Adriatic Sea pollution, especially considering Northern basin, is more marked along the Italian, Western coast than along the Eastern coast. Furthermore, a correct evaluation of environmental contamination level cannot avoid considering the main ecosystem dynamics of the basin. In fact, substances such as organic and not organic micro-polluting substance, once introduced into the sea, are not dissolved: they isolate and concentrate, in a different way according to their chemical physical features, in sediments and organisms, where through bio magnification processes and trophic chains, can achieve high concentrations up to several sizes bigger than the initial ones. From mi 70'snumber of project were carnied out and they provided the first data concerning the presence of heavy metals and chlorinated hydrocarbons in water, plankton, mussels, fish, sediments. By that time the Adriatic Sea could be valued as a relatively clean ecosystem, in spite of the presence of some polluting substances with high concentration in limited coastal areas. Also, along the Eastern coast, in contrast to open sea lower values, it were detected evident effects of chemical organic and not organic pollution only in limited zones with urban centers and natural half-closed zones featured by a poor water change. Urban and industrial developments contribute to high level pollution. Oil spills are another source of contamination that directly affect seawater quality and entire see life.