Assessing Global Environmental Mercury Exposure in Biota and Potential Impacts on Biodiversity

Newswise — Portland, ME – Biodiversity Research Institute (BRI) announces publication of a series of multiyear research studies that assessed the global impact of mercury on air, water, fish, and wildlife in a two-part special issue of Ecotoxicology,an international scientific journal devoted to presenting critical research on the effects of toxic chemicals on populations, communities, and terrestrial, freshwater, and marine ecosystems.

To advance scientific understanding of mercury exposure in biota from around the world, an esteemed group of 193 scientists from more than 30 countries collaborated on producing 19 peer-reviewed papers that form a Special Issue of Ecotoxicology titled Assessing Global Environmental Mercury Exposure in Biota and Potential Impacts on Biodiversity. This broad collection of studies emphasizes mercury exposure in reptiles, fish, birds, and mammals. Other papers further define global sensitivity of mercury in the environment, impacts of mercury to biodiversity, and theories of change that can be used for reducing and eliminating the use of mercury in artisanal small-scale gold mining, which is the largest source of mercury emissions into the environment.

“Understanding the biotic response to methylmercury availability in the environment for all biomes and key biota is vital for evaluating the effectiveness of the Minamata Convention on Mercury,” says David Evers, Ph.D., executive director of BRI.

Evers is one of four guest editors for the special issue that also includes Paco Bustamante, Ph.D., La Rochelle Université; Luis Fernandez, Ph.D., Wake Forest University; and Manoela Pessoa de Miranda, Ph.D., Secretariat of the Minamata Convention on Mercury.

“A comprehensive global analysis of spatiotemporal patterns of mercury exposure and effect to biota requires obtaining and synthesizing critical information from known as well as remote and/or poorly documented areas,” says Bustamante.

The Minamata Convention on Mercury convenes their meeting of the Conference of the Parties in Geneva, Switzerland starting October 30. As part of the Secretariat of the Minamata Convention, Pessoa de Miranda works closely with the leaders of this mercury research effort. “There is a critical need to integrate information,” says Pessoa de Miranda. “The Conference of the Parties to the Minamata Convention made an important decision at its last meeting to work collaboratively and contribute to the Kunming-Montreal Global Biodiversity Framework, adopted under the Convention for Biological Diversity. To make this happen it is essential that we share the current scientific knowledge to as many people as possible. The mercury synthesis in Ecotoxicology is a big step forward in that direction.

Major Findings

• The availability of methylmercury is of concern globally—for every continent and across all oceans and for many lakes and rivers.
• Based on over 2,000 references, mercury body burdens are elevated across all major groups of biota—for fish, reptiles, birds, and mammals.
• Many species of higher trophic level fish and wildlife are exposed to methylmercury concentrations that are of concern by reducing reproductive success and output.
• A meta-analysis demonstrates that more than half of tuna, billfish, and shark species, and over more than half of the fish, seabird, and marine mammal species are adversely impacted by environmental methylmercury loads.
• Because of the large number of individuals, populations, species, and families of biota adversely impacted by methylmercury, biological diversity is likely significantly negatively impacted.
• Models are now available to identify locations in the world where the most sensitive ecosystems overlap with important biodiversity areas. Within those overlap zones, species of greatest concern that are at the highest trophic levels can be identified.
• Spatial analyses of ecosystem sensitivity and of high trophic level species that are regularly consumed by humans can also now be used to conveyed globally to indigenous communities.
• BRI’s Global Biotic Mercury Synthesis (GBMS) dataset provides an important standardized and comprehensive platform for understanding mercury concentrations at spatial and temporal scales that are important for biomonitoring interests of Parties and the Minamata Convention.

“The overall findings of this synthesis make it clear that the rate of loss of biodiversity is increasing, and we are deeply concerned that in tropical forests the damage from artisanal gold mining will reach a point of no return,” says Fernandez.