Reviewing Cd, Hg and Pb Assessments and Effects in Elasmobranchs

Since the beginning of the industrial revolution, anthropogenic activities such as fossil fuel combustion and associated atmospheric deposition, mining, and smelting have dramatically increased the quantities of metals and metalloids entering marine environments (Förstner and Wittmann, 2012; Karimi et al., 2012). Due to their essential role in cellular homeostasis, many metals (e.g., Cu, Zn, Cd) persist at low concentrations in marine organisms, however, they can become toxic when they exceed threshold concentrations. Metals generally enter marine foodwebs via direct assimilation by marine primary producers (i.e., phytoplankton and cyanobacteria), which can biomagnify concentrations by several orders of magnitude relative to the ambient water column (Lee and Fisher, 2016, 2017). Biomagnification and bioaccumulation continue to occur with subsequent trophic transfers, the rate at which is driven by a suite of environmental (e.g., temperature) and biological processes (e.g., zooplankton allometry) (Wu et al., 2020).