## 1 Introduction
In Europe, the environmental status of water compartments (including neritic areas) is regulated by the 2013/39/EU directive [22], adopted in Italy by the Legislative Decree 172/2015 [23], in which a list of priority substances (including selected PAHs and PCBs compounds) to be monitored in water, sediments and biota is reported. For individual congeners of PAHs, Environmental Quality Standards (EQS) are fixed for water, sediments and biota, defining annual average values (AA-EQS) and maximum allowable concentrations (MAC-EQS). Conversely, AA-EQS for PCBs in biota refer only to dioxin-like congeners, while with regards to sediments the same dioxin-like compounds, together with other eight congeners, are considered. It should be highlighted that, to date, the limits for PCBs in marine waters remain unregulated. Due to the strategic importance of coastal areas in the marine ecosystems, as previously presented, several studies investigated the contamination from PAHs and PCBs in neritic environments, as well as their partition between water columns, sediments and biota [24; 25; 26]. Within this literature, an extensive bibliography is dedicated to the Mediterranean Sea which, due to its morphological peculiarities, is strongly subjected to anthropic impact. In particular, studies on PAH and PCB contamination of the Venice Lagoon [27], Tyrrhenian Sea [28], and Ionian Sea [29] are reported. On the other hand, few studieswere focused on Ligurian Sea [30; 31; 32], even though its pollution causes serious concern, due to intense anthropic activities (e.g., ports, industries, tourism, etc.) [32]. Furthermore, studies investigating the possible distribution pathways of PAHs and PCBs within neritiic compartments of Ligurian Sea are, as far as we know, absent thus far, despite the natural (marine protected area) and economic (shipping, industries, harbors) strategical importance of this area. Based on the above considerations, the aim of this work is the study of the contamination of PAHs and PCBs (both dioxin and non-dioxin-like congeners) in the neriti environment of the Southern Ligurian Sea, which hosts a protected marine area called \"Cetacean Sanctuary\". The study focuses comprehensively on the possible partition of micropollutants among the environmental compartments of the marine ecosystem (seawater, sediment and zooplankton), and on the factors that could influences these transfer behaviors (i.e., seasonality). With this aim, analytical protocols for the extraction and quantitation of PAHs and PCBs from seawater, sediment and zooplankton were developed and validated. Furthermore, to better understand the presence of preferential pathways of bioaccumulation in zooplankton, partition studies were also carried out in four taxa, chosen on the basis of dietary habits (herbivorous or carnivorous) and living environment: hyperbenthic Isopoda, herbivores and carnivorous holoplankton crustacean copepods and fish larvae (ichthyoplankton). To the best of our knowledge, this study is the first to describe the partition of PAHs and PCBs in this protected area of the Ligurian Sea, with unique natural characteristics, providing insights on the contamination of the whole bioma.