A field study of metal toxicity and accumulation by benthic invertebrates; implications for the acid‐volatile sulfide (AVS) model

Abstract

The toxicity and accumulation of Cd from sediment by benthic invertebrates was measured along a Cd gradient created in nature. The efficacy of acid-volatile sulfide (AVS) concentrations in improving the prediction of biological effects in nature is also evaluated for the first time. The Cd concentration of sediments from a shield lake in Quebec was adjusted to obtain Cd : AVS ratios of from 0.05 to 10. The sediments were then subjected to in situ colonization by invertebrates over a 1 -yr period. Cd concentrations in pore waters were very low at Cd : AVS molar ratios < 1 but increased markedly at ratios > 1. The results of previously published laboratory bioassays suggest that Cd would not be toxic to invertebrates when the molar ratio of Cd : AVS was c 1. The biological effects of contaminated sediment varied greatly among taxa, as determined by both an animal's sensitivity to Cd and the animal's behavior. The abundance of only one of the insect taxa present, Chironomus (salinarius gp.) sp., was significantly related to the Cd : AVS molar ratio. For the other taxa present, there was no relationship between either abundances or growth rates and the Cd : AVS molar ratio. The general lack of expected toxicity at the high Cd : AVS molar ratios in our field study can be explained by the differing sensitivities to Cd for the animal species used in the laboratory and in the field and by the relatively low concentrations of Cd in excess of AVS even at the highest Cd: AVS molar ratio.Most of the anthropogenic trace metals present in aquatic environments are associated with the solid phase of bottom sediments. The availability of these trace metals to benthic organisms has been the subject of numerous studies. Useful relationships have been found in the field between metal accumulation by animals and both dissolved metal concentrations (Tessier et al. 1993) and oxic sediment metal concentrations normalized to hydrous

Uptake and loss kinetics of Cd, Cr and Zn in the bivalves Potamocorbula amurensis and Macoma balthica:effects of size and salinity

“…The species-specific aspects of bioaccumulation could result from difference in feeding mode (filter feeding vs deposit feeding), exposure routes (dissolved vs food or benthic vs pelagic food web) and duration of exposure, as well as internal processes such as storage, detoxification and loss (Jackim et al 1977, Roesijadi & Robinson 1994, Wallace & Lopez 1996, Reinfelder et al 1997. Experimental studies have shown, for example, differences in metal uptake between suspension feeding and deposit feeding bivalves exposed in the same metal-ennched system (Crecelius et al 1982, Bryan 1985 or between benthos that feed from the water column versus benthos that feed on the sediments (Hare et al 1994, Warren et al 1998. It is proposed that some organisms can internally maintain or regulate approximately constant tissue levels of selected elements (most commonly Zn), regardless of external metal concentrations (Rainbow et al 1990 and references therein).…”

Use of X‐ray images and a contrasting agent to study the behavior of animals in soft sediments

“…is restricted to this zone, whereas the other taxa penetrate some distance into anoxic sediment. Because the concentrations of dissolved and particulate trace metals tend to change with the redox conditions (Hare et al 1994), the exposure of animals to these contaminants is likely tn differ depending on the depth to which they burrow.…”

“…), it has the potential to play a major role in bioturbation. We also wanted to determine the depth to which this insect and other sympatric taxa burrow to compare their potential relative exposures to sedimentary contaminants, the distributions of which tend to be strongly vertically stratified (Hare et al 1994).…”

“…The depth to which animals feed and burrow can influence the depth of the near-surface mixed layer (M&off 1995) as well as the exposure of animals to sedimentary contaminants (Hare et al 1994). In Fig.…”

Appropriate Applications of Sediment Quality Values for Metals and Metalloids

“…However, the EqP approach only accounts for a few metals and is limited by a variety of restrictions (14)(15)(16). Further, SQVs derived from the AVS/SEM model do not always show an improved ability to predict absence of sediment toxicity compared to SQVs based on dry-weight concentrations (17)(18)(19).…”