Volume 544, 15 February 2016, Pages 837–844
Highlights
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- High levels of mercury in bottlenose dolphins from Portugal.
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- Mercury only exceeded by levels reported in the Mediterranean and the Adriatic.
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- Evidence of bioaccumulation of several trace elements.
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- Essential trace elements were influenced by sex of bottlenose dolphins.
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- Evidence of stranding location effect on trace element levels.
Abstract
Both the conservation status of bottlenose dolphins (Tursiops truncatus)
(Habitats Directive 92/43/CEE, Annex II) and the Marine Strategy
Framework Directive demand for data on their ecology and anthropogenic
threats. To evaluate the bottlenose dolphin's toxicological status in
continental Portugal, several trace elements (As, Cd, Cu, Hg, Mn, Ni,
Pb, Se, Zn) were determined in 25 stranded individuals. The potential
effect of sex, body length and stranding location on trace element
concentrations was analysed. In the present study, bottlenose dolphins
presented high mercury levels, only exceeded by animals from the
Mediterranean and Adriatic seas. Only essential elements were influenced
by dolphin sex, whereas Cd, Hg and Pb bioaccumulated in larger
dolphins, and hepatic Hg and Cd concentrations were higher in the
northwest coast of continental Portugal. The location effect may relate
to variations in bottlenose diet and trace element availability,
according to the proximity to anthropogenic sources in the Atlantic
Iberian coast.
Graphical abstract
Keywords
- Marine mammals;
- Heavy metals;
- Pollution;
- North Atlantic
