Mercury in Terrestrial Environments: Patterns of Bioaccumulation and Food Web Transfer Along a Forested Elevational Gradient

EPA Grant Number: FP916937
Title: Mercury in Terrestrial Environments: Patterns of Bioaccumulation and Food Web Transfer Along a Forested Elevational Gradient
Investigators: Townsend, Jason Michael
Institution: SUNY College of Environmental Science and Forestry
EPA Project Officer: Michaud, Jayne
Project Period: September 1, 2008 through August 31, 2011
RFA: STAR Graduate Fellowships (2008) RFA Text |  Recipients Lists
Research Category: Academic Fellowships


The purpose of this research is to understand the extent to which mercury and its neurotoxic form, methylmercury, is accumulating in the leaf litter and organisms of terrestrial forests in northeastern North America. The three main objectives of this research are to: 1) identify the food web pathways of mercury transfer and bioaccumulation in each of three forest types arrayed along an elevational gradient: low-elevation deciduous forest, mid-elevation mixed hardwood-coniferous forest, and high-elevation spruce-fir forest; 2) identify the degree to which mercury is methylated and therefore biologically available as a neurotoxin in the leaf-litter of these three focal forest types; 3) in collaboration with other mercury-focused research teams in the Northeast, identify broad-scale terrestrial patterns of biotic mercury accumulation in northeastern North America.


This research will focus on three avian species that will serve as bioindicators of mercury accumulation in each of the three forest types. Bicknell’s Thrush (Catharus bicknelli), Hermit Thrush (C. guttatus) and Veery (C. fuscescens) are strictly terrestrial, insectivorous, song birds. They are similarly sized, are closely related taxonomically, and their geographic ranges overlap. However, their preferred breeding habitats in the Northeast are divided along an elevational gradient. By measuring the three species’ mercury and methylmercury levels within the same watershed, I will be able to compare relative contamination pressures along this elevational gradient. In addition, I will initiate novel investigations into the methylation of leaf litter and into the food web transfer of methylmercury at each site. My research will focus on the Esopus Creek Watershed in the Catskill Mountains of New York, a catchment area encompassing 40% of the drinking water for 9 million people in New York City. This research will also have a strong collaborative component: currently there are ongoing studies of mercury accumulation in Catharus populations of Canada and Vermont, and these will provide valuable data to compare with the findings of this study.

Expected Results:

This study will expand mercury monitoring efforts to terrestrial environments where the patterns of accumulation are poorly understood, and it will identify biological hotspots where contamination risk to humans and wildlife is greatest. This information will help to inform the critical policy debate over the necessity and magnitude of mercury emissions reductions during the coming century.

Supplemental Keywords:

Mercury, Methylmercury, Bioindicator, Biomagnification, Bioaccumulation, Thrushes, Terrestrial Ecology, Upland Forests,

Progress and Final Reports:

  • 2009
  • 2010
  • Final