Biodynamic modelling and the prediction of Ag, Cd and Zn accumulation from solution and sediment by the polychaete Nereis diversicolor

Abstract

Biodynamic modelling has been used to predict bioaccumulated concentrations of Ag, Cd and Zn in the deposit-feeding polychaete Nereis diversicolor from 5 metal-contaminated estuaries in SW England and a relatively non-contaminated estuary in SE England. The modelling employed previously measured physiological parameters of bioaccumulation -uptake rate constant, assimilation efficiency (AE) and efflux rate constants after uptake from water and sediment ingestion -and measured sediment metal concentrations specific for each population. AEs were considered to relate to metals in the organic component of the ingested sediment and ingestion rates were therefore expressed in these terms, with the further assumption that the total sediment metal concentration is a proxy for the metal concentration in the sediment organic component. A range of growth rate constants was extracted from the literature, as were concentration ranges of dissolved Ag, Cd and Zn in contaminated coastal waters. The model showed that > 99% Cd and > 98% Zn accumulated by N. diversicolor is derived from sediment ingestion; more bioaccumulated Ag is derived from solution, the percentage contribution of the dissolved source increasing from 46 to 80% with an increase in Ag dissolved concentration from low to high values for coastal waters. Bioaccumulated metal concentrations predicted from the model generally showed excellent agreement with independently measured concentrations in field-collected worms, supporting the assumptions made in the model. KEY WORDS: Bioavailability · Biodynamic modelling · Sediments · Uptake · Efflux Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 390: [145][146][147][148][149][150][151][152][153][154][155] 2009 chaetes (Selck et al. 1998, Wang et al. 1998, Casado-Martinez et al. 2009a, sipunculids , bivalve molluscs (Lee et al. 1998, Griscom et al. 2000, 2002 and crustaceans . When applied to deposit feeders, these models show the importance of ingested sediments as (often) the predominant source of metals with potentially direct toxic effects to the ingestor but also potentially indirect toxic effects to predators higher up the local food chain (Rainbow et al. 2004(Rainbow et al. , 2006.Most applications of biodynamic studies to date have considered relatively broad applications, assuming that physiological parameters are species-specific and relatively constant. Fewer studies have addressed population differences and their implications for bioaccumulation, partly because such specific studies probably require determination of population-specific physiological parameters (e.g. Rainbow et al. 2009).Here we apply biodynamic modelling to compare bioaccumulation and the relative importance of water and sediment as sources of the trace metals Ag, Cd and Zn among 6 populations of the widespread infaunal estuarine polychaete Nereis diversicolor. N. diversiciolor can feed using a variety of mechanisms (Harley 1950), but not least as a deposit feeder ingesting local surfa...

Bioaccumulation and oxidative stress responses measured in the estuarine ragworm (Nereis diversicolor) exposed to dissolved, nano- and bulk-sized silver

“…It may be possible that such inhibition is due to either through direct action of metal on the enzyme or indirectly via the production of ROS (Ahn et al, 2014;Al Kaddissi et al, 2014). The accumulation of metals by N. diversicolor, including Ag, has been shown to occur primarily by sediment ingestion (Rainbow et al, 2009). Similarly Ag NPs were shown to be internalized into the tissue from the gut lumen of this worm following 10 day exposure (García-Alonso et al, 2011).…”

“…Released Ag NPs may preferentially accumulate in sediments, leading to incidental ingestion by deposit-feeding benthic organisms (Farre et al, 2009), such as the estuarine ragworm, Nereis diversicolor. Given their widespread distribution, ecological importance and extensive use as a monitor of trace metal bioavailabilities (Rainbow et al, 2009), N. diversicolor is an ideal species to determine the environmental impact of NPs. Laboratory exposures of N. diversicolor to Ag NPspiked sediments have been conducted to mimic potential real world eventualities with endpoints including uptake and subcellular localization (García-Alonso et al, 2011), and toxicity (Cong et al, 2011).…”

The influence of sediment particle size and organic carbon on toxicity of copper to benthic invertebrates in oxic/suboxic surface sediments

“…The toxicity of metal contaminants in sediments to benthic organisms is influenced by the chemistry and speciation of the metal, the properties of the sediments, and the varying exposure pathways of different organisms [4][5][6]. The exposure and bioavailability of metals from both the dissolved phase (through exposure to pore water, burrow water, or overlying water) and sediment phases (through ingestion of particles) and the sensitivity of the organism to these metal exposures all need to be understood to predict effects [7][8][9][10].…”

Accumulation and effects of sediment-associated silver nanoparticles to sediment-dwelling invertebrates

“…For instance, sediment has been found to be an important pathway for Ag uptake in the polychaetes Arenicola marina and Nereis diversicolor (i.e., more than 70% and 20-54% of the Ag body-burden was related to sediment ingestion, respectively; Casado-Martinez et al, 2009;Rainbow et al, 2009), but whether the same applies for Ag NPs is not known. In general, deposit-feeders meet their nutritional requirements from the organic fraction of ingested sediment, which is known to be a relatively poor food source (i.e., estuarine sediments typically contain less than 5% organic matter) (Lopez and Levinton, 1987).…”