Assessment of trace element content in liver and muscle of estuarine fishes from the impacted Indian River Lagoon (Florida, USA)

Trace element content in marine organisms remains a foremost environmental hazard, especially to fishes of ecological importance. However, the behavior of these contaminants across fishes with different trophic roles is yet to be fully understood, with tissue-specific assessments offering a valuable database. This study delves into the dynamics of multi-element accumulation among recreationally, economically, and ecologically important species ( Sciaenops ocellatus, Lutjanus griseus, Ariopsis felis, Centropomus undecimalis, Bairdiella chrysoura, Cynoscion nebulosus, Archosargus probatocephalus , Sphyrna tiburo ) from the Indian River Lagoon, an impacted estuary in Florida, USA. Forty-six inorganic elements, including some emerging contaminants (e.g., rare earth elements), were quantified in liver and muscle using inductively coupled plasma triple quadrupole mass spectrometry (ICP-QQQ). Contamination levels were lower than those reported in other estuaries worldwide and lower than the limits established by international monitoring organizations. Trophic status was a relevant driver of element accumulation, with low carnivores/omnivores (e.g., A. felis ) exhibiting the highest contamination levels in liver for most elements ( p < 0.05). The organic, less toxic forms of arsenic (e.g., arsenobetaine (AsB)) and selenium (e.g., selenomethioneine (SeMet); other Se species (OSS)) were the most abundant chemical species compared to inorganic forms ( p < 0.05), while mercury (Hg) was predominately present as toxic methylmercury (MeHg). Regarding total Hg concentrations in muscle, 17% of all individuals were above the international threshold (0.5 μg·g −1 ww) for safe human consumption. With these findings, we aim to improve our understanding of trace element content in IRL marine fishes, ultimately guiding us towards more effective ecological management strategies.