several questions about the potential mobility of pollutants and their risks for the surrounding environment. The Italian national research group of Taranto carried out bioaccumulation tests to investigate the potential gathering of pollutants by mussels. Experiments were developed both ex situ (in a laboratory) and in situ (in a station in the Arsenal area in the First Bay). For bioaccumulation tests, clean _Mytitlus galloprovincialis_ were used. Ex situ tests were conducted in laboratory in a fish tank filled with 280 L of marine water and 30 kg of marine sediments collected from the same station used in the in situ tests. Figure S5 in the Supplementary Material shows how mussels were suspended on a grid during the testing period. Every 7 days, a resuspension event was induced and at days 1, 15, 30, and 45, a defined quantity of mussels was collected. A similar approach was taken for the in situ experiments. At the test station, mussels were collected at the same periods and resuspension events were induced every 7 days through the help of divers  
Figure 14: Results of the speciation analyses in Stations 1 and 2 (by using the Tessier approach). Tables 4 and 5 shows the percentage increase in metals in mussels at T15, T30, and T45 days in reference to T0 in both ex situ and in situ experiments. The highest percentage increase is given by mercury, especially ex situ with 1350%. A study by [PERSON] and [PERSON] (1986) identified the principal mercury source for bivalves in contaminated sediments. However, all metals showed an increase in both ex situ and in situ samples during the investigation period. Concerning PCBs, an increase of 56% was the highest value recorded, exceeding the threshold limit (Regulation CE no.