Trace elements in two odontocete species (Kogia breviceps and Globicephala macrorhynchus) stranded in New Caledonia (South Pacific)

Abstract

Liver, muscle and blubber tissues of two short-finned pilot whales (Globicephala macrorhynchus) and two pygmy sperm whales(Kogia breviceps) stranded on the coast of New Caledonia have been analysed for 12 trace elements (Al, Cd, Co, Cr, Cu. Fe, organic and total Hg, Mn, Ni, Se, V, and Zn). Liver was shown to be the most important accumulating organ for Cd, Cu, Fe, Hg, Se, and Zn in both species, G. macrorhynchus having the highest Cd, Hg, Se and Zn levels. In this species, concentrations of total Hg are particularly elevated, reaching up to 1452 microg g(-1) dry wt. Only a very low percentage of the total Hg was organic. In both species,the levels of Hg are directly related to Se in liver. Thus, a molar ratio of Hg:Se close to 1.0 was found for all specimens, except for the youngest K. breviceps. Our results suggest that G. macrorhynchus have a physiology promoting the accumulation of high levels of naturally occurring toxic elements. Furthermore, concentrations of Ni, Cr and Co are close to or below the detection limit in the liver and muscles of all specimens. This suggests that mining activity in New Caledonia, which typically elevates the levels of these contaminants in the marine environment, does not seem to be a significant source of contamination for these pelagic marine mammals.

Meeting Report: Methylmercury in Marine Ecosystems—From Sources to Seafood Consumers

“…Elevated environmental Hg concentrations have been widely documented in marine biota and extreme levels are regularly reported (Bustamante et al 2003; Kim et al 1996). The direct effects of elevated MeHg on marine biota can include impacts on neurologic end points and memory, locomotion, and cognition, as well as changes in brain neurochemical receptor density (Basu et al 2005; Scheuhammer et al 2008).…”

Analysis of mercury and methylmercury concentrations, and selenium:mercury molar ratios for a toxicological assessment of sperm whales (Physeter macrocephalus) in the most recent stranding event along the Adriatic coast (Southern Italy, Mediterranean Sea)

“…Binding of Se to Hg may reduce the bioavailability of Se and its antioxidant, antiviral, antimutagenic and anti-carcinogenic properties are consequently reduced, resulting in an increased susceptibility of marine mammals to oxidative injury (Ralston and Raymond, 2010). Se occurs at 1:1 M ratios with Hg in several marine mammal tissues such as liver, kidney and brain Bustamante et al, 2003). Ralston and others authors (Peterson et al, 2009;Ralston and Raymond, 2010;Sørmo et al, 2011) have suggested that excess selenium protects against mercury toxicity, and that Se:Hg molar ratios above 1 are largely protective for adverse effects related to mercury consumption.…”

Doğa ve Çiftlik Orkinoslarında (Thunnus thynnus L1758) Tespit Edilen Bazı Elementlerin Kemometrik Sınıfl andırması

“…Increased levels of trace elements are indicative of bioaccumulation of heavy metal toxins, mainly in liver tissues. Many fish species are threatened by such toxins and they are used to investigate the impact of environmental pollution [3][4][5] .…”