Food chain transfer and exposure effects of selenium in salmonid fish communities in two watersheds in the Canadian Rocky Mountains

Abstract

Selenium (Se) concentrations and fish biomass were examined in streams in two mined watersheds to determine if juvenile salmonids reflect local Se exposure concentrations downstream of surface coal mines and to investigate the relationship between Se exposure and toxicity effects at the fish community level. Se concentrations were measured in water, biofilm, macroinvertebrates, and muscle tissues from juvenile westslope cutthroat trout (Oncorhynchus clarkii lewisi), bull trout (Salvelinus confluentus), rainbow trout (Oncorhynchus mykiss), and brook trout (Salvelinus fontinalis) in mine-affected and reference streams. Significant positive Se transfer relationships were found at each measured level of the lotic food chain.

Selenium dynamics in headwater streams of the central Appalachian coalfield

“…Among those factors are water Se concentrations. DeForest et al (, ) reported that EFs for Se tend to decrease as exposure increases, an observation that is consistent with our findings for EF sediment and EF biofilm (Supplemental Data, Figure S1A and B) and with findings by Kuchapski and Rasmussen () and Arnold et al (). For our data, EF leaf detritus also exhibited a weak negative relationship with water Se, which, although not statistically significant ( p = 0.24), did not contradict the pattern demonstrated by the other 2 particulate‐matter forms.…”

“…Selenium concentrations in benthic macroinvertebrates collected from reference and low‐SC streams were also similar to concentrations in benthic macroinvertebrates collected from reference and mining‐influenced streams in other studies (Casey ; Presser ; Arnold et al ; Kuchapski and Rasmussen ). In their analysis of Se contamination in aquatic environments in 29 field studies, Presser and Luoma () reported Se concentrations in macroinvertebrates from a wide range of aquatic habitats.…”

“…In the present study, EFs and second-level TTFs for Se are consistent with those of previous studies (Supplemental Data, Tables S3 and S4). Reported EF values for Se in the present study are similar to values found in a higher-order mining-influenced Appalachian stream (1104; Presser and Luoma 2010) and in other recent literature (Casey 2005;Presser 2013;Kuchapski and Rasmussen 2015). In addition, mean second-level trophic transfer of Se from primary-consumer macroinvertebrates to predator macroinvertebrates in the present study were less variable than first-level TTFs and within the range of values reported for primary to secondary trophic transfer of Se in other systems in central Appalachia .…”

“…Selenium concentrations in water, biofilm, and sediment in the reference streams of the present study were within or close to accepted background levels in freshwater environments (US Department of the Interior ), whereas Se concentrations in the particulate media of nonreference streams were within range or similar to Se concentrations collected in coal mining–influenced streams elsewhere in Appalachia (Presser and Luoma ; Presser ; Arnold et al ), in Alberta (Casey ), and in the Canadian Rockies (Kuchapski and Rasmussen ). Lower Se concentrations in particulate media, particularly in sediment, may be influenced by the relatively high‐gradient morphology of the present study streams, resulting in less Se accumulation through sediment and detrital pathways (Orr et al ).…”

“…Selenium concentrations in water, biofilm, and sediment in the reference streams of the present study were within or close to accepted background levels in freshwater environments (US Department of the Interior 1998), whereas Se concentrations in the particulate media of nonreference streams were within range or similar to Se concentrations collected in coal mininginfluenced streams elsewhere in Appalachia Presser 2013;Arnold et al 2017), in Alberta (Casey 2005), and in the Canadian Rockies (Kuchapski and Rasmussen 2015).…”