DNA metabarcoding and morphological analysis - Assessment of zooplankton biodiversity in transitional waters

Zooplankton biodiversity assessment is a crucial element in monitoring marine ecosystem processes and community responses to environmental alterations. In order to evaluate the suitability of metabarcoding for zooplankton biodiversity assessment and biomonitoring as a fast and more cost-effective method, seasonal zooplankton sampling was carried out in the Venice Lagoon and the nearby coastal area (Northern Adriatic Sea). The molecular analysis showed higher taxa richness compared to the classical morphological method (224 vs. 88 taxa), discriminating better the meroplanktonic component, morphologically identified only up to order level. Both methods revealed a similar spatio-temporal distribution pattern and the sequence abundances and individual counts were significantly correlated for various taxonomic groups. These results indicate that DNA metabarcoding is an efficient tool for biodiversity assessments in ecosystems with high spatial and temporal variability, where high sampling effort is required as well as fast alert systems for non-native species (NIS).