Scientists call for Comprehensive Marine Mercury Monitoring Network

BioDiversity Research Institute, Gorham, ME

Gorham, ME - Four papers - recently released by three leading scientific journals - provide evidence that coastal and marine ecosystems from arctic to tropical regions are sensitive to environmental mercury (Hg) loading. The research findings and associated articles, provided by the BioDiversity Research Institute (BRI), support the need for a comprehensive Marine Mercury Monitoring Network to coordinate international research and monitoring efforts.

BRI and other mercury scientists are working to create comprehensive global mercury monitoring networks. These efforts were summarized yesterday, 6/3/2009, in an article written for Nature and published online (http://www.nature.com/news/2009/090603/full/459620b.html).5 The article frames researchers' challenges within the context of the United Nations Environment Programme (UNEP) treaty to control mercury emissions, which negotiators plan to forge by 2013.

The impetus for the BRI papers arose at the 2006 workshop Fate and Bioavailability of Mercury in Aquatic Systems and Effects on Human Exposure. The workshop was convened by the Dartmouth College Toxic Metals Research Program. It brought together human health experts, marine scientists, and ecotoxicologists to encourage cross-disciplinary discussion between ecosystem and human health scientists. Workshop participants agreed that the current understanding of mercury in marine ecosystems across a range of habitats, chemical conditions, and ocean basins is severely limited.

Although the breadth of Hg research is vast, the linkages between marine sources and ultimate human exposure have not been made across large geographic areas. This is of concern for both human and ecological health. In the U.S., for example, the main vector for methylmercury exposure is consumption of fish and shellfish, 60% of which comes from marine systems.

Methylmercury (MeHg), the toxicologically significant form of mercury, is a known neurotoxin that bioaccumulates and biomagnifies through aquatic food webs. Elevated MeHg levels in fish have resulted in extensive fish-consumption advisories for much of the North American coastline.

In an article that appeared recently in EcoHealth,1 Evers et al. outlined a framework for a Marine Mercury Monitoring Network for temperate and estuarine ecosystems on the Atlantic Coast of North America. The template is applicable to coastal areas across the Northern Hemisphere and is transferable to arctic and tropical marine ecosystems. The priorities for the Network were established at the 2006 Dartmouth workshop; they are the same embraced by the proposed National Mercury Monitoring Program in the U.S.

Within the marine monitoring framework developed by Evers et al., Wing Goodale of the BioDiversity Research Institute (BRI) and fellow researchers across the Gulf of Maine evaluated 604 total mercury (Hg) levels in the eggs and blood of 17 species of marine foraging birds to determine parameters for future biomonitoring in the region. They found that adult blood and eggs are comparable indicators of methyl-mercury bioavailability and eggs,because their relatively easy collection ensures consistent and robust datasets, are the preferred tissue for long-term Hg monitoring. Their results also demonstrated that common eider, Leach's storm petrel,double-crested cormorant, and black guillemot are the most effective bioindicators in the Gulf of Maine.

Research into mercury loading and its potential impact to tropical marine ecosystems has only recently begun. Dr. David Evers (BRI) and colleagues found that 40% of goliath groupers (n=57) sampled in southern Belize exceeded U.S. governmental advisory criteria for human health. The goliath grouper is a common consumer fish, particularly in coastal areas of Belize. This species has also suffered recent range-wide population declines. Potential adverse effects of MeHg loads on goliath grouper include predator avoidance, impaired growth, and lowered reproductive success, warranting further investigation.

"The global reach of anthropogenically-released mercury needs to be monitored through coordinated actions that provide tangible connections between scientists and policy-makers. Marine ecosystems from arctic to tropical regions are contaminated by mercury at levels that are harmful to both human and ecological health. Standardized approaches for monitoring mercury in ecosystems, from air to fish and birds are now available and should be implemented." - Dr. David Evers, BioDiversity Research Institute

Contact Details:

For more information about the 2006 workshop, contact Dr. Celia Chen, Department of Biological Sciences, Dartmouth College, 603-646-2376, Celia.Y.Chen@Dartmouth.Edu

For more information about the proposed Marine Mercury Monitoring Network and tropical mercury studies, contact Dr. David Evers, Executive Director, BioDiversity Research Institute, 207-839-7600 (x110), david.evers@briloon.org

For more information about mercury and seabirds in the Gulf of Maine, contact Wing Goodale, Deputy Director, BioDiversity Research Institute, 207-839-7600 (x109) wing_goodale@briloon.org

Research Articles

  1. Evers et al. (2009) Integrated Mercury Monitoring Program for Temperate Estuarine and Marine Ecosystems on the North American Atlantic Coast. EcoHealth (March 18, 2009) DOI:10.1007/s10393-008-0205-x

  2. Chen et al. (2008) Meeting Report: Methylmercury in Marine Ecosystems-From Sources to Seafood Consumers. Environmental Health Perspectives, 116:1706-1712.

  3. Goodale et al. (2009) Marine Foraging Birds as Bioindicators of Mercury in the Gulf of Maine. EcoHealth (March 10, 2009) DOI:10.1007/s10393-009-0211-7

  4. Evers et al. (2009) Mercury concentrations in the goliath grouper of Belize: an anthropogenic stressor of concern. Endangered Species Research(February 4, 2009) doi:10.3354/esr00158

  5. Lubick, Naomi. (2009) Funding Struggle for Mercury Monitoring: Researchers look to quantify pollution levels. Nature 459, 620-621 Published online June 3, 2009