Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

Remobilisation of uranium from contaminated freshwater sediments by bioturbation

“…A fine layer of mucus-bound faecal pellets appeared at the top of the sediment. The sedimentwater interface area moderately increased, the oxygen penetration depth was reduced from 3 to 2 mm, and the diffusive oxygen uptake (DOU) of sediment was enhanced by 14 % (Lagauzère et al, 2009b). Previous reports have suggested that such observations are related to a global stimulation of microbial activity, notably through a supply of labile organic matter, the re-fractioning of sediment particles and the providing of new microniches for micro-organisms involved in diagenetic processes (e.g.…”

“…In addition to these reduction processes, oxidation of U (uraninite) can also be biotically favoured in the presence of nitrate or Fe(III) oxides, but it is unknown whether bacteria can obtain energy from this reaction (Borch et al, 2010). Comparatively Lagauzère et al (2009b). to these studies, the present experiment represents the first assessment of U contamination on microbial communities not previously exposed to pollution. More generally, toxicity of U to micro-organisms has been poorly investigated but appears to be lower than for other heavy metals (Nies, 1999).…”

Influence of tubificid worms on nutrient fluxes across water-sediment interface in fish farm settling ponds

“…Tubificids ingest buried sediments few centimetres in depth and faeces are deposited on the surface. Tubificid worms, through their burrowing, feeding and respiration movements, have been described to enhance not only nutrients and organic matter release from sediments (Fukuhara and Sakamoto, 1987;Mermillod-Blondin et al, 2005) but also the bacterial activity (Banta et al, 1999;Heilskov and Holmer, 2001;Mermillod-Blondin et al, 2005;Navel et al, 2011;Van de Bund et al, 1994) and oxygen consumption (Lagauzère et al, 2009;Mermillod-Blondin et al, 2005). Overall, bioturbation of bottom sediments at the sediment-water interface is currently gaining more attention in studies dealing with the functioning of aquatic ecosystems (Adámek and Maršálek, 2013).…”

Bioturbation/bioirrigation effect on thallium released from reservoir sediment by different organism types

“…Some studies have shown that the disturbance by benthic organisms was an important process affecting secondary pollutants released, because of the behavior as buried hole, ingestion, breathing, movement and discharge. These behaviors changed the porosity, compaction, pH and redox potential distribution of sediments to affect the mutual exchange of pollutants among the sediment, sediment pore water and the overlying water (Banta and Andersen, 2003;Granberg et al, 2008;Hunting et al, 2013;Josefsson et al, 2010;Lagauzere et al, 2009;Nogaro et al, 2013;Thibodeaux and Bierman, 2003). Bioturbation brought the contaminated sediment particles to the interface of sediment and water, that these particle resuspension to provide a contaminated habitat for the benthic organisms lived in the surface sediment (Gang et al, 2006;Mermillod-Blondin et al, 2008;Rhoads, 1974;Schaller, 2014;Simpson et al, 1998;Tengberg et al, 2003;Thibodeaux and Bierman, 2003;Widdows et al, 1998).…”