4f: Science, policy, regulation: Global to local

As the Minamata Convention enters into force and begins to be implemented, Article 22 requires evaluation of the effectiveness of the Convention beginning no later than six years after its entry into force and periodically thereafter at intervals to be decided. At the first Conference of Parties, the parties are tasked with establishing arrangements for providing comparable monitoring data on the presence and movement of mercury in the environment, as well as trends in biotic media and vulnerable populations. Based on analysis of scientific input into existing international environmental agreements, as well as literature on science-policy interactions, we review lessons learned in the area of effectiveness evaluation from scientific assessment processes at global scale. We recommend best practices for the design of assessments and institutions for scientific advice on mercury in the context of the Minamata Convention.

Building on this analysis, we explore how coordinated global-scale metrics might inform Convention decision-making on issues of long-range transport. As mercury poses both local and global pollution challenges, monitoring data reflects influences from a combination of sources, as well as environmental variability and the influence of global climate and other changes. From this perspective, we assess both science-based and policy-driven advantages and disadvantages of upstream metrics such as emissions, and downstream exposure-based measures (e.g. concentrations in biota), at various scales. While upstream metrics are characterized by less uncertainty and variability, downstream metrics are more directly relevant to stakeholder interests. Drawing upon lessons from global ozone and climate negotiations, we propose the development of a new global-scale metric to inform Minamata Convention implementation based on global mean mercury atmospheric concentration. Using an ensemble of simulations with the GEOS-Chem chemical transport model under differing climatic conditions and emission scenarios, we explore the statistical properties of such a metric, and its relationship with upstream and downstream alternatives. In comparison with existing data on atmospheric concentrations, we assess whether the current global monitoring network is sufficient to calculate a global mean concentration metric, and identify areas for improvement. We further assess the robustness of global-scale trends calculated with our metric relative to previous approaches.

For the past twenty-five years Canadas Northern Contaminants Program (NCP) has coordinated research and monitoring on transboundary pollutants in the Canadian North. These pollutants, including mercury, are present at relatively high concentrations in Arctic wildlife that are important food sources for Arctic Indigenous peoples, raising concern for their health and well-being. The primary objectives of the program have therefore been to a) inform and influence the development of policies and regulations that reduce sources of long-range pollutants; and b) provide information to health authorities for the development of public health advice and to Arctic Indigenous people so they can make informed dietary choices. Research and monitoring has addressed questions related to all aspects of contaminant cycling and impacts in northern ecosystems, from long-range sources and transport, to ecosystem and human health risks. Results are routinely published in peer reviewed journals, synthesized and published in comprehensive assessments, and communicated to national and international stakeholders.

Since 2004 the NCP has maintained a contaminant monitoring program that incorporates a variety of abiotic and biotic media that are sampled annually, or in the case of air, continuously, at prescribed locations. A primary objective for the program is to evaluate the effectiveness of international emissions regulations, such as those enshrined in the Minamata Convention. With few exceptions all monitoring is carried out in partnership with Indigenous communities, who in many cases take the lead on all aspects of field sampling. In the case of wildlife monitoring, data from annual sampling carried out since 2004 is augmented by data collected on a periodic basis from the 1990s, and in some cases the 1980s and 1970s. With the adoption of annual monitoring, the statistical power of these timeseries has recently improved to the point where relatively subtle trends are being measured with a reasonable degree of statistical significance.

The influence that global emissions have on mercury levels in wildlife must be assessed in the context of a changing environment. Climate related environmental change in the Arctic can affect all aspects of mercury cycling, including levels in wildlife. It is therefore important that monitoring be complemented by research that provides insights into how environmental processes are being affected by climate change. With the combined knowledge of both research and monitoring, it is possible to draw some conclusions on the relative impact that both changing emissions and a changing climate are having on wildlife exposure and trends.

Mercury (Hg) is a toxic metal classified as a dangerous priority substance to be monitored in aquatic ecosystems by the European Water Framework Directive (WFD), due to its characteristics of bioaccumulation and biomagnification in food webs. An Environmental Quality Standard for biota (EQSbiota) has been defined for Hg in order to classify water bodies and was set at 0.02 mg Hg.kg-1 fresh weight. The application of such a standard requires defining one or more species of fish that is able to integrate the mercury contamination of the river in which they live. For this purpose, the WFD emphasizes the importance to choose species with a high trophic level (TL≥3) which corresponds to fish with the highest Hg concentrations (carnivorous and piscivorous species). Even considering an aquatic environment not exposed to direct inputs of Hg, fish with high trophic level are generally above the EQSbiota.

In French Guiana, we are faced with the difficulty of implementing this standard without downgrading all the aquatic ecosystems. Indeed, this region presents a great contamination of mercury due to the lithology of its soils and its history related to goldmining.

