Reconstruction of sea-land interactions between terrestrial vegetation cover and water quality constituents in the Mattapoisett Harbor area during the 1991 Hurricane Bob event.

Hurricane Bob passed over the New England region in August 1991, causing significant damage to life, property, and the environment, making it one of the costliest hurricanes in New England history. The environmental impact of a hurricane of this magnitude warrants careful assessment to devise preventive measures and mitigation strategies to bolster water resources management programs against future events. In this paper, we show the reconstructed simultaneous impacts of Hurricane Bob on the vegetative cover of the Mattapoisett river watershed and the water quality of the Mattapoisett Harbor with the aid of remote sensing for earth observations. The water quality impacts, especially in terms of Total Organic Carbon (TOC) and Sea Surface Salinity (SSS), can be identified from variations of SSS and TOC near coastal estuaries due to the influx of freshwater from the coastal Mattapoisett River to the continent-ocean transition between natural tides and bay waves. Using the Landsat satellite images, the Normalized Difference Vegetation Index (NDVI) and water quality constitutes (TOC and SSS) were reconstructed and retrieved for the assessment of the sea-land interactions during the Hurricane Bob event in 1991. Results indicate phenomenal interactive patterns between the harbor and the coastal watershed, as well as the riverine system. TOC and NDVI, especially in the upper watershed region, can be strongly correlated with hurricane impacts according to the singular value decomposition analysis.

Meeting report: Methylmercury in marine ecosystems--from sources to seafood consumers.

Mercury and other contaminants in coastal and open-ocean ecosystems are an issue of great concern globally and in the United States, where consumption of marine fish and shellfish is a major route of human exposure to methylmercury (MeHg). A recent National Institute of Environmental Health Sciences-Superfund Basic Research Program workshop titled "Fate and Bioavailability of Mercury in Aquatic Ecosystems and Effects on Human Exposure," convened by the Dartmouth Toxic Metals Research Program on 15-16 November 2006 in Durham, New Hampshire, brought together human health experts, marine scientists, and ecotoxicologists to encourage cross-disciplinary discussion between ecosystem and human health scientists and to articulate research and monitoring priorities to better understand how marine food webs have become contaminated with MeHg. Although human health effects of Hg contamination were a major theme, the workshop also explored effects on marine biota. The workgroup focused on three major topics: a) the biogeochemical cycling of Hg in marine ecosystems, b) the trophic transfer and bioaccumulation of MeHg in marine food webs, and c) human exposure to Hg from marine fish and shellfish consumption. The group concluded that current understanding of Hg in marine ecosystems across a range of habitats, chemical conditions, and ocean basins is severely data limited. An integrated research and monitoring program is needed to link the processes and mechanisms of MeHg production, bioaccumulation, and transfer with MeHg exposure in humans.

Approaches to reducing mercury in North America.

This article provides a summary of the Environmental Protection Agency's role in reducing anthropogenic sources of mercury. These efforts are expected to substantially reduce both mercury releases and exposure. EPA is aware that mercury in the environment is complex and that it must work with programs in other federal agencies, state and local governments that address the mercury problem as well as partner with nongovernmental organizations and industry to reach these goals.

Patterns of mercury deposition and concentration in northeastern North America (1996-2002).

Data from 13 National Atmospheric Deposition Program Mercury Monitor Network (NADP/ MDN) monitoring stations (1996-2002) and the Underhill (VT) event-based monitoring site (1993-2002) were evaluated for spatial and temporal trends. More precipitation and mercury deposition occurred in the southern and coastal MDN sites, except for the Underhill site, which received more mercury deposition than surrounding sites. Precipitation patterns varied. Regionally, higher concentrations of mercury were recorded during the late spring and summer months. Several sub-regional clusters of MDN sites were evident, based on mercury deposition patterns. In general, more mercury was deposited during the summer months. "Enhanced" weekly deposition (> 250 ng/m2) and distinct seasonal deposition patterns were evident at all MDN sites. Regionally, high depositional periods contributed significantly to annual loads (< 20%- approximately 60%). Southern and coastal sites measured more frequent periods of high deposition than inland sites. Spring and summer "enhanced" deposition may be important contributing factors to mercury bioaccumulation during the growing season. Recent regional reductions of mercury emissions were not reflected in the regional mercury concentration or deposition data. Few sites showed linear relations between the concentration of mercury in precipitation and acid rain co-contaminants (sulfates and nitrates).