Metal (As, Cd, Hg, and CH₃Hg) bioaccumulation from water and food by the benthic amphipod Leptocheirus plumulosus

Abstract

Benthic invertebrates may be exposed to metals in porewater, overlying water, ingested sediments, and other food particles. Rates and routes of metal exposure have important implications for predicting toxicity and interpreting toxicity test results. For the standard test amphipod Leptocheirus plumulosus, radiotracer techniques were used to quantify rates of Cd, As, Hg(II), and CH3Hg bioaccumulation from water and from suspension-feeding on labeled microalgae. Measured parameters were incorporated into a bioaccumulation model to predict steady-state metal concentrations in L. plumulosus and to evaluate the relative importance of aqueous and dietary uptake pathways across a range of ingested particle types and ingestion rates. Results indicate that ingested particles contribute strongly to metal bioaccumulation, and that feeding plasticity could strongly influence metal exposure. As L. plumulosus switches from suspension-feeding to deposit feeding or selectively feeds on particles for which it has a high assimilation efficiency, metal exposure and body burden will increase. At ingestion rates previously reported for deposit feeding (3 g/g/d), dietary metal sources dominate metal bioaccumulation and can be responsible for greater than 90% of metal bioaccumulated, regardless of metal partitioning or ingested particle type. Theses results suggest that more research on L. plumulosus feeding behavior is needed to produce a more complete mechanistic understanding of metal bioaccumulation.

Contrasting Food Web Factor and Body Size Relationships with Hg and Se Concentrations in Marine Biota

“…The high variability in Hg content likely explains the high variability in Hg:Se molar ratios observed within and among fish species [66]–[68]. Since Hg content in marine animals is primarily from dietary sources [25], [26], high Hg variability in animals likely reflects variability of Hg dietary exposure. Dietary exposure in natural populations is difficult to estimate.…”

Bioavailability, Toxicity, and Bioaccumulation of Quantum Dot Nanoparticles to the AmphipodLeptocheirus plumulosus

“…34,35 Although not measured here, our previous studies have shown that only 22% of initially dissolved Cd 2+ partitions to the algae in 20 ppt saline solutions. 36 …”

Toxicokinetics of cadmium in Palaemon varians postlarvae under waterborne and/or dietary exposure

“…Although copepods were offered in a freeze‐dried form and consequently no cadmium uptake could take place from the water, however, cadmium could still be adsorbed to the copepod's outer surface. Metal binding from the water to the diet has already been highlighted by several authors because it can facilitate the assimilation of metals in the midgut gland during digestion.…”