Acute toxicity and bioaccumulation of aqueous and sediment-bound metals in the estuarine amphipodMelita plumulosa

Abstract

The sensitivities of juvenile and adult amphipods to metals (Cd, Cu, Ni, Pb, and Zn) in whole sediment and water-only exposures were compared using a newly developed acute test with the estuarine species Melita plumulosa. Endpoints included survival and bioaccumulation in adults, and survival and growth (body length) in juveniles over 96 h water-only and 10 day sediment exposures. Juveniles were more sensitive than adults to metals, either bound to sediments or in the aqueous phase. Although LOEC values for copper and zinc in juvenile whole-sediment tests (820 and 2290 mg/kg dry weight, respectively) were high in comparison with interim sediment quality guideline values for individual metals (270 and 410 for copper and zinc respectively), they were generally within the range of concentrations found in contaminated sediments in local estuaries. Accumulation of metals, together with the low porewater metal concentrations in whole-sediment tests, indicated that the ingestion of sediment is an important source of zinc and copper and cause of toxicity in this species.

Development and application of whole‐sediment toxicity test using immobilized freshwater microalgae Pseudokirchneriella subcapitata

“…Marine benthic diatom (Cylindrotheca closterium) showed high sensitivity, and the EC50 value was reported to be 26 mg/kg Cu spiked in natural marine sand [6], which is lower than the EC50 values from the present study for coarsegrained sediments (142 mg Cu/kg) and fine-grained sediment (1,189 mg Cu/kg). Previous studies also reported some lethal toxicity data such as median lethal concentration values of Cu-spiked sediments to Tubifex tubifex ranging from 88 to 106 mg/kg [30], median lethal concentration of 1,310 mg Cu/kg for adult and 790 mg Cu/kg for juvenile amphipod Melita plumulosa [31], and median lethal concentration values of 426 mg Cu/kg for Chironomus riparius larvae after 10 d of exposure to Cu-spiked sediments [32]. The present study and previous studies suggest that different species have variable sensitivity toward toxicants in sediments, and their toxicity can be influenced by toxicants and sediment components.…”

It’s All in the Genes: How Genotype Can Impact Upon Response to Contaminant Exposure and the Implications for Biomonitoring in Aquatic Systems

“…1) is a commonly utilised sentinel species to assess the health of estuarine sediments (Ecotox Services Australasia, 2009). Originally isolated and described by Zeidler from specimens found in a coastal pool 100 m from the sea in northern New South Wales (Zeidler, 1989), M. plumulosa is an epibenthic amphipod endemic to eastern Australian waterways that can be found in the intertidal zone beneath rocks or shell-grit (King et al, 2006b;Lowry et al, 2000). Although the full geographic range of this amphipod has not been definitively established, historically it has been found in many waterways and estuaries between Brisbane and Melbourne along the east coast of Australia (Lowry et al, 2000); recently this amphipod has been sampled from the Pine River in Queensland down to the Yarra River in Victoria (Fig.…”

“…plumulosa and can tolerate a wide range of environmental conditions, including sediment particle sizes ranging from silt to gravel, salinities ranging from freshwater to seawater, as well as a wide range of temperatures King et al, 2006b). Under laboratory conditions, the average lifespan of M. plumulosa is 8-11 months; gravid females release live young that become sexually mature in four to six weeks .…”

“…Many contaminants often bind to and accumulate in aquatic sediments (Birch, 2000), the concentrations of which may not be reflected in the overlying pore water and water column. As this amphipod displays epibenthic behaviour and feeds on detritus by ingesting the sediment , it has been demonstrated that M. plumulosa is particularly sensitive to sediment-bound contaminants (King et al, , 2006b. Additionally, laboratory cultures of M. plumulosa are relatively simple to establish and maintain, as this amphipod has demonstrated robustness to a wide range of environmental conditions, and the optimal culture conditions have been well established .…”

“…These include a 42-day (full life-cycle) chronic whole-sediment test using metal-spiked sediments , a 10-day acute whole-sediment test using both adult and juvenile animals and metal-spiked sediments (King et al, 2006b), and more recently a 13-day reproduction test using both laboratory cultured amphipods as well as in situ testing (Mann et al, 2009(Mann et al, , 2010(Mann et al, , 2011. In all cases genetically heterogeneous amphipods were employed, with large numbers of individuals needed to offset the potential effects of inter-individual variation in toxicant response.…”