Selenium Bioaccumulation Across Trophic Levels and Along a Longitudinal Gradient in Headwater Streams

Abstract

Toxic effects of selenium (Se) contamination in freshwaters have been well documented. However, study of Se contamination has focused on lentic and larger order lotic systems, whereas headwater streams have received little scrutiny. In central Appalachia, surface coal mining is a common Se source to headwater streams, thus providing a useful system to investigate Se bioaccumulation in headwater food chains and possible longitudinal patterns in Se concentrations. Toward that end, we assessed Se bioaccumulation in 2 reference and 4 mining‐influenced headwater streams. At each stream, we sampled ecosystem media, including streamwater, particulate matter (sediment, biofilm, leaf detritus), benthic macroinvertebrates, salamanders, and fish, every 400 m along 1.2‐ and 1.6‐km reaches. We compared media Se concentrations within and among streams and evaluated longitudinal trends in media Se concentrations. Selenium concentrations in sampled media were higher in mining‐influenced streams compared with reference streams. We found the highest Se concentrations in benthic macroinvertebrates; however, salamanders and fish bioaccumulated Se to potentially harmful levels in mining‐influenced streams. Only one stream demonstrated dilution of streamwater Se with distance downstream, and few longitudinal patterns in Se bioaccumulation occurred along our study reaches. Collectively, our results provide a field‐based assessment of Se bioaccumulation in headwater food chains, from streamwater to fish, and highlight the need for future assessments of Se effects in headwater streams and receiving downstream waters. Environ Toxicol Chem 2020;39:692–704. © 2020 SETAC

Selenium Distribution and Trophic Transfer in the Periphyton–Benthic Macroinvertebrate Food Chain in Boreal Lakes Downstream from a Milling Operation

“…Similarly to Se distribution, Se bioaccumulation in BMI taxa was greater at sites with higher Se exposure (Sites 1, 2, and 4), a trend also reported by others (Cianciolo et al, 2020;Muscatello & Janz, 2009;Orr et al, 2006). At these sites, Se concentrations in some BMI taxa (e.g., caddisflies, chironomids, dragonfly nymphs, and gastropods) exceeded the selected benchmark of 4 µg/g dry weight (BCMoE, 2014) and were comparable to the lower range of Se concentration data for chironomids (9.4-87.9 µg/g dry wt) and predatory BMI taxa (8.7-94 µg/ g dry wt) sampled from other uranium mine-influenced lakes in northern Saskatchewan (Muscatello et al, 2008;Wiramanaden et al, 2010).…”

“…At these sites, Se concentrations in periphyton were comparable to those observed to reduce fecundity and survival of mayflies, genus Centroptilum (Conley et al, 2009(Conley et al, , 2014, sampled in Vulture Lake. Selenium enrichment in periphyton was at the same order of magnitude as reported in the literature for sites receiving continuous Se input (Arnold et al, 2017;Cianciolo et al, 2020). Furthermore, and as other studies indicated (DeForest et al, 2007;Graves et al, 2019a;Markwart et al, 2019;Whitmore et al, 2018), greater Se enrichment in periphyton was observed at sites with relatively low aqueous Se concentrations, such as Sites 6 and 10 (reference); and inversely, lower enrichment was observed in Vulture Lake and at Site 4, near the diluted effluent diffuser.…”

“…Recent studies, however, have demonstrated adverse effects of Se (selenite) on benthic macroinvertebrate richness and density at concentrations below the current Canadian benchmark of 1 µg/L (Graves et al, 2019b). Also, in mine-influenced streams, benthic macroinvertebrate taxa bioaccumulated the highest Se concentrations among all taxa analyzed, including fish and salamanders (Cianciolo et al, 2020). Selenium bioaccumulation, maternal transfer, and reduction of fecundity in mayfly Centroptilum triangulifer (formerly Neocloeon) feeding on periphyton enriched in Se (from coal ash leachate) were reported in laboratory studies (Conley et al, 2009(Conley et al, , 2014Scheibener et al, 2017).…”

Coal‐mining intensity influences species and trait distributions of stream fishes in two Central Appalachian watersheds

“…Fine‐sedimentation was, unexpectedly, not a prominent stressor, and relationships between habitat and reproductive guilds were counterintuitive. Our results are consistent with studies highlighting the influence of mining‐impacted stream production on biotic assemblages (Cianciolo et al., 2020; Northington et al., 2011; Presser, 2013; Voss & Bernhardt, 2017; Whitmore et al., 2018) and emphasise the complexity of mining impacts manifest through novel species‐ and trait‐based sensitivities paired with water and habitat quality alterations.…”

Biological Factors Moderate Trace Element Accumulation in Fish along an Environmental Concentration Gradient

“…Correlations between water column trace element concentrations and those in fish in other studies are variable (Anatone et al 2020;Cianciolo et al 2020;Donadt et al 2021). Bioavailability of a trace element is partially dependent on the state it occurs in.…”