Ecological impacts of freshwater algal blooms on water quality, plankton biodiversity, structure, and ecosystem functioning

Alves Amorım, Cıhelıo
Moura, Ariadne do Nascimento
Harmful algal blooms are among the emerging threats to freshwater biodiversity that need to be studied further in the Anthropocene. Here, we studied freshwater plankton communities in ten tropical reservoirs to record the impact of algal blooms, comprising different phytoplankton taxa, on water quality, plankton biodiversity, and ecosystem functioning. We compared water quality parameters (water transparency, mixing depth, pH, electrical conductivity, dissolved inorganic nitrogen, total dissolved phosphorus, total phosphorus, chlorophyll-a, and trophic state), plankton structure (composition and biomass), biodiversity (species richness, diversity, and evenness), and ecosystem functioning (phytoplankton:phosphorus and zooplankton:phytoplankton ratios as a metric of resource use efficiency) through univariate and multivariate analysis of variance, and generalized additive mixed models in five different bloom categories. Most of the bloom events were composed of Cyanobacteria, followed by Dinophyta and Chlorophyta. Mixed blooms were composed of Cyanobacteria plus Bacillariophyta, Chlorophyta, and/or Dinophyta, while non-bloom communities presented phytoplankton biomass below the threshold for bloom development (10 mg L-1, WHO alert level 2). Higher phytoplankton biomasses were recorded during Cyanobacteria blooms (15.87-273.82 mg L-1) followed by Dinophyta blooms (18.86-196.41 mg L-1). An intense deterioration ofwater quality, including higher pH, eutrophication, stratification, and lower water transparency, was verified during Cyanobacteria and mixed blooms, while Chlorophyta and Dinophyta blooms presented lower pH, eutrophication, stratification, and higher water transparency. All bloom categories significantly impacted phytoplankton and zooplankton structure, changing the composition and dominance patterns. Bloom intensity positively influenced phytoplankton resource use efficiency (R-2 = 0.25; p < 0.001), while decreased zooplankton resource acquisition (R-2 = 0.51; p < 0.001). Moreover, Cyanobacteria and Chlorophyta blooms negatively impacted zooplankton species richness, while Dinophyta blooms decreased phytoplankton richness. In general, Cyanobacteria blooms presented low water quality and major threats to plankton biodiversity, and ecosystem functioning. Moreover, we demonstrated that biodiversity losses decrease ecosystem functioning, with cascading effects on plankton dynamics. (C) 2020 Elsevier B.V. All rights reserved.


Cyanobacterial blooms in freshwater bodies from a semiarid region, Northeast Brazil: A review
Moura, Ariadne do Nascimento; Aragao-Tavares, Nisia K. C.; Alves Amorım, Cıhelıo (2018-01-01)
Harmful cyanobacterial blooms have caused several problems in freshwater environments due to their prolific growth and the harmful cyanotoxins produced by some species. The occurrence of these organisms has increased in recent decades due to climate change and eutrophication, although most studies are from temperate regions in the Northern hemisphere. This review presents data about cyanobacteria occurrence, dominance, and toxicity events in freshwater bodies in a semiarid region of Northeast Brazil, in the...
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Jeppesen, Erik; Meerhoff, Mariana; Davidson, Thomas A.; Trolle, Dennis; Sondergaard, Martin; Lauridsen, Torben L.; Beklioğlu, Meryem; Brucet, Sandra; Volta, Pietro; Gonzalez-Bergonzoni, Ivan; Nielsen, Anders (PAGEPress Publications, 2014-01-01)
Freshwater ecosystems and their biodiversity are presently seriously threatened by global development and population growth, leading to increases in nutrient inputs and intensification of eutrophication-induced problems in receiving fresh waters, particularly in lakes. Climate change constitutes another threat exacerbating the symptoms of eutrophication and species migration and loss. Unequivocal evidence of climate change impacts is still highly fragmented despite the intensive research, in part due to the...
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Toxic algal blooms are occurring on a more frequent basis and have been shown to cause harm in higher trophic levels. The diatom toxin domoic acid, produced by the genus Pseudo-nitzschia, has been shown to be responsible for the contamination of shellfish, zooplankton, and fish around the world. Contaminations have impacted various economical markets as well. These primary consumers (vectors) have a variety of responses to blooms of toxic phytoplankton species ranging from avoidance to ingestion of the alga...
Adaptive strategies to mitigate the impacts of climate change on European freshwater ecosystems (REFRESH)
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Understanding how freshwater ecosystems will respond to future climate change is essential for the development of policies and implementation strategies needed to protect aquatic and riparian ecosystems. The future status of freshwater ecosystems is however, also dependent on changes in land-use, pollution loading and water demand. In addition the measures that need to be taken to restore freshwater ecosystems to good ecological health or to sustain priority species as required by EU Directives need to be d...
Freshwater salinisation: a research agenda for a saltier world
Cunillera-Montcusí, David; Beklioğlu, Meryem; Cañedo-Argüelles, Miguel; Jeppesen, Erik; Ptacnik, Robert; Amorim, Cihelio A.; Arnott, Shelley E.; Berger, Stella A.; Brucet, Sandra; Dugan, Hilary A.; Gerhard, Miriam; Horváth, Zsófia; Langenheder, Silke; Nejstgaard, Jens C.; Reinikainen, Marko; Striebel, Maren; Urrutia-Cordero, Pablo; Vad, Csaba F.; Zadereev, Egor; Matias, Miguel (2022-05-01)
© 2021 The AuthorsThe widespread salinisation of freshwater ecosystems poses a major threat to the biodiversity, functioning, and services that they provide. Human activities promote freshwater salinisation through multiple drivers (e.g., agriculture, resource extraction, urbanisation) that are amplified by climate change. Due to its complexity, we are still far from fully understanding the ecological and evolutionary consequences of freshwater salinisation. Here, we assess current research gaps and present...
Citation Formats
C. Alves Amorım and A. d. N. Moura, “Ecological impacts of freshwater algal blooms on water quality, plankton biodiversity, structure, and ecosystem functioning,” SCIENCE OF THE TOTAL ENVIRONMENT, vol. 758, pp. 0–0, 2021, Accessed: 00, 2023. [Online]. Available: