Zooplankton trajectory before, during and after a hydropower dam construction

Abstract

Aim Understanding the impact of anthropogenic activities is central for supporting management and conservation efforts. In aquatic ecosystems, the construction of dams for hydroelectric power plants is a major environmental change that turns the riverine ecosystem into a reservoir lake. Such environmental deep alteration causes profound impacts in biota. The goal of this study is to make a comprehensive description of zooplankton trajectory following the construction of a reservoir in the transition from the hotspot Cerrado to Amazon, Central Brazil. Methods We used data sampled before, during and after the formation of the reservoir lake in 10 sampling units each period. We evaluated compositional changes, shifts in spatial organization, and a variation in beta-diversity from before to after the dam constructions using a set of multivariate analyses. We evaluated effects for Rotifers, Copepods and Cladocerans separately. Results Compositional changes were evident for all zooplankton groups: Rotifers, Copepods and Cladocerans. Besides, spatial community organization was also affected but depending on the beta-diversity facet and data resolution – mainly turnover using abundance data, except for Copepods. Finally, an increase in nestedness occurred for all groups during the formation of the reservoir lake. Conclusions In summary, our study showed the deep impacts for zooplankton that the formation of a reservoir lake causes. We innovate by making a complete assessment, which indicate clearly the complexity of evidencing impacts in aquatic communities. We also suggest that long-term monitoring should continue in reservoirs for scientific purposes. The changes in biota also make clear that the construction of dams should be accompanied by preservation of other pristine riverine ecosystems.

Water Quality and Plankton Assessment of Eme River, Umuahia, Southeast Nigeria

“…Schmidt et al [18] described zooplankton as a key biological group that is very important to the functioning of the ecosystem. They respond strongly to environmental changes and are used to assess the conditions in aquatic ecosystems [18,19]. Temporal and spatial variations of physico-chemical environmental conditions often result in dramatic and rapid changes in zooplankton because of their short life span and fast regeneration [20].…”

“…Zooplankton are microscopic animals that are essential components of aquatic food webs; an important link in the conversion of energy from producers to consumers [16,17]. Schmidt et al [18] described zooplankton as a key biological group that is very important to the functioning of the ecosystem. They respond strongly to environmental changes and are used to assess the conditions in aquatic ecosystems [18,19].…”

Water quality and zooplankton community of the Eme River, Umuahia, Southeast Nigeria

“…One of the essential biological communities found in lotic freshwater ecosystems is zooplankton. Zooplankton is microscopic animals that serve as an important link in the conversion of energy from producers to consumers; playing an essential role in the aquatic food webs (Sharma et al, 2010;Schmidt et al, 2020). Zooplanktons are weak swimmers and usually drift along with the currents (Prygiel and Coste, 1993).…”

Effects of damming, seasonality and different environments on reservoir phytoplankton

“…Therefore, the damming of the river had a negative effect on the phytoplankton communities, reducing their richness and density during the postdam period of the Tocantins River. Previous studies in the same field have also shown that damming impacts phytoplankton and zooplankton communities (Lu et al 2020;Silva et al 2020;Schmidt et al 2020;Silva et al 2023).…”