Mercury in cetaceans
International Whaling Commission
This review highlights the continued global exposure and potential effect of mercury on cetaceans. The fate and transportation of this element in the marine environment is driven by anthropogenic atmospheric and aquatic sources as well as through natural geogenic inputs, with coastal areas and species being more vulnerable to mercury contamination than the open ocean.
In a relatively recent review of the research needs related to mercury biogeochemistry, Sonke et al., (2013) concluded “mercury exposure to humans and wildlife are likely to persist unless drastic emission reductions are put in place”. Since then the Minamata Convention (http://www.mercuryconvention.org/) has been ratified by 91 countries and came into force in August 2017. Its provisions include “a ban on new mercury mines, the phasing-out of existing ones, the reduction and eventual cessation of mercury use in many products and processes, control measures on emissions to air and on releases to land and water, and the regulation of the informal sector of artisanal and small-scale gold mining which use mercury in the extraction process”. The aim of the Convention is to control the anthropogenic releases of mercury throughout its lifecycle thereby reducing global emissions and exposure to both wildlife and humans. Continued monitoring of mercury in cetaceans is therefore required to determine whether these new measures reduce the uptake and impact of mercury on cetaceans in future.