Spatial and temporal variation of phytoplankton in subtropical stabilization ponds

Abstract

Aim: This study aimed at analyzing the phytoplankton community in two stabilization ponds of a subtropical region regarding spatial and temporal composition, richness, and abundance, as well as the respective relationships with local abiotic factors. For this purpose, we tested the hypothesis that eutrophic discharges of sewage results in the maintenance of high-density phytoplankton community, mainly Cyanobacteria and Chlorophyceae, both spatially and seasonally, as well as the occurrence of a spatial and seasonal similarity between phytoplankton richness and density in stabilization ponds. Methods: We carried out monthly samplings of the phytoplankton community and environmental variables, between March 2011 and February 2012, in two stabilization ponds located in the city of Cascavel, West Paraná State, Brazil. Results: We observed that the sampled months presented a clear distinction regarding environmental variability, which did not occur for the ponds. We identified 39 taxa, with Cyanobacteria as the most representative group both in richness and density. We records low diversity and evenness of species and low phytoplankton spatial and temporal variability without significant differences between the richness and density mean values according to the periods and sampling station. Conductivity, nutrients, dissolved oxygen and turbidity were the major structuring environmental variables of phytoplankton. Conclusion: Our results corroborated our hypotheses considering the similar spatial and temporal phytoplankton distributions because of abiotic conditions behaving similarly, as well as the direct connection of the ponds. This paper points out the importance of such studies to proper management, including cyanobacteria control and operational decisions regarding stabilization ponds and the export of undesirable inoculum for receiving water bodies.

Rapid Changes in the Phytoplankton Community of a Subtropical, Shallow, Hypereutrophic Lake During the Rainy Season

“…Additionally, the findings of this study suggest that significant rainfall variations cause extreme seasonal surface runoff and rapid changes in the water quality (Chlorophyll- a , DO, NH 4 + , and NO 3 – ) of this subtropical lake, as well as rapid variations in the phytoplankton community ( Figures 3 , 2 , 5 , 7 ). Studies on the temporal variations in the phytoplankton community have been carried out in temperate regions, but only a few have been reported in tropical or subtropical regions, such as Lake Cajititlán ( Limón-Macias et al, 1983 ; Umaña-Villalobos, 2010 ; Riediger et al, 2015 ; Li et al, 2018 ; Ma et al, 2019 ; Quevedo-Castro et al, 2019 ). The wet season in tropical and subtropical areas exacerbates the cultural eutrophication of surface water bodies when there is intensive agricultural activity in their basin ( Barbosa, 2009 ; Cunha et al, 2013 ).…”

Variability in phytoplankton community structure and influence on stabilization pond functioning

“…The opposite pattern was observed in the maturation pond, probably due to differences in pond structure. Species diversity increased from October to December in both ponds, probably due to increased rainfall, which carried particles of suspended solids into the pond, reducing the euphotic zone and decreasing dissolved oxygen concentration, favoring new species, especially flagellates (Riediger et al, 2015), such as Chlamydomonas sp., Chilomonas sp., Chlorogonium sp., and Collodictyon sp. because, these species are heterotrophic and do not need light to produce metabolites.…”

Comunidade Fitoplanctônica Como Indicadora Da Qualidade Ambiental Em Um Trecho Urbano Do Rio Jaguaribe, Semiárido Cearense

“…A maior representatividade de clorofíceas, especialmente no período chuvoso, no estudo pode estar relacionada com o hábito de vida cosmopolita da maioria dos gêneros e espécies de algas verdes e pelas características morfológicas/ fisiológicas (tamanho diminuto e crescimento acelerado), podendo ser encontradas em diferentes condições climáticas e limnológicas, tornando-as dominantes no número de táxons nas diferentes estações do ano (Bicudo e Menezes 2006;Riediger et al 2015;Mendes e Costa 2016). Além disso, no período de chuva, há o aumento de nutrientes na superfície da coluna de água, o que favorece as estratégias de assimilação dos nutrientes pelas clorofíceas (Aragão et al 2007).…”