Assessing Biota Accumulation Due to Contamination of Sediments by Storm Water Heavy Metals

Abstract

Evaluating sediment recontamination due to storm water discharges is important when evaluating the long-term effectiveness of sediment remediation efforts at reducing biological impacts. The bioaccumulation of the heavy metals zinc, nickel, copper, cadmium, mercury, and lead and the metalloid arsenic in a clam (Macoma nasuta) was studied in surficial sediments before and after storm water inputs from Paleta Creek, California, USA, during wet seasons in 2015 to 2016 and 2016 to 2017. The bioaccumulation was compared with bulk sediment concentrations and porewater concentrations measured by diffusion gradient in thin film devices. Significant reductions in biota accumulation and porewater concentrations were observed in samples collected after storm seasons compared with before storm seasons despite bulk sediment concentrations remaining the same or increasing. This was apparently the result of the deposition of storm water contaminants in low bioavailable forms. The bioaccumulation of all the measured contaminants showed a positive significant correlation with porewater concentrations (p < 0.1, α = 0.1) and weak or no correlations with bulk sediment concentration. In conclusion, observed bulk sediment recontamination due to storm water should not be assumed to lead directly to greater biota accumulation without bioavailability assessment.

Comparing Equilibrium Concentrations of Polychlorinated Biphenyls Based on Passive Sampling and Bioaccumulation in Water Column Deployments

“…The strongest correlations were detected between the passive sampler accumulation and organism bioaccumulation, with much weaker relationships found for comparisons between organism and sediment concentrations. Finally, Drygiannaki et al (2020) also reported stronger correlations between bioaccumulation of several toxic metals by clams ( Macoma nasuta ) and porewater concentrations based on DGTs compared with poor correlations with bulk sediment concentrations collected from a creek in California. While these examples demonstrate the usefulness of passive sampling as a surrogate for bioaccumulation, there is a special form of bioaccumulation, biomagnification, which results in exposure conditions that passive sampling may not be able to accurately capture during a conventional deployment.…”

Distribution of Uranium and Molybdenum in River Sediment near Molybdenite Mining Region: A Case Study in SW China

“…The Jinduicheng molybdenite ore is the second largest Mo deposit in Asia [8]. Longterm open-pit mining, accumulation and transportation of ore, and rain erosion can lead to a migration of main and trace elements from ore to aquatic sediment and soil [9][10][11][12][13]. The magmatic rocks in the Jinduicheng mining area are well developed, mainly acidic rocks like those of the granite porphyry series.…”