Stranded cetaceans as indicators of mercury pollution in the Mediterranean Sea

Abstract

Concentrations of Hg were determined in tissues (muscle, heart, kidney, lung and liver) of two cetacean species (Stenella coeruleoalba and Tursiops truncatus) stranded along the Italian coasts during the period 2000-2009 and compared with those previously reported by other authors from different areas of the Mediterranean basin. The highest concentrations of Hg were found in liver samples of both species (8.4-1752 mg·kg −1 dry weight for S. coeruleoalba and 9.6-1404 mg·kg −1 d.w. for T. truncatus). Statistically significant dissimilarities of Hg concentrations were recorded in muscle and liver tissues of S. coeruleoalba stranded in different geographical areas of the Mediterranean Sea as apparent direct response to uneven impacts of Hg pollution in the basin. A noteworthy outcome was that cetaceans stranded on the French coasts showed significantly higher levels of Hg contamination than those from other Mediterranean areas while the eastern part of the basin evidences the lowest Hg concentrations in the studied organisms. Moreover, the results of this study tentatively suggest the existence of different sub-populations of the two species in the basin.

Mercury and selenium status of bottlenose dolphins ( Tursiops truncatus ): A study in stranded animals on the Canary Islands

“…1A). In accordance with previous authors (Bellante et al, 2012), an increasing trend throughout the life of cetaceans was observed (Fig. 1), probably due to bioaccumulation from the continuous uptake of Hg in the diet and the decreasing ability to excrete this metal and storage in stable forms such as HgSe (Aguilar et al, 1999;Mackey et al, 1995;Wagemann et al, 2000).…”

Mercury concentrations in Atlantic bottlenose dolphins ( Tursiops truncatus ) inhabiting the Indian River Lagoon, Florida: Patterns of spatial and temporal distribution

“…IRL bottlenose dolphins have a long life span, bioaccumulate contaminants and display defined home ranges with a high degree of site fidelity (Mazzoil et al, 2008;Bossart, 2011). Apex predators such as dolphins can serve as indicators of THg contamination (Bellante et al, 2011). As a result of biomagnification through the food chain, tissue concentrations reach the highest levels in species at the top of the food web (Kidd et al, 2011).…”

Trace element concentrations in red swamp crayfish (Procambarus clarkii) and surface sediments in Lake Preola and Gorghi Tondi natural reserve, SW Sicily

“…Because of the toxic effects of some heavy metals, their accumulation through the food web requires constant monitoring in order to apply appropriate and successful mitigation approaches (Bellante et al 2011). Heavy metals from agricultural activities are often discharged into rivers and lakes, and assessing their concentrations has recently become an important component of water pollution monitoring (Canivet et al 2001;Ansaldo et al 2009).…”