Monitoring mercury in biota (plants and animals) provides a pathway for understanding spatial gradients, temporal trends, and environmental magnitude of concern that cannot be ascertained in air, water, or sediment. Emphasizing upper trophic level biota for monitoring (i.e., trophic level 4 or higher) ultimately provides a confident ability to assess whether the global input of anthropogenic mercury into the environment is safe or harmful to fish, wildlife and humans. The dual approach presented here suggests conducting biotic mercury monitoring across continents and ocean basins using representative bioindicators. This information can then confidently provide information for decision makers to assess the effectiveness of the Minamata Convention on Mercury at both regional and global spatial levels at temporal scales of interest.