title: Use of diatom assemblages as biomonitor of the impact of treated uranium mining effluent discharge on a stream: case study of the Ritord watershed (Center-West France).
abstract: The rehabilitation of French former uranium mining sites has not prevented the contamination of the surrounding aquatic ecosystems with metal elements. This study assesses the impact of the discharge of treated uranium mining effluents on periphytic diatom communities to evaluate their potential of bioindication. A 7-month survey was conducted on the Ritord watercourse to measure the environmental conditions of microalgae, the non-taxonomic attributes of periphyton (photosynthesis and biomass) and to determine the specific composition of diatom assemblages grown on artificial substrates. The environmental conditions were altered by the mine waters, that contaminate the watercourse with uranium and with chemicals used in the pit-water treatment plants (BaCl2 and Al2(SO4)3). The biomass and photosynthetic activity of periphyton seemed not to respond to the stress induced by the treated mining effluents whereas the altered environmental conditions clearly impacted the composition of diatom communities. Downstream the discharges, the communities tended to be characterized by indicator species belonging to the genera Fragilaria, Eunotia and Brachysira and were highly similar to assemblages at acid mine drainage sites. The species Eunotia pectinalis var. undulata, Psammothidium rechtensis, Gomphonema lagenula and Pinnularia major were found to be sensitive to uranium effluents whereas Neidium alpinum and several species of Gomphonema tolerated this contamination. The relevance of diatoms as ecological indicator was illustrated through the changes in structure of communities induced by the discharge of uranium mining effluents and creates prospects for development of a bioindicator tool for this kind of impairment of water quality.
authors.affiliation: Laboratoire d'Ecotoxicologie des Radionucléides, Centre de Cadarache, IRSN, BP3, 13115, Saint Paul Lez Durance, France, olivier.herlory@gmail.com.
authors.forename: Olivier
authors.initials: O
authors.lastname: Herlory
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Bonzom
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Gilbin
authors.forename: Sandrine
authors.initials: S
authors.lastname: Frelon
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Fayolle
authors.forename: François
authors.initials: F
authors.lastname: Delmas
authors.forename: Michel
authors.initials: M
authors.lastname: Coste
mesh_terms: D017377:Diatoms / Q000187:drug effects* / Q000254:growth & development; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D005602:France; D008906:Mining; D014501:Uranium / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D014501:Uranium
references.citation: Ecotoxicology. 2011 Jan;20(1):187-201
references.pmid: 21107686
references.citation: Aquat Toxicol. 2002 Oct 2;60(1-2):61-73
references.pmid: 12204587
references.citation: Environ Pollut. 2008 Feb;151(3):532-42
references.pmid: 17629383
references.citation: Environ Pollut. 2001;112(1):61-71
references.pmid: 11202655
references.citation: Aquat Toxicol. 2005 Nov 30;75(4):343-53
references.pmid: 16260049
references.citation: Sci Total Environ. 2009 Oct 15;407(21):5620-36
references.pmid: 19647289
references.citation: Environ Toxicol Chem. 2002 Mar;21(3):626-32
references.pmid: 11883416
references.citation: Aquat Toxicol. 2008 Oct 20;90(1):29-36
references.pmid: 18801584
references.citation: J Environ Radioact. 2008 Apr;99(4):730-8
references.pmid: 18031876
references.citation: Water Res. 2002 Aug;36(14):3654-64
references.pmid: 12230212
references.citation: Ecotoxicology. 2008 Jan;17(1):47-58
references.pmid: 17952593
references.citation: Environ Monit Assess. 2009 Mar;150(1-4):351-63
references.pmid: 18386149
references.citation: Sci Total Environ. 2007 Mar 15;374(2-3):252-9
references.pmid: 17316767