Pollution monitoring of Bagnoli Bay (Tyrrhenian Sea, Naples, Italy), a sedimentological, chemical and ecological approach

Many studies finalised to a reclamation project of the industrial area were carried out on the industrial site of Bagnoli (Naples). Among these studies, the sedimentological, chemical, and ecological characteristics of marine sediments were analysed. Seven short cores, located in the proximity of a steel plant, were analysed for grain-size, polychlorobiphenyls, polycyclic aromatic hydrocarbons and heavy metals. As well, benthic foraminiferal assemblages were investigated. Sediment pollution was mainly due to heavy metals; in particular, copper, mercury and cadmium showed a ‘spot’ (site-specific) distribution, while iron, lead, zinc and manganese showed a diffuse distribution, with a gradual decrease of concentration from coast to open sea. Heavy metals pollution seems to explain some of the variation in the foraminiferal abundance. The combined copper and iron contamination might be the cause for the complete absence of foraminifera in the four shallower cores. Moreover, the ratio between normal and deformed specimens of Miliolinella subrotunda and Elphidium advena could be indicative of heavy metal pollution. In particular, Miliolinella subrotunda could be a potential bioindicator for copper pollution, since the abundance of irregular specimens of this species could be related to copper concentrations.

Keywords:

• steel plant
• foraminifers
• heavy metals
• bioindicators

Acknowledgments

The authors thank Dr. S. Focardi for determination of PCBs, Dr. A. Schiavetti and R. Spaziani for trace metals analyses, Dr. S. Rossi and G. Ciuffa for PAHs determination. The authors are grateful to Dr. G. Cavarretta, Director of IGAG (CNR), for the use of SEM and to Mr. A. Mancini for the technical assistance in SEM photographs.