Short-term arsenic exposure reduces diatom cell size in biofilm communities | L'exposition à court terme à l'arsenic provoque la réduction de taille diatomique dans les communautés périphytiques
2016
Barral Fraga, L. | Morin, Soizic | Rovira, M.D.M. | Urrea, G. | Magellan, K. | Guasch, H. | INSTITUTE OF AQUATIC ECOLOGY GIRONA ESP ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Ecosystèmes aquatiques et changements globaux (UR EABX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | LINCOLN UNIVERSITY BIO PROTECTION RESEARCH CENTRE LINCOLN NZL ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA
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显示更多 [+] 显示较少 [-]英语. Arsenic (As) pollution in water has important impacts for human and ecosystem health. In freshwaters, arsenate (AsV) can be taken up by microalgae due to its similarity with phosphate molecules, its toxicity being aggravated under phosphate depletion. An experiment combining ecological and ecotoxicological descriptors was conducted to investigate the effects of AsV (130 microg L-1 over 13 days) on the structure and function of fluvial biofilm under phosphate-limiting conditions. We further incorporated fish (Gambusia holbrooki) into our experimental system, expecting fish to provide more available phosphate for algae and, consequently, protecting algae against As toxicity. However, this protection role was not fully achieved. Arsenic inhibited algal growth and productivity but not bacteria. The diatom community was clearly affected showing a strong reduction in cell biovolume; selection for tolerant species, in particular Achnanthidium minutissimum; and a reduction in species richness. Our results have important implications for risk assessment, as the experimental As concentration used was lower than acute toxicity criteria established by the USEPA.
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