Influences on copper bioaccumulation, growth, and survival of the midge, Chironomus tentans, in metal-contaminated sediments

Abstract

I n f l u e n c e s on c o p p e r b i o a c c u m u l a t i o n , g r o w t h , a n d survival o f the midge, Chironomus tentans, in m e t a l -c o n t a m i n a t e d s e d i m e n t s * AbstractSediment bioassays with larvae of the midge, Chironomus tentans, were used to evaluate influences on the bioavailability and toxicity of copper (Cu) in sediments with a wide range of concentrations of metals, acid-volatile sulfide (AVS), and other physicochemical characteristics. Sediments were collected from sixteen lakes in Michigan, USA, and from twelve sites in the Clark Fork River drainage of Montana, USA, which are contaminated with metals from mining activities and from other anthropogenic sources. Bioassays with C. tentans larvae were conducted for ten days in a static-renewal test system, with endpoints of survival, growth, and metal bioaccumulation. Bioaccumulation of copper (Cu) was strongly correlated with Cu concentrations in porewater, and was increased significantly at Cu concentrations less than those affecting growth or survival. Midge survival and growth were not significantly correlated with concentrations of Cu in sediment or porewater, and were poorly predicted by ratios of acid-extractable metals to AVS in sediments. Principal components analysis indicated that Cu concentrations in porewater and bioaccumulation of Cu by midge larvae were influenced by AVS, sediment organic carbon, and porewater pH, and that toxicity was associated with high concentrations of Cu, high concentrations of zinc (Zn) and ammonia. No toxicity was observed in several sediments which contained low concentrations of AVS and high concentrations of Cu and Zn. In sediments which contain little AVS, bioavailability of metals may be controlled by constituents other than sulfides, such as organic matter and metal hydrous oxides. These results indicate that assessments of toxicity in metal-contaminated sediments should evaluate the importance of metal-binding phases other than sulfides, and the possible contributions of ammonia or other toxicants to toxicity in sediment bioassays.

Effects of copper on energy metabolism and larval development in the midge Chironomus riparius

“…Copper-induced Changes in Energetics in Chironomus riparius Larvae 235 Kosalwat and Knight, 1987;Timmermans et al, 1992;Besser et al, 1995;Watts and Pascoe, 1996;Pe´ry et al, 2003b;De Haas et al, 2004). In C. riparius exposed to this metal, growth reduction have been reported for the entire larval period (Pe´ry et al, 2003b;De Haas et al, 2004).…”

Effects of spatial and temporal variation of acid‐volatile sulfide on the bioavailability of copper and zinc in freshwater sediments

“…Surface grab samples and sediment cores were collected from two sites in the upper Clark Fork River, downstream from the historic mining and smelting district (CF1 and CF4), and four sites in Milltown Reservoir (Milltown), including one riverine site at the upper end of the reservoir (MR19), two sites in the main stem of the reservoir (MR7 and MR2), and one site in a shallow backwater area (MR10). These six sites were selected to represent the range of metal contamination and habitat types in the upper Clark Fork River and Milltown Reservoir, based on the results of previous studies [17][18][19]. Additional grab samples were collected from Rock Creek (RC), an uncontaminated tributary of the Clark Fork, for use as a reference sediment in bioassays.…”

“…Analyses of Cu in samples with greater Cu concentrations and all Zn analyses were conducted by AAS with atomization in an air-acetylene flame. Because Cu and Zn have been found to make up more than 95% of total molar concentrations of the five metals (Cd, Cu, Ni, Pb, and Zn) in SEM extracts from these sediments [19], concentrations of Cu and Zn in SEM extracts were used to estimate SEM:AVS ratios. The fractions of Cu and Zn in SEM fractions that would be ''free'' (i.e., not bound to AVS) were estimated based on the assumption that AVS would bind preferentially to Cu rather than Zn, due to the greater stability of CuS relative to ZnS [3]).…”

“…These differences may be responses to other sediment characteristics not measured in these samples, such as particle size distribution or concentrations of organic carbon or ammonia. Ammonia has been suggested as a possible source of toxicity in sediments from some Milltown sites [18,19].…”

“…Sediments from the Clark Fork and from Milltown Reservoir, a small impoundment about 200 km downstream from the mining area, have been shown to cause substantial bioaccumulation of metals and toxic effects in aquatic invertebrates [16][17][18]. Results of bioassays with Clark Fork and Milltown sediments suggest that growth and bioaccumulation of metals by larvae of the midge, Chironomus tentans, may be predicted by SEM:AVS ratios [19], but other recent studies also suggest that AVS concentrations vary spatially [14] and temporally (Table 1) in these sediments. The studies reported here examined the effects of spatial and temporal variation in AVS concentrations and SEM:AVS ratios on the bioavailability of Cu and Zn, as indicated by responses in C. tentans bioassays.…”