Dataset of Contamination (2009–2022) Legacy Contaminants (PCB and DDT) in Zooplankton of Lake Maggiore (CIPAIS, International Commission for the Protection of Italian-Swiss Waters)

Lake Maggiore, located in the subalpine region between Italy and Switzerland (80% and 20% of the surface area), is a deep (mean depth: 178.9 m; maximum depth: 370 m) and large (surface area: 213 km2) lake. The lake rarely undergoes complete vertical mixing; in fact, it is classified as holo-oligomictic [1,2,3]. Lake Maggiore has 33 tributaries and one outlet, the Ticino River. Presently it is oligotrophic, after a successful eutrophication reversal due to sewage treatment plants and use of phosphorus-free detergents. A monitoring program on POPs in fish and in sediment cores was started after the discovery of fresh DDT discharge into the lake. The program was later extended to include a wide range of POPs, not least the PCBs. These compounds were almost undetectable in the water column; hence, after some years of monitoring different components of the lake environment, zooplankton became one of the crucial biomonitoring tools able to rapidly incorporate and transfer contaminants through the food web [4,5,6,7].