Heavy metal distribution in southern Sea Lions (Otaria flavescens) from Argentina

A survey of trace element distribution in tissues of the dwarf sperm whale ( Kogia sima ) stranded along the South Carolina coast from 1990–2011

“…The Hg present in fish and squid is methylated (Caurant et al, 1996;Das et al, 2000;Gerpe et al, 2006), but the majority of Hg accumulated in marine mammal internal organs is inorganic mercury (Wagemann et al, 1998 andCardellicchio et al, 2002). Demethylation of methylHg, followed by the formation of a less toxic Hg-Se complex, is thought to occur in cetacean livers as a protective physiological mechanism (Das et al, 2000 andEndo et al, 2004).…”

“…Although metals generally occur at low concentrations in the oceans, marine organisms bioaccumulate trace elements with significant increase of metal burdens through the food web, especially toxic elements such as Hg or Cd (Gerpe et al, 2006;Meador et al, 1999). In odontocentes, Cd has been known to accumulate in the internal organs (Honda et al, 1983;Endo et al, 2002;Gerpe et al, 2006;Holsbeek et al, 1998) and bind to metallothioneins (Das et al, 2000).…”

“…Metals are typically heterogeneously distributed among tissues (Gerpe et al, 2006;Honda et al, 1983;Lahaye et al, 2007;Stavros et al, 2011;Zhou et al, 2001). A single factor ANOVA showed that in general, the liver had higher concentrations than the kidney for the following elements: Ag, Cr, Cu, Fe, Hg, Mn, Pb, and Sn; Sb was higher in the kidney.…”

“…In odontocentes, Cd has been known to accumulate in the internal organs (Honda et al, 1983;Endo et al, 2002;Gerpe et al, 2006;Holsbeek et al, 1998) and bind to metallothioneins (Das et al, 2000). Although Hg has a high affinity for metallothioneins, only a small amount of total Hg has been shown to be bound to metallothioneins in marine mammals (Caurant et al, 1996;Wagemann et al, 1998;Holsbeek et al, 1998).…”

Trace element bioaccumulation, tissue distribution, and elimination in odontocetes stranded in Florida and Georgia, USA over a 15-year period (2007–2021)

“…Odontocetes principally obtain nutrients through their diet, which consists primarily of teleost fishes and/or cephalopods (in variable proportions, depending on species). Ingestion is also the primary route of odontocetes' exposure to contaminants, including heavy metals [ 3 , 13 , 20 , 21 ]. Exposure to heavy metal contaminants constitutes a toxicological risk for odontocetes because it can result in oxidative stress, which can impair protein function, damage DNA, and disrupt membrane lipids [ [13] , [14] , [15] , [16] , [17] , 22 ], and has been linked to degenerative heart disease, immunodeficiency, and increased parasite infestations, among other disease risks [ 3 , 4 , 19 , [23] , [24] , [25] ].…”