Nutrients versus emerging contaminants-Or a dynamic match between subsidy and stress effects on stream biofilms
dc.contributor.author
dc.date.accessioned
2017-06-02T11:46:59Z
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2017-06-02T11:46:59Z
dc.date.issued
2016-05-01
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0269-7491
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dc.description.abstract
Freshwater ecosystems are threatened by multiple anthropogenic stressors, which might be differentiated into two types: those that reduce biological activity at all concentrations (toxic contaminants), and those that subsidize biological activity at low concentrations and reduce it at high concentrations (assimilable contaminants). When occurring in mixtures, these contaminants can have either antagonistic, neutral or synergistic effects; but little is known on their joint effects. We assessed the interaction effects of a mixture of assimilable and toxic contaminants on stream biofilms in a manipulative experiment using artificial streams, and following a factorial design with three nutrient levels (low, medium or high) and either presence or absence of a mixture of emerging contaminants (ciprofloxacin, erythromycin, diclofenac, methylparaben, and sulfamethoxazole). We measured biofilm biomass, basal fluorescence, gross primary production and community respiration. Our initial hypotheses were that biofilm biomass and activity would: increase with medium nutrient concentrations (subsidy effect), but decrease with high nutrient concentrations (stress effect) (i); decrease with emerging contaminants, with the minimum decrease at medium nutrient concentrations (antagonistic interaction between nutrients subsidy and stress by emerging contaminants) and the maximum decrease at high nutrient concentrations (synergistic interaction between nutrients and emerging contaminants stress) (ii). All the measured variables responded linearly to the available nutrients, with no toxic effect at high nutrient concentrations. Emerging contaminants only caused weak toxic effects in some of the measured variables, and only after 3-4 weeks of exposure. Therefore, only antagonistic interactions were observed between nutrients and emerging contaminants, as medium and high nutrient concentrations partly compensated the harmful effects of emerging contaminants during the first weeks of the experiment. Our results show that contaminants with a subsidy effect can alleviate the effects of toxic contaminants, and that long-term experiments are required to detect stress effects of emerging contaminants at environmentally relevant concentrations
dc.description.sponsorship
This research was supported by the European Community's 7th Framework Programme (GLOBAQUA; 603629-ENV-2013-6.2.1)
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application/pdf
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eng
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Elsevier
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Reproducció digital del document publicat a: http://dx.doi.org/10.1016/j.envpol.2016.01.067
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© Environmental Pollution, 2016, vol. 212, p. 208-215
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Articles publicats (D-CCAA)
dc.rights
Attribution-NonCommercial-NoDerivs 3.0 Spain
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dc.subject
dc.title
Nutrients versus emerging contaminants-Or a dynamic match between subsidy and stress effects on stream biofilms
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/openAccess
dc.embargo.terms
Cap
dc.relation.projectID
info:eu-repo/grantAgreement/EC/FP7/603629/EU/MANAGING THE EFFECTS OF MULTIPLE STRESSORS ON AQUATIC ECOSYSTEMS UNDER WATER SCARCITY/GLOBAQUA
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.identifier.idgrec
026184
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