Ecotoxicity of uranium to Tubifex tubifex worms (Annelida, Clitellata, Tubificidae) exposed to contaminated sediment.
In freshwater ecosystems, sediments act as an accumulation compartment for metallic pollutants as uranium. However, they are also the habitats of numerous benthic macroinvertebrates that directly influence the structure and functioning of such environments. Consequently, these organisms could be affected by uranium. This laboratory study aimed to assess the ecotoxicity of uranium on Tubifex tubifex through 12-day exposure to contaminated sediment (0-5980 microg U g(-1) dry wt). At high concentrations (>599 microg U g(-1) dry wt), malformations were observed, and survival, biomass and burrowing activity were all reduced. This relative high resistance in polluted environments can be explained mainly by the implementation of several processes as autotomy, regeneration ability, increased production of mucus, a hormetic effect on biomass and a probable strategy for avoiding the contaminated sediment. This study represents the first assessment of uranium impact on T. tubifex at realistic concentrations in sediments near mining sites.
Laboratoire de Radioécologie et d'Ecotoxicologie, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), DEI/SECRE, Cadarache bât. 186, BP 3, 13115 Saint-Paul-lez-Durance, Cedex, France.
Sandra
S
Lagauzère
Raphaële
R
Terrail
Jean-Marc
JM
Bonzom
D000818:Animals; D018533:Biomass; D017753:Ecosystem; D005618:Fresh Water; D019015:Geologic Sediments / Q000737:chemistry*; D008906:Mining; D009835:Oligochaeta / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D018570:Risk Assessment; D013997:Time Factors; D014501:Uranium / Q000378:metabolism / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
D014874:Water Pollutants, Chemical; D014501:Uranium