Session Title :

Development of a Global Mercury Observation System toward the preparation of the global mercury treaty (GMOS)

Synopsis :

The anthropogenic release of Hg to terrestrial and aquatic ecosystems and its impact on human health has led to a growing concern of policy makers and scientific community at national and global level. As outcome of past and ongoing national and international programs the need of a Global Mercury Observation System aimed to provide spatial and temporal variations of Hg concentrations in ambient air and precipitation, as well as in the marine and terrestrial ecosystems is considered a top priority for assessing ecosystems response to emission reduction policies.

Description :

The Governing Council of the United Nations Environment Program is developing a global legally binding instrument (or Treaty) on mercury. The intent of this Treaty is to protect human health and the global environment from mercury contamination. Ratification of the Treaty is expected by the majority of the world’s countries in 2013; thereafter an evaluation of the effectiveness of mercury controls will be emphasized. There is a general consensus that to improve our understanding of Hg transport and fate processes in the global environment, there is a need of a continued and concerted international effort to monitor the concentration of Hg species in air, water and biota in both aquatic and terrestrial ecosystems. This would provide data needed for model validation, and for accurate future predictions of changing Hg emissions and ecosystem response at local, regional and global scales. . The GMOS program ( is certainly a relevant European initiative that involves a larger scientific community worldwide that jointly and in cooperation with national and regional programs will allow policy makers and scientists in the near future to fulfil this need. The establishment of a harmonized global monitoring plan that can reflect temporal and spatial changes in environmental mercury loads is the first intermediate objective of GMOS in order to provide the necessary scientific data for determining ecosystem responses. Because there is a non-linear relationship between mercury deposition or releases and subsequent methylation processes and foodweb transfer, upper trophic level biotic endpoints (e.g., predatory fish) are necessary for evaluating the biological fate of mercury. Compliance monitoring will be especially important near major mercury sources, such as artisanal small-scale gold mining areas, coal-fired power facilities, and waste incinerators. Determining best biotic indicators, understanding linkages to major source types, and including sensitive ecosystems will contribute toward developing the most cost-effective approach within the GMOS monitoring program. By developing a harmonized global monitoring plan and being able to track temporal patterns and spatial gradients of concern (e.g., biological mercury hotspots) through field sampling and associated models, countries will have the ability to protect their greatest ecological and human health concerns.