Trace metals in striped dolphins (Stenella coeruleoalba) stranded along the Murcia coastline, Mediterranean Sea, during the period 2009-2015

Mercury (Hg), cadmium (Cd), lead (Pb), selenium (Se) and arsenic (As) concentrations in internal tissues of 72 striped dolphins (Stenella coeruleoalba) from Murcia Region (Mediterranean coastline) have been investigated for the first time. Hg showed the highest concentration, followed by Se, Cd, As and Pb. In general, the levels of metal found in this study were similar to those described in similar studies in the Mediterranean Sea. However, in some adult specimens, Hg liver concentrations were related with toxic effects in cetacean. A significant correlation was observed with age, likewise between Se and Hg and Cd in tissues, which agree with detoxify effect attributed to Se through inert complex formation. Molar ratio Hg:Se in liver was close to 1:1 in some specimens, which would indicate overload of the Hg-Se detoxify function and compromised health. These results could contribute to a better knowledge of the distribution of these persistent pollutants in the Mediterranean Sea. (C) 2019 Elsevier Ltd. All rights reserved.