The Diffusive Gradients in Thin Films Technique Predicts Sediment Nickel Toxicity to the Amphipod Melita plumulosa

Abstract

The geographical shift of nickel mining to small island countries of the Southeast Asia and Melanesia region has produced a need to assess the environmental risk associated with increased sediment nickel exposure to benthic estuarine/marine biota. Chemical measurements of nickel concentration and potential bioavailability, including the use of diffusive gradients in thin films (DGT), were compared to effects on 10‐d reproduction of the epibenthic estuarine/marine amphipod Melita plumulosa in nickel‐spiked sediments and field‐contaminated sediments with different characteristics. The 10% effect concentrations (EC10s) for amphipod reproduction ranged from 280 to 690 mg/kg total recoverable nickel, from 110 to 380 mg/kg dilute acid–extractable nickel, and from 34 to 87 μg Ni/m2/h DGT‐labile nickel flux. Nickel bioavailability was lower in sediments with greater total organic carbon, clay content, and percentage of fine particles. Measurements of DGT‐labile nickel flux at the sediment–water interface integrated exposure to nickel from porewater, overlying water, and ingested sediment exposure pathways and were found to have the strongest relationship with the biological response. At most, there was a 29% reduction in 10‐d M. plumulosa reproduction relative to the control when exposed to nickel from field‐contaminated sediments collected from nickel laterite mining regions of New Caledonia. The DGT technique can be used as a complementary tool to measure the bioavailability of nickel in estuarine/marine sediments, especially sediments that are in nickel laterite mining regions where there are no or few toxicity data available for determining biological effects on local species. Based on the combined data set of the 3 nickel‐spiked sediments a DGT‐labile nickel EC10 threshold of 50 (30–69) μg Ni/m2/h was determined. Environ Toxicol Chem 2021;40:1266–1278. © 2020 SETAC

Metabarcoding Reveals Changes in Benthic Eukaryote and Prokaryote Community Composition along a Tropical Marine Sediment Nickel Gradient

“…The environmental variables measured in the present study accounted for between 55 and 66% of the total variation in community compositions. Future studies could include measurement of porewater metal concentrations or the flux of metal at the sediment–water interface using passive samplers such as diffusive gradients in thin films as additional lines of evidence (Spadaro and Simpson 2015; Gillmore et al 2020). Variations in confounding environmental factors, such as water depth and sediment particle size, were minimized in our sampling regime and site selection.…”

Enhancing Sediment Bioaccumulation Predictions: Isotopically Modified Bioassay and Biodynamic Modeling for Nickel Assessment

“…This study focuses on examining the bioaccumulation of nickel (Ni) in estuarine/marine sediment. This topic was chosen due to growing environmental concerns regarding the presence of elevated nickel in the estuarine and marine environments, , particularly within the global context of extracting nickel from surface-enriched nickel laterite deposits . These large-scale open-cast mining operations predominantly occur along tropical coastlines, leading to elevated nickel concentrations in estuarine sediments. − …”

Application of a Multi-Metal Stable-Isotope-Enriched Bioassay to Assess Changes to Metal Bioavailability in Suspended Sediments

“…For sediment metals, the most common chemical approaches involve wet-chemical extraction methods, including analysis of acid volatile sulfide and simultaneously extracted metals (AVS and SEM) ,, or a sequential extraction method (e.g., BCR extraction), to provide information on the binding strength between metals and solid phases, which are used to predict the bioavailable metal fraction. , However, these methods are criticized for not consistently discriminating bioavailable metals, resulting in data that may not improve risk assessment. , Recent progress with passive sampling techniques, such as diffusive gradients in thin-films, has offered some improvements in prediction effectiveness, − but the relatively long equilibration period (>24 h) of this technique precludes its application for measuring rapid changes in metal bioavailability.…”