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

Title: Spatial and Temporal Succession of Zooplankton in the Dredged Elbe Estuary (Northern Germany)

Estuarine zooplankton play a crucial role as primary and secondary consumers in estuarine pelagic food webs. They are exposed to strong fluctuations in physico-biochemical conditions and human stressors, such as dredging and intense agricultural land use, which affect the population dynamics on spatial and temporal scales. However, detailed community studies under certain estuarine conditions are rare and outdated for the highly turbid and dredged Elbe estuary (Germany). We provide a comprehensive overview of the micro- meso- and macrozooplankton population dynamics in the Elbe estuary by examining their spatio-temporal succession in relation to physical and biochemical gradients. For this, we applied a redundancy analysis on zooplankton assemblages of the three size groups and environmental data (chlorophyll a (Chl a), suspended particulate matter (SPM), dissolved nutrients, temperature, salinity, oxygen, pH) that were collected at six stations along the entire salinity gradient during seasonal sampling campaigns in 2021 and 2022. Salinity and Chl a were the primary factors affecting the spatial distribution of zooplankton, with highest Chl a concentrations restricted to the non-dredged section, where SPM levels were lowest. This autotrophic zone was favourable for a distinct freshwater assemblage consisting of cyclopoid and calanoid copepods (e.g. Eurytemora affinis) and cladocerans (e.g. Bosmina longirostris), and rotifers (e.g. Keratella spp., Brachionus spp.), with abundances peaking at high Chl a concentrations, particularly in spring and summer. E. affinis emerged as the most abundant copepod throughout the entire estuary, exhibiting a marked tolerance to high SPM loads. Euryhaline species, such as Acartia spp., Paracalanus parvus and Mesopodopsis slabberi colonised the lower part of the estuary with higher salinities. This study enhances our understanding of estuarine zooplankton population dynamics under various environmental conditions, which is essential for preserving these systems in the face of global change.