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Your search keyword '"Community tolerance"' showing total 2 results
Start Over Descriptor "Community tolerance" Journal science of the total environment
2 results on '"Community tolerance"'

1. Hypersaline mining effluents affect the structure and function of stream biofilm

Author

Lidia Vendrell-Puigmitja, Lorenzo Proia, Carmen Espinosa, Laura Barral-Fraga, Miguel Cañedo-Argüelles, Victoria Osorio, Carme Casas, Laia Llenas, Meritxell Abril, and European Commission

Subjects
Diatoms, History, Environmental Engineering, Aquatic biofilm, Polymers and Plastics, Salinity gradient, Freshwater salinisation, Pollution, Industrial and Manufacturing Engineering, Mining, Rivers, Biofilms, Humans, Environmental Chemistry, Business and International Management, Artificial streams, Waste Management and Disposal, Ecosystem, Community tolerance
Abstract

The salinisation of freshwater ecosystems is a global environmental problem that threatens biodiversity, ecosystem functioning and human welfare. The aim of this study was to investigate the potential impact of a realistic salinity gradient on the structure and functioning of freshwater biofilms. The salinity gradient was based on the real ion concentration of a mining effluent from an abandoned mine in Germany. We exposed biofilm from a pristine stream to 5 increasing salinities (3 to 100 g L-1) under controlled conditions in artificial streams for 21 days. We evaluated its functional (photosynthetic efficiency, nutrient uptake, and microbial respiration) and structural responses (community composition, algal biomass and diatom, cyanobacteria and green algae metrics) over time. Then we compared their responses with an unexposed biofilm used as control. The functionality and structure of the biofilm exposed to the different salinities significantly decreased after short-term and long-term exposure, respectively. The community composition shifted to a new stable state where the most tolerant species increased their abundances. At the same time, we observed an increase in the community tolerance (measured as Pollution-Induced Community Tolerance) along the salinity gradient. This study provides relevant information on the salt threshold concentrations that can substantially damage algal cells (i.e., between 15 and 30 g L-1). The results provide new insights regarding the response and adaptation of stream biofilm to salinity and its potential implications at the ecosystem level., We thank T.S and A.S from the Dresden Groundwater Research Center for the information about Menteroda abandoned mine provided. Lorenzo Proia that has received funding from the Postdoctoral Fellowships Programme Beatriu de Pinos, funded by the Secretary of Universities and Research (Government of Catalonia) and by the Horizon 2020 Programme of Research and Innovation of the European Union under the Marie Skłodowska-Curie Grant Agreement No. 801370 and by a Ramón y Cajal contract funded by the Spanish Ministry of Science and Innovation (RYC2020-029829-I). Miguel Cañedo-Argüelles was supported by the Serra-Hunter programme funded by the Generalitat of Catalunya and by a Ramón y Cajal contract funded by the Spanish Ministry of Science and Innovation (RYC2020-029829-I).

Published
2022
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2. Impacts of agricultural irrigation on nearby freshwater ecosystems: The seasonal influence of triazine herbicides in benthic algal communities.

Author

Lorente, Carmen, Causapé, Jesús, Glud, Ronnie N., Hancke, Kasper, Merchán, Daniel, Muñiz, Selene, Val, Jonatan, and Navarro, Enrique

Subjects
*IRRIGATION farming, *ECOSYSTEMS, *FRESHWATER ecology, *ALGAL communities, *PHOTOTROPINS, *TERBUTHYLAZINE
Abstract

A small hydrological basin (Lerma, NE Spain), transformed from its natural state (steppe) to rain-fed agriculture and recently to irrigation agriculture, has been monitored across four seasons of an agricultural year. The goal of this study was to assess how and whether agricultural activities impacted the nearby freshwater ecosystems via runoff. Specifically, we assessed the toxicity of three triazine herbicides, terbuthylazine, atrazine and simazine on the photosynthetic efficiency and structure of algal benthic biofilms (i.e., phototropic periphyton) in the small creek draining the basin. It was expected that the seasonal runoff of the herbicides in the creek affected the sensitivity of the periphyton in accord with the rationale of the Pollution Induced Community Tolerance (PICT): the exposure of the community to pollutants result in the replacement of sensitive species by more tolerant ones. In this way, PICT can serve to establish causal linkages between pollutants and the observed biological impacts. The periphyton presented significantly different sensitivities against terbuthylazine through the year in accord with the seasonal application of this herbicide in the crops nowadays. The sensitivity of already banned herbicides, atrazine and simazine does not display a clear seasonality. The different sensitivities to herbicides were in agreement with the expected exposures scenarios, according to the agricultural calendar, but not with the concentrations measured in water, which altogether indicates that the use of PICT approach may serve for long-term monitoring purposes. That will provide not only causal links between the occurrence of chemicals and their impacts on natural communities, but also information about the occurrence of chemicals that may escape from traditional sampling methods (water analysis). In addition, the EC50 and EC10 of periphyton for terbuthylazine or simazine are the first to be published and can be used for impact assessments. [ABSTRACT FROM AUTHOR]

Published
2015
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