Abstract
Contamination by metals is among the most pervasive anthropogenic threats to the environment. Despite the ecological importance of marine apex predators, the potential negative impacts of metal bioaccumulation and biomagnification on the health of higher trophic level species remains unclear. To date, most toxicology studies in sharks have focused on measuring metal concentrations in muscle tissues associating human consumption and food safety, without further investigating potential impacts on shark health. To help address this knowledge gap, the present study evaluated metal concentrations in the gills, muscle, liver and rectal gland of coastal sharks opportunistically sampled from Brazilian waters and tested for potential relationships between metal bioaccumulation and general shark health and homeostatic balance metrics. Results revealed high metal concentrations in all four tissue types, with levels varying in relation to size, sex, and life-stage. Metal concentrations were also associated with serum biomarkers (urea, lactate, ALT, triglycerides, alkaline phosphatase, and phosphorus) and body condition, suggesting potential negative impacts on organismal health.
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•Alterations in hepatic markers with the bioaccumulation of Co, Fe, and Hg in the liver of sharks were observed.•Alterations in urea and lactate with the bioaccumulation of Fe and Hg in the gills of sharks were detected.•Alteration in phosphorus with the bioaccumulation of Co, Mn, and Hg in the rectal gland of sharks was also observed.•Body condition was influenced by metals, differing between males and females.•Energy mobilization was influenced by metals, differing between adults and juveniles.
