The Role of Sediment Ingestion in Exposing Bottom‐Feeding Fish to Chemical Elements.

This article focuses on quantifying the role of incidental sediment ingestion in exposing seven species of bottom-feeding fish to inorganic contaminants. Using a composite sediment tracer variable based on concentrations of cobalt, chromium, nickel, titanium, vanadium, and yttrium, the study found that elements such as arsenic, chromium, nickel, aluminum, and lead are primarily ingested through sediment, whereas zinc, cadmium, and copper mainly come from sediment-free food. Notably, sediment ingestion accounted for up to 93% of nickel exposure in brown bullhead (Ameiurus nebulosus), and elevated aluminum and lead levels in suckers (family Catostomidae) suggest an additional oral source, likely metal oxides in biofilms (aufwuchs) coating benthic surfaces. The findings emphasize that including sediment ingestion is essential for accurately estimating oral exposure to metals in toxicological assessments of bottom-feeding fish.