Responses of Zooplankton Community Pattern to Environmental Factors along the Salinity Gradient in a Seagoing River in Tianjin, China

Abstract

As the primary consumers in aquatic organisms, zooplankton play an important role in aquatic ecosystems. It is valuable for management and researchers to have an insight into the responses of zooplankton community patterns to environmental factors. In this study, RDA and variation partitioning analysis were adopted to determine the important environmental factors affecting zooplankton abundance and biomass, as well as the relative importance of different environmental factors. The findings reveal that TN (total nitrogen), WD (water depth), pH, and SAL (salinity) were all important abiotic factors shaping the zooplankton community pattern in the study area. TN affected protozoa by influencing Stentor amethystinus, while the effects of WD on copepods may have been mainly induced by the responses of Calanus sinicus and Paracyclopina nana. By inhibiting Stentor amethystinus and Vorticella lutea, pH significantly affected protozoa. In addition, Rotifera and copepods were affected by SAL mainly through the responses of Brachionus calyciflorus, Calanus sinicus, and Ectocyclops phaleratus. Importantly, fundamental alternations in the variation trends of zooplankton abundance and biomass along the salinity gradient were found when the salinity was approximately 4–5. By combining these results with the findings on phytoplankton responses to salinity in previous studies, it can be concluded that salinity may influence the river ecosystem by influencing zooplankton abundance and biomass rather than phytoplankton.

Modeling Dynamic Processes in the Black Sea Pelagic Habitat—Causal Connections between Abiotic and Biotic Factors in Two Climate Change Scenarios

“…The local community structure is shaped by local environmental parameters, such as water temperature, pH, salinity, trophic state, or combinations of these factors (i.e., the speciessorting hypothesis) [61]. Furthermore, environmental nutrients significantly influence zooplankton [62,63], indirectly impacting zooplankton by having a top-down effect on phytoplankton [64].…”

“…Temperature influences zooplankton metabolism and phytoplankton photosynthesis rates, impacting their growth and reproduction [67]. Salinity variations affect zooplankton distribution and phytoplankton osmoregulation, influencing community composition and species abundance [64,68]. Nutrient availability directly influences phytoplankton growth and zooplankton populations through food availability.…”

Modelling Dynamic Processes in the Black Sea Pelagic Habitat -Casual Connections between Abiotic and Biotic Factors in Two Climate Change Scenarios

“…The local community structure is shaped by local environmental parameters, such as water temperature, pH, salinity, trophic state, or combinations of these factors (i.e., the species-sorting hypothesis) [30]. Furthermore, zooplankton is significantly influenced by nutrients in the environment [31,32], having an indirect impact on zooplankton by having a top-down effect on phytoplankton [33].…”

Relationship between the carbonate system and phytoplankton community in the Gulf of Guinea-Africa

“…The Dinophyta unlike the Bacillariophyta, are more oceanic than coastal. A very low representation of microalgae belonging to the Chlorophyta group may be associated with their ecological need because the only one species of this group is a freshwater species, reflecting low salinity condition (Sun et al, 2023). One species of group Dictyochophyta and the species of Chlorophyta were the first Monthly density of different phytoplankton groups (Cell L -1 ) from April 2020 to December 2020. species encountered in Ivorian oceanic waters.…”