Ecotoxicity of uranium to Tubifex tubifex worms (Annelida, Clitellata, Tubificidae) exposed to contaminated sediment
Résumé
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 μg U g-1 dry wt). At high concentrations (>599 μg 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. © 2008 Elsevier Inc. All rights reserved.
Mots clés
uranium
annelid
autotomy
burrowing
concentration (composition)
ecotoxicology
heavy metal
macrobenthos
pollution effect
pollution exposure
sediment pollution
uranium
animal experiment
animal tissue
annelid worm
article
biomass
concentration response
congenital malformation
ecotoxicity
mining
nonhuman
regeneration
sediment
soil pollutant
soil pollution
survival rate
Tubifex tubifex
Animals
Biomass
Ecosystem
Fresh Water
Geologic Sediments
Mining
Oligochaeta
Risk Assessment
Time Factors
Uranium
Water Pollutants
Chemical
Annelida
Clitellata
Tubificidae