Spatial heterogeneity and seasonal succession of phytoplankton along the longitudinal gradient in a eutrophic reservoir

Abstract

In order to evaluate the effects of contrasting hydrological scenarios on the spatial and temporal heterogeneity of phytoplankton in a reservoir, vertical chlorophyll and temperature profiles were measured and functional classification of phytoplankton was applied. From April to October 2007, at 1-2 week intervals, seasonal changes in various parameters were studied along the longitudinal axis of the canyon-shaped, eutrophic Ř ímov Reservoir (Czech Republic). At the river inflow, phytoplankton markedly differed from the rest of the reservoir, being dominated by functional groups D and J (pennate diatoms and chlorococcal algae) without a clear seasonal pattern. From April to mid-June, groups Y and P (large cryptophytes and colonial diatoms) prevailed in the whole reservoir. Phytoplankton spatial heterogeneity was the most apparent during the summer reflecting a pronounced gradient of environmental parameters from the river inflow to the dam (e.g., decreasing nutrients, increasing light availability, etc.). A dense cyanobacterial bloom (groups H1 and M) developed in the nutrient-rich transition zone, while functional Group N (desmids) dominated the phytoplankton at the same time at the dam area. In late summer, a sudden flood event considerably disrupted thermal stratification, altered nutrient and light availability, and later even resulted in cyanobacterial dominance in the whole reservoir. Additionally, our study emphasizes the importance of having an intensive phytoplankton monitoring program, which would allow for detecting severe consequences of sudden flood events on phytoplankton spatial and temporal heterogeneity, which significantly affect water quality at the dam area used for drinking water purposes.

Alga-Derived Substrates Select for Distinct Betaproteobacterial Lineages and Contribute to Niche Separation in Limnohabitans Strains

“…Notably, these algal species belong to different taxonomic groups and represent species typical of phytoplankton assemblages (26). Moreover, the algal species are frequently found in the Ř ímov reservoir (27), where the Limnohabitans strains originated. The significant increments in abundance of the Limnohabitans bacteria cocultured with the algae or their EPP, compared to the control treatments ( Fig.…”

Patterns of asynchrony for phytoplankton fluctuations from reservoir mainstream to a tributary bay in a giant dendritic reservoir (Three Gorges Reservoir, China)

“…Temporal fluctuations of phytoplankton have thus been regarded as one notable characteristic of the reservoir ecosystem. Although spatial heterogeneity and temporal fluctuation of phytoplankton have been emphasized in reservoir limnology, few attempts have been made to combine both aspects and analyze spatial divergence of phytoplankton fluctuations (Rychtecký and Znachor 2011).…”

Spatial and temporal characterization of the physicochemical parameters and phytoplankton assemblages in Dodurga Reservoir (Sinop, Turkey)

“…Borges et al (2008) stated that generally phytoplankton present a longitudinal distribution pattern with greater concentrations in the transition zone of reservoirs and the short retention time of reservoirs constituted the principal limiting factor to phytoplankton development. Rychtecký and Znachor (2011) reported that the transition zone is characterized by high phytoplankton biomass and production, decreasing flow velocity, and increased water residence time and light penetration. The maximum number of total organisms in the depth samples was observed in May 2011 at 2 m and then 4 m as a result the availability of light and nutrients, and temperature.…”

“…Nowadays, the relationship between water quality and phytoplankton or algal communities is determined by CCA in most studies (Ersanli and Gonulol, 2007;Borges et al, 2008;Çelik and Ongun, 2008;Rychtecký and Znachor, 2011;Tezel Ersanli and Hasirci, 2013).…”