This repository contains abiotic data and abundance/biomass data on zooplankton collected in the Elbe estuary. 

Title: Spatial and temporal succession of zooplankton in a temperate mesotidal estuary under anthropogenic pressure

Estuarine zooplankton are vital primary consumers and essential for estuarine ecosystem functioning and productivity, but they face strong physico-biochemical gradients as well as often anthropogenically altered habitats that impact their spatial and temporal dynamics. Detailed zooplankton community studies are scarce and outdated for the turbid and dredged Elbe estuary in northern Germany. We provide a comprehensive overview of micro-, meso- and macrozooplankton dynamics in the Elbe estuary by examining their spatio-temporal succession relative to environmental factors. Using redundancy analyses, we analyzed zooplankton assemblages and abiotic conditions at six stations along a salinity gradient during seasonal sampling in 2021 and 2022. Salinity and chlorophyll a emerged as key factors influencing spatial species distribution. An autotrophic zone with high chlorophyll a levels and low turbidity was confined to a shallow freshwater zone upstream of the dredged Hamburg Harbor region, supporting a community dominated by typical freshwater cyclopoid and calanoid copepods, cladocerans and rotifers, peaking in spring and summer. Eurytemora affinis was the most abundant copepod year-round throughout the entire estuary, exhibiting a marked tolerance to high turbidity. Coastal taxa such as Acartia spp., Paracalanus parvus, and Mesopodopsis slabberi colonized only the lower estuarine zone due to their affinity for high salinities. Compared to earlier studies, overall zooplankton abundance has declined, potentially in response to climatic changes and environmental alterations from recent hydromorphological interventions. This study enhances our understanding of the environmental drivers shaping estuarine zooplankton dynamics, which is essential for their conservation in the face of global change.