MercNet: a national monitoring network to assess responses to changing mercury emissions in the United States

Abstract

A partnership of federal and state agencies, tribes, industry, and scientists from academic research and environmental organizations is establishing a national, policy-relevant mercury monitoring network, called MercNet, to address key questions concerning changes in anthropogenic mercury emissions and deposition, associated linkages to ecosystem effects, and recovery from mercury contamination. This network would quantify mercury in the atmosphere, land, water, and biota in terrestrial, freshwater, and coastal ecosystems to provide a national scientific capability for evaluating the benefits and effectiveness of emission controls. Program development began with two workshops, convened to establish network goals, to select key indicators for monitoring, to propose a geographic network of monitoring sites, and to design a monitoring plan. MercNet relies strongly on multi-institutional partnerships to secure the capabilities and comprehensive data that are needed to develop, calibrate, and refine predictive mercury models and to guide effective management. Ongoing collaborative efforts include the: (1) development of regional multi-media databases on mercury in the Laurentian Great Lakes, northeastern United States, and eastern Canada; (2) syntheses and reporting of these data for the scientific and policy communities; and (3) evaluation of potential monitoring sites. The MercNet approach could be applied to the development of other monitoring programs, such as emerging efforts to monitor and assess global mercury emission controls.

Soil mercury and its response to atmospheric mercury deposition across the northeastern United States

“…Higher atmospheric Hg deposition and soil Hg concentrations and pools were found in the ADR and the CATPOC regions. These two subregions likely receive higher atmospheric Hg deposition due to their closer proximity to elevated Hg emission sources in the Midwest and urban centers of the Northeast (Choi et al 2008, Schmeltz et al 2011 and their relatively higher elevations (Yu et al 2011). The lack of significant correlations between current atmospheric Hg deposition and soil Hg concentrations and pools has been reported in previous investigations (Obrist et al 2011).…”

“…The historical record obtained from paleolimnological studies suggests that atmospheric Hg deposition has increased steadily (two-to three-fold) since the onset of industrialization until the late 1900s (Swain et al 1992, Fitzgerald et al 1998, Lorey and Driscoll 1999, Schuster et al 2002, Biester et al 2007). Studies have also indicated that regional Hg deposition has decreased in recent decades, which is coincident with efforts to control Hg emissions in North America (Engstrom and Swain 1997, Drevnick et al 2011, Schmeltz et al 2011. Studies suggest that Hg deposition Notes: The deposition before industrialization (,1850) was considered to be steadfast at each of the subregions.…”

Spatial gradients of methylmercury for breeding common loons in the Laurentian Great Lakes region

“…Widespread, and often elevated, biological Hg exposure implies the need for Hg monitoring at a regional and national scale that can track changes in Hg emissions and effluents. Long-term Hg monitoring across the Great Lakes region by the Mercury Deposition Network needs to be supplemented with components as described in the proposed National Mercury Monitoring Program or MercNet (Mason et al 2005;Harris et al 2007;USEPA 2008;Schmeltz et al 2011). Such a standardized network is necessary to inform federal and state Hg-related policies, provide data for predictive models, and characterize the biological effects in the United States from the redistribution of anthropogenic Hg on the landscape.…”

High levels of maternally transferred mercury disrupt magnetic responses of snapping turtle hatchlings (Chelydra serpentina)

“…Mercury (Hg) is a highly toxic pollutant released from anthropogenic sources such as waste from chemical plants and emissions from coal burning power plants (Scheuhammer et al, 2007;Schmeltz et al, 2011;Walker, 2014). In aquatic habitats mercury is methylated into methylmercury (MeHg), which increases its toxicity (Lindqvist et al, 1991;Bloom, 1992).…”