Ecological and biological factors controlling the concentrations of trace elements (As, Cd, Cu, Hg, Se, Zn) in delpinids Globicephala melas from the North Atlantic Ocean

Abstract

Ecological and biological factors controlling the concentrations of trace elements (As, Cd, Cu, Hg, Se, Zn) in delphinids Globicephala melas from the North Atlantic Ocean 'CNRS URA 1356, Service d'Ecotoxicologie. Faculte de Pharmacie, 1 rue Gaston Veil, F-44035 Nantes Cedex, France 'CNRS-IFREMER, CREMA I'Houmeau B.P. 5, F-17137 l'Houmeau, France ABSTRACT: Trace elements (As. Cd, Cu, Hg, Se and Zn) were determined in liver and kidney of pilot whales Glob~cephala melas Traill, 1809 collected from 7 schools caught at different seasons around the Faroe Islands. These and other biological data at our dlsposal enabled us to confirm and to define more accurately the relations shown prev~ously between age, sex and trace element concentrations in marine mammals. The most striking features were: (1) the elevated levels of Cd and Hg in pilot whales compared to other marine mammals and to minimum adverse-effect levels established for humans; (2) the biocumulative behaviour of Cd and Hg; (3) the high correlations between Hg and Se, predominantly influenced by age; and (4) the high correlations between Cd and Zn, the levels of which appear to be mainly dependent on the school to which the specimens belong. This last may be tentatively attributed to the fact that the schools sampled correspond to different sub-populations with different genetic charactenstics. The apparent metal tolerance of pilot whales and the health consequences to consumers of flesh of marine mammals are discussed.

Trace Element Concentrations in Liver of 16 Species of Cetaceans Stranded on Pacific Islands from 1997 through 2013

“…Four negative correlations were observed that corroborate findings in other studies: Cu/Hg, Cu/Cd, Zn/Se, and Zn/Hg (Agusa et al 2008; Caurant et al 1994; Roditi-Elasar et al 2003). The negative correlation between Cu and Cd could be indicative of a competitive protein binding interaction as the same metallothionein isoform involved in Cu regulation and homeostasis is responsible for Cd sequestration (Caurant et al 1994; Roditi-Elasar et al 2003).…”

“…The positive correlations between Cd/Hg and Cd/Se found are consistent with many other studies and are generally thought to be age-dependent. However, shared detoxification mechanisms could also contribute to these patterns (Agusa et al 2008; Caurant et al 1994; Monaci et al 1998; Seixas et al 2007). A strong positive Hg/Pb correlation was also observed, similar to that identified in striped dolphins ( Stenella coeruleoalba ) by Agusa et al (2008).…”

“…The negative correlation between Cu and Cd could be indicative of a competitive protein binding interaction as the same metallothionein isoform involved in Cu regulation and homeostasis is responsible for Cd sequestration (Caurant et al 1994; Roditi-Elasar et al 2003). Copper and Zn may co-vary because they both have similar homeostatic regulatory mechanisms (Caurant et al 1994; Lemos et al 2013; Roditi-Elasar et al 2003), and opposing age-related accumulation patterns could also account for each of these negative trace element correlations.…”

The Manx shearwater (Puffinus puffinus) as a candidate sentinel of Atlantic Ocean health

“…In birds, this ratio is almost never found [38,43,44], as in the present study, where a 1:5 ratio was found. This is possibly the reason why the correlation between Hg and Se found here is moderate, and not strong or very strong, as has been reported in several studies involving marine mammals [45-47], since this protection mechanism seems to be inherent to marine mammals [43]. Other studies involving aquatic birds have found a larger quantity of selenium relative to mercury, precluding the 1:1 molar ratio, as in the present study [42,44,48].…”

Trace elements in different species of cetacean from Rio de Janeiro coast

“…12 The study of trace elements in marine mammals is in its infancy in Brazil where few studies documented their concentrations in the tissues of cetaceans species with coastal habits such as Sotalia guianensis, Pontoporia blainvillei and oceanic habits such as Stenella frontalis. 7,11,[13][14][15][16][17] Furthermore, extensive studies of As, Cd, Cu, Pb, Se and Ag concentrations in cetaceans have been carried out in Northern Hemisphere 5,8,10,12,[18][19][20][21][22][23][24][25][26][27][28][29][30] but relatively little is known about contaminant levels in Southern Hemisphere cetaceans. [31][32][33][34][35] Then, the present research adds new insight to and complements the existing studies.…”