Carbon and nitrogen (δ13C, δ15N) isotope ratios of zooplankton in Lake Maggiore: a 13-year dataset

In this paper, we present measurements of δ13C, δ15N, C% and N% for 1,084 zooplankton samples (2,168 total isotope analyses). The analyses were performed on zooplankton taxa inhabiting Lake Maggiore (Italy), including developmental stages of copepods, as well as on pooled organisms belonging to three size-fractionated groups (≥80 µm, ≥450 µm and ≥850 µm). We also include 1,232 data on Standing Stock Density and Biomass (SSD and SSB) for the ≥450 µm and ≥850 µm size fractions, while data related to ≥80 µm samples were published previously. The ≥450 µm and ≥850 µm size fractions were chosen to select the organisms preyed by zooplanktivorous fish, whereas the fraction ≥80 µm was included to better understand trophic relationships within the pelagic zooplankton community. The dataset resulted from a monitoring program on pelagic zooplankton and persistent organic pollutants funded by the Commissione Internazionale per la Protezione delle Acque Italo-Svizzere (CIPAIS) conducted between 2010 and 2022. The data allow for investigations of trophic relationships within the zooplankton community and with respect to fish in the large, deep subalpine Lake Maggiore, providing a basis for modelling transfer of persistent organic pollutants through the pelagic food web.