Drivers of biomagnification of Hg, As and Se in aquatic food webs: A review

Arsenic and Mercury Distribution in an Aquatic Food Chain: Importance of Femtoplankton and Picoplankton Filtration Fractions

“…Although it is well established that bacteria and archaea are the principal drivers of biogeochemical cycling of Hg and As in nature, to our knowledge their role as metal(loid) entry points into aquatic food chains has not been examined to any extent. Based on an assessment of the primary literature as well as summary reviews (Córdoba-Tovar et al, 2022), we conclude that sampling and filtration methods in aquatic food chain studies most often use 3.0-μm filtration as a cutoff to separate soluble dissolved versus biomass-containing metal(loid)s. Yet, this completely omits most bacteria and archaea (certainly unicellular planktonic cells). Another common filtration cutoff is 0.22 μm, sometimes used to define Hg or As associated with dissolved organics (see French et al, 2014); but there is considerable literature that describes 0.2-μm filterable bacteria.…”

“…Another specific point of interest in the present study concerned food chain entry points of Hg and As. Based on an assessment of the primary literature as well as summary reviews (Córdoba-Tovar et al, 2022), sampling and filtration methods in aquatic food chain studies most often use 3.0-μm filtration as a cutoff to separate soluble dissolved versus biomass containing metal(loid)s. In addition to the above-cited USGS studies, our own extensive efforts have documented aquatic solute and gas chemistries, as well as the microbiome (bacteria and archaea) throughout the lake (Clingenpeel et al, 2011(Clingenpeel et al, , 2013Kan et al, 2011Kan et al, , 2016Lovalvo et al, 2010), identifying lake locations that differ significantly with respect to metal(loid) inputs and concentrations, and thus are ideally suited to examine As and Hg bioaccumulation and biomagnification in the Yellowstone Lake aquatic food chain. Specifically, the present study examined and contrasted As and Hg in femto-and picoplankton to test the hypothesis that these tiny plankton are principal entry points for metal(loid)s into aquatic food chains.…”

Toxic metal(loids) levels in the aquatic environment and nuclear alterations in fish in a tropical river impacted by gold mining

“…Once these contaminants enter the water body they can precipitate to the bottom and accumulate in sediments and be present in the water column. In addition, they can increase their toxic potential as they react with other environmental constituents (Córdoba-Tovar et al, 2022;Wang et al, 2023).…”

Toxicity of arsenic(

“…They are produced by biotransformation of inorganic As V and are transformed back to inorganic As V upon release into the marine environment (Duncan et al 2015). The ability of marine organisms to bioaccumulate arsenic as inorganic and organic forms (predominantly as arsenobetaine (AB)) means that arsenic can be transferred to higher trophic levels of the food chain and conflicting evidence exists for arsenic biomagnification as well as biodilution (Barwick and Maher 2003;Córdoba-Tovar et al 2022).…”