The aim of this study was to help designing appropriate monitoring program of Hg in fish for the implementation of EQS biota in this particular context. A database was created based on the mercury concentrations analyzed in fish muscle during 8 research programs carried out by the University of Bordeaux and the HYDRECO laboratory since 1990. Several difficulties have been encountered, particularly due to the difficulty to identify true reference sites and the high biodiversity of the ichtyofauna (416 known species). Two types of water bodies must be differentiated in French Guiana, due to their distinct hydrographic functioning: creeks (80% of the water system, very little studied) and rivers (20% of the water system). The database counts approximately 3000 fishes distributed over 50 creeks and 6000 fishes caught at about 200 stations located on the rivers of French Guiana; it includes also various information for each fish (Hg concentration in muscle, standard length, weight, family, species, trophic level, sample station location, anthropic or natural pressure for each station, etc.). The first results show that fish species in creeks are different from those present in rivers. After statistical and geographical data processing, 6 to 8 bioindicators species were proposed for creeks and 3 for rivers. The identification of reference sites, however, remains a very delicate task, due to the history associated with goldmining: just 7 potential reference sites for creeks and 4 for rivers. Results on Hg contamination of indicator fish species at reference and contaminated sites will be presented and discussed according to anthropogenic pressure. A first evaluation of reference concentrations is proposed.

Fishing and fish consumption are a vital component of the Anishinaabe bimaadiziwin, or tribal lifeway, of the Ojibwe tribes in the Lake Superior region. The presence of environmental contaminants in fish threatens both the continuation of this lifeway and the exercise of their treaty reserved rights to hunt, fish and gather off-reservation throughout the Ceded Territories in MN, WI, and MI. Here we describe the development of GLIFWCs mercury-based tribal fish consumption advisories which present culturally appropriate advice in the form of lake-specific, color-coded maps. We will also discuss our tribal outreach program for communicating safe fish consumption information, the efficacy of the consumption advisory maps, and the cultural impacts of fish consumption advisories on tribes.

National commitments on the Minamata Convention interact with other global environment and sustainability objectives, such as the Paris Agreement on climate change and the global Sustainable Development Goals. Understanding the interactions between mercury and other policy interventions can help decision-makers identify more effective policies that can address environmental and economic issues simultaneously. Here, we examine: 1) how Chinas national climate policy focused on decarbonization affects the countrys ability to meet its environmental goals related to mercury, and 2) how mercury reductions can contribute to overall national-level sustainability metrics. To address environmental goals, we assess how mercury co-benefits (positive side effects that are peripheral to a policys main goal) of a national climate policy in China could contribute to the countrys commitments under the Minamata Convention on Mercury. We examine climate policy scenarios in 2030 corresponding to various levels of carbon intensity reductions in addition to a business-as-usual scenario. Economic analysis from a computable general equilibrium model of Chinas economy (C-REM) provides information on changes in economic activity resulting from the climate policy scenarios. Using this economic data, we scale 2007 mercury emissions from the Emissions Database for Global Atmospheric Research (EDGAR) in a variety of sectors to 2030. We then use a global atmospheric transport model (GEOS-Chem) to project changes in mercury deposition at the regional scale in China for each policy scenario, and evaluate the resulting spatial distribution of mercury co-benefits. We compare our results to previous literature that considers end-of-pipe controls only for meeting Chinas commitments under the Minamata Convention on Mercury. To address sustainable development goals, we investigate the use of the Inclusive Wealth Index for evaluating the sustainability of climate policy in China on the basis of produced capital, natural capital, and human capital. We discuss the inclusion of mercury impacts in the natural capital and human capital components of the Inclusive Wealth Index by considering cropland, IQ impacts on labor and educational attainment, and other health effects (such as cardiovascular impacts) when data eventually become available.

Fish Hg concentrations well above the Environmental quality standard set by the water framework directive (0.02 mg g-1 ww) are a major concern in large parts of Fennoscandia. Apart from anthropogenic Hg emissions to the atmosphere that deposits to forests far from the source of emissions there are catchment and lake characteristics that make Hg biomagnify effectively in aquatic food chains. Forestry operations can mobilize Hg from the soil, increasing Hg concentrations and loads in surface waters. Forestry activities might also cause waterlogged soils that make good habitats for Hg methylating microorganisms, increasing the formation of bioavailable methylmercury (MeHg). However, available forestry effect studies reveal considerable variation in treatment effects on MeHg at different sites, varying from no effect up to manifold concentration increases. Also, most available forestry effect studies focus on MeHg in low-order streams. When evaluating the effect of forestry on fish Hg concentrations it adds several layers of uncertainty associated with bioaccumulation. For management practices, it is hard to find solutions when the knowledge about different management strategies is complex.

Hg is not originally delivered by forestry itself, but from other human activities as well as natural sources. The forestry sector nevertheless has a responsibility to minimize the negative impact of harvest operations on the forests capacity to buffer and mitigate the pollution originating from other sectors. The issue of climate change has put additional demands on the forests to provide biomass as a substitute for fossil fuel. Thus, decision-makers are facing a wicked problem: How to reduce forestrys impact on Hg in aquatic ecosystems while securing other ecosystem services across the entire forestry cycle.

In order to explore forestrys responsibility and possible solutions to this problem in Sweden, a transdisciplinary approach has been used where actors from relevant governmental agencies, forest companies and forest associations have been involved. Through structured dialogue based in a risk governance approach, the character of the problem and possible ways to handled it were explored. The analysis shows that there are ways to handle the issue, but the complex character of the problem makes a need to include not only management practices for forestry but also the need to discuss regulatory goals and environmental objectives. The Hg-problem represents a class of difficult issues for forestry where the direct impact of forestry needs to be weighed against the contribution which that regulation can have on the overall issue.