Patterns of Trace Element Accumulation in Waterfowl Restricted to Impoundments Holding Coal Combustion Waste

Abstract

Waterfowl are often exposed to and readily accumulate anthropogenic contaminants when foraging in polluted environments. Settling impoundments containing coal combustion waste (CCW) enriched in trace elements such as arsenic (As), selenium (Se), and mercury (Hg) are often used by free‐ranging migratory and resident waterfowl and represent potential sources for contaminant uptake. To assess accumulation of CCW contaminants, we experimentally restricted waterfowl to a CCW‐contaminated impoundment and quantified trace element burdens in blood, muscle, and liver tissues over known periods of exposure (between 3 and 92 d). From these data we developed models 1) to predict elemental bioaccumulation with increased exposure time, and 2) to predict muscle/liver burdens based on concentrations in blood as a nondestructive sampling method. Although Hg and As did not bioaccumulate in our waterfowl, we observed an increase in Se concentrations in muscle, liver, and blood tissues over the duration of our experiment. Furthermore, we found that blood may be used as an effective nondestructive sampling alternative to predict muscle and liver tissue concentrations in birds contaminated with Se and As through dietary exposure. These data provide unique insights into accumulation rates of contaminants for waterfowl utilizing habitats contaminated with CCW and demonstrate the efficacy of nonlethal sampling of waterfowl to quantify contaminant exposure. Environ Toxicol Chem 2020;39:1052–1059. © 2020 SETAC

Heavy metal concentrations in Canada geese, snow geese, mallards, and American coots from the northern Rocky Mountains in Montana

“…While the sample sizes for some of the species in this study are low (e.g., American coot, n = 6 ), thus limiting conclusions to toxicological exposure at population or species level, initial metal data for these species in the northern Rocky Mountains are essential for developing future, comprehensive toxicological assessments (Rattner 2009). Using hunter‐harvested birds for population‐level toxicological assessments is a common sampling methodology (Cristol et al 2012, Bond et al 2015, Leaphart et al 2020); however, caution should be used as these samples provide a relatively limited temporal window for an individual animal's exposure levels. In addition, although metal accumulation is hypothesized to occur between breeding habitat and point‐of‐harvest (Alhashemi et al 2011, Khan et al 2015), movement patterns determined from telemetry data would greatly enhance our understanding of metal exposure across spatial and temporal scales in this region (Wolf et al 2010, Vyas et al 2022).…”

Bioaccumulation of Mercury and Radiocesium in Waterfowl Introduced to a Site with Legacy Contamination

“…For many decades, waterfowl have been shown to be important accumulators of various anthropogenic pollutants, including heavy metals and radionuclides (Cristol et al, 2012 ; Fendley et al, 1977 ; Fimreite et al, 1971 ; Golden & Rattner, 2003 ; Hernández et al, 1999 ; Leaphart et al, 2020 ). Given their mobility and propensity to use multiple waterbodies across large spatial scales, data on time‐specific bioaccumulation rates of contaminants are needed to better understand potential risks to waterfowl as well as to humans and other predators (Leaphart et al, 2020 ). Our data demonstrate that ring‐necked ducks accumulated neither Hg nor 137 Cs during the present study period, whereas mallards readily accumulated both contaminants in blood, muscle, and liver.…”

“…Although it is well established that both Hg and 137 Cs can accumulate in exposed waterfowl, knowledge of the rate of accumulation over time for these contaminants within the environment is lacking, with few aviary studies in existence for birds under laboratory conditions for Hg (Bearhop et al, 2000;Heinz, 1987). Leaphart et al (2020) modeled arsenic and selenium bioaccumulation over time in ring-necked ducks experimentally restricted to a basin containing coal fly ash, although Hg bioaccumulation was negligible in that study, likely given its bioavailability and presence of selenium. Studies conducted on the US Department of Energy's Savannah River Site have examined accumulation rates of 137 Cs in wood ducks (Fendley et al, 1977) and ring-necked ducks (Kennamer et al, 2017), but did not compare potential effects of differences in foraging strategies (i.e., collection of dietary items via dabbling vs. diving).…”