DBABVE-Artículos
URI permanente para esta colecciónhttps://hdl.handle.net/10953/109
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Examinando DBABVE-Artículos por Materia "Avoidance"
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Ítem Ecotoxicological assessment of the effects of fluoxetine on Daphnia magna based on acute toxicity, multigenerational reproduction effects, and attraction-repellence responses.(2023-01) Stremmel, Helmut; Weiss, Linda; Ramos-Rodríguez, Eloísa; Araújo, Cristiano; Parra-Anguita, GemaFluoxetine, a common pharmaceutical used as an antidepressant, is already considered potentially hazardous to biota due to its increasing use and detection in European, North American, and Asian rivers. We studied the effects of fluoxetine on Daphnia magna, as we hypothesized that fluoxetine might have harmful effects, short and long-term, at different levels: survival, behaviour, and reproduction (offspring production). We applied two different approaches: (i) a scenario at environmentally relevant concentrations (0.1–1.0 μg/L) and (ii) a scenario simulating a future worsening of contamination (1–800 μg/L) until the reach of lethal concentrations. In the former, we examined whether there are multigenerational effects on reproduction and on the avoidance/colonisation behaviour in previously exposed populations. In the latter, three responses were assessed: survival, avoidance behaviour and reproduction. We did not detect differences in the reproduction output of D. magna among the treatments over the three generations examined. Irrespective of the multigenerational treatment, D. magna colonised the environments with fluoxetine in a similar way. In the second scenario, we determined the lethal concentration for 50% of the population (96 h-LC50 = 365 μg/L), which, in spite of the toxic effect, was attractive to organisms during the avoidance tests (24 h); in fact, D. magna were attracted (no repellence) even to the highest concentrations of fluoxetine tested (800 μg/L). Lastly, in a 21-day chronic toxicity test the reproduction output of D. magna increased with higher concentrations of fluoxetine. This effect might be related to the fact that the organisms in the contaminated treatment began their first reproduction earlier, when compared to that in the control treatments. In conclusion, this study discusses an identified hazard for aquatic biota due to the fluoxetine attraction effect and a predictive assessment of the consequences expected if its indiscriminate use increases.Ítem Not Only Toxic but Repellent: What Can Organisms' Responses Tell Us about Contamination and What Are the Ecological Consequences When They Flee from an Environment?(MDPI, 2020-12) Araújo, Cristiano; Laissaoui, Abdelmourhit; Silva, Daniel C.V.R.; Ramos-Rodríguez, Eloísa; González-Ortegón, Enrique; Espíndola, Evaldo L.G.; Baldó, Francisco; Mena, Freylan; Parra-Anguita, Gema; Blasco, Julián; López-Doval, Julio; Sendra, Marta; Banni, Mohammed; Moreno-Garrido, IgnacioThe ability of aquatic organisms to sense the surrounding environment chemically and interpret such signals correctly is crucial for their ecological niche and survival. Although it is an oversimplification of the ecological interactions, we could consider that a significant part of the decisions taken by organisms are, to some extent, chemically driven. Accordingly, chemical contamination might interfere in the way organisms behave and interact with the environment. Just as any environmental factor, contamination can make a habitat less attractive or even unsuitable to accommodate life, conditioning to some degree the decision of organisms to stay in, or move from, an ecosystem. If we consider that contamination is not always spatially homogeneous and that many organisms can avoid it, the ability of contaminants to repel organisms should also be of concern. Thus, in this critical review, we have discussed the dual role of contamination: toxicity (disruption of the physiological and behavioral homeostasis) vs. repellency (contamination-driven changes in spatial distribution/habitat selection). The discussion is centered on methodologies (forced exposure against non-forced multi-compartmented exposure systems) and conceptual improvements (individual stress due to the toxic effects caused by a continuous exposure against contamination-driven spatial distribution). Finally, we propose an approach in which Stress and Landscape Ecology could be integrated with each other to improve our understanding of the threat contaminants represent to aquatic ecosystems.