Why Use Loons?
Loons are long lived piscivorous species present across North America. Spatial patterns of biotic Hg levels are increasingly better understood, but still limiting.
For example, in North America, Common Loon (Gavia immer) blood and egg Hg levels demonstrate a significant increase from West to East (Evers et al. 1998, Evers et al. 2003).
This large-scale effort, totaling >3,000 tissue Hg levels serves as the basis for the global loon mercury monitoring research cooperative (GLMMR).
Because of the complexities of Hg deposition, conversion into the toxic methyl form, bioavailability, and differing organismal reactions a landscape-level standardized risk assessment is needed over time. The GLMMR cooperative will greatly contribute to global regulatory interests (UNEP 2003).
GLMMR: Global Loon Mercury Monitoring and Research Cooperative The global atmospheric transport and flux of mercury (Hg) is a dynamic spatio-temporal phenomenon requiring a standardized biomonitoring program. The aim of this working group is to provide an avenue for the implementation of such an essential monitoring program.
Reasons we must monitor mercury:
- Anthropogenic influences on Hg emissions have resulted in substantial increases of biologically available Hg.
- Based on sediment cores, Swain et al. (1992) estimated 3-5x greater Hg deposition than historic, pre-20th century levels.
- Schuster et al. (2002) documented nearly 20x greater deposition records but similar overall temporal signals in glaciers of western U.S.
- Understanding current temporal patterns will guide global policy.
Although regulatory efforts in parts of North American and Europe have dampened emission rates and have subsequently resulted in declining Hg deposition signatures in high-risk areas such as New England (Kamman and Engstrom 2002), new additional contributions to the global Hg atmospheric pool appear to have offset strides in pollution abatement. Increases in methylmercury (MeHg) availability has been measured in arctic seabirds over the past two decades (Braune et al. 2001) including pelagic-foraging petrels (Burgess and Braune 2002), which likely provides insight into the dynamics of today's global Hg pool (because they feed in areas that are not impacted by regional point sources).
Contact
Coordinator: Dr. David Evers
Biodiversity Research Institute
19 Flaggy Meadow rd. Gorham Maine 04038
207-839-7600 ex. 110
