water Article Trophic Magnification of Legacy (PCB, DDT and Hg) and Emerging Pollutants (PFAS) in the Fish Community of a Small Protected Southern Alpine Lake (Lake Mergozzo, Northern Italy) Michela Mazzoni 1,2,*, Claudia Ferrario 2, Roberta Bettinetti 1 , Roberta Piscia 3 , Davide Cicala 3, Pietro Volta 3 , Katrine Borgå 4, Sara Valsecchi 2 and Stefano Polesello 2,* 1 Department of Human Sciences and Innovation for the Territory (DISUIT), University of Insubria, Via S. Abbondio 12, 22100 Como (CO), Italy;
[email protected] 2 Water Research Institute (IRSA)—CNR, Via del Mulino 19, 20861 Brugherio (MB), Italy;
[email protected] (C.F.);
[email protected] (S.V.) 3 Water Research Institute (IRSA)—CNR, Largo Tonolli 50, 28922 Verbania Pallanza (VB), Italy;
[email protected] (R.P.);
[email protected] (D.C.);
[email protected] (P.V.) 4 Department of Biosciences, University of Oslo, P.O. Box 1066, 0316 Oslo, Norway;
[email protected] * Correspondence:
[email protected] (M.M.);
[email protected] (S.P.) Received: 22 April 2020; Accepted: 2 June 2020; Published: 3 June 2020 Abstract: The biomagnification of mercury, polychlorobiphenyls (PCBs), dichlorodiphenyltrichl oroethane and its metabolites (DDTs) and perfluoroalkyl acids substances (PFASs) was evaluated in the trophic web of Lake Mergozzo, a small and deep Italian subalpine lake, which has been chosen because it is a protected environment, and discharges into the lake are mostly avoided. Carbon source and relative trophic levels were calculated by using 13C and 15N stable isotopes, respectively, and trophic magnification factors (TMFs) were derived.