Correlating predictive contaminant deposition maps with streamwater chemistry at Acadia National Park
Acadia National Park is a designated Class I area by federal Clean Air Act regulations. However, it is well documented that the Park receives elevated inputs of atmospheric pollutants that may lead to high concentrations of mercury in fish and contamination of bald eagles by PCBs and dioxin. Continued deposition of nitrogen may result in nitrogen saturation of forests, or contribute to surface water acidification, even with decreases in sulfur emissions due to the Clean Air Act Amendments of 1990. At Acadia, loading of nutrients from upland sources to receiving bodies and estuaries may contribute to eutrophication.
NO2 and SO4 emissions are regulated under current CAAA standards; proposed regulations for mercury emissions have been introduced to Congress in recent years. However, we know little about the delivery and processing of these substances to the terrestrial and aquatic ecosystems, especially at Acadia. In fact, total deposition of the analytes we propose to study has never been quantified for Acadia, despite its Class I status. This integrative approach would provide an estimate of modeled deposition to the park that takes into account the potentially large effects of enhancement due to landscape factors. Further, the approach will, for the first time at this spatial scale, establish whether there is a relationship between what is deposited and surface water chemistry.
This work is part of the long-term watershed research underway to establish watershed mass-balances, or inputs and exports of pollutants and nutrients. The research will benefit from collaboration with the Institute of Ecosystem Studies (IES) in Millbrook, New York. The IES team, headed by Dr. Kathleen Weathers, has studied atmospheric deposition on a park-wide scale. The Mitchell Center team has quantified deposition at a finer scale.
The next logical step in our collaborative research program is to compare the data collected at different spatial scales to see how a general model of contaminant deposition, appropriate for both landscape and watershed scales, can be created. The main objective is twofold: develop a deposition model to provide park management with predictions for the regions and watersheds at greatest risk from high loading of specific contaminants, and thus at risk from ecological effects such as acidification, forest nitrogen saturation, or mercury bioaccumulation, and compare the model results to streamwater chemistry surveys. While we do not propose to investigate mechanisms of processing and transport through the terrestrial ecosystem, the model and its interpretation in conjunction with streamwater chemistry would determine whether there is a disconnect between throughfall flux and deposition and export for some substances.
Annual Report, July-October 2002
Study of Atmospheric Deposition Effects on Surface Waters and Watershed Resources
Paleoecological Assessment of Forest Disturbance in Upper Hadlock Brook and Upper Cadillac Brook Watersheds
Determining Atmospheric Deposition Inputs to Two Small Watersheds at Acadia National Park
Ken Johnson, M.S. Thesis
Just how big is that piece of the puzzle? Quantifying the flux of mercury in forest litter at Acadia National Park