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Studies and Monitoring

Acadia National Park

Acadia National Park (NP), Maine, has its own unique environmental concerns based on its particular ecology. Air quality studies and monitoring at Acadia NP focus on acid deposition, mercury, ozone, and visibility. Click on the tabs below to review air quality studies and key scientific references at Acadia NP, as well as to access information on air quality monitoring in the park.

  • Studies & Projects
  • Monitoring & Data
  • Key References

Ongoing research in Acadia NP, Maine:

Assessments of Air Quality at Acadia NP

Air quality monitoring for over 30 years has shown that Acadia NP receives some of the highest levels of air pollution in the northeastern U.S. Potential harm from air pollution to ecosystems, scenic vistas, and public health is one of the most important issues facing the park. The Park Research and Intensive Monitoring of Ecosystems Network (PRIMENet), a long-term monitoring program established in 1996 by the NPS and EPA, investigated air pollution and effects to ecosystems at Acadia NP (and 13 other NPs) (Tonnessen and Manski 2007). PRIMENet and other park assessment programs (e.g. Maniero and Breen 2004; Vaux et al. 2008 [pdf, 11 MB]) produced data and information on air quality condition and trends and ecosystem responses that have been used by various air quality planning groups. more »

Sulfur & Nitrogen Impacts

Long-term sulfur and nitrogen deposition has acidified some streams and a lake in the park (Kahl et al. 1992) and caused high nitrate concentrations in streams (Johnson et al. 2007; Nelson et al. 2008). Deposition exceeds the amount, or critical load, that the ecosystems can tolerate. Nitrogen can also cause nutrient imbalances and loss of biodiversity. The response of aquatic organisms to nitrogen is being examined to identify the critical load at which these natural communities are disrupted. Critical loads can be used to set goals for air quality improvement strategies.

Mercury Impacts

Mercury and other toxic pollutants are elevated in aquatic and terrestrial ecosystems at Acadia NP (Peckenham et al. 2007; Bank et al. 2007a, b; Longcore et al. 2007a, b). Concentrations of mercury in fish from the park exceed statewide freshwater fish consumption thresholds (EPA 2010). Mercury levels in fish also exceed thresholds established for fish-eating wildlife such as loons. Research at two park watersheds indicate landscape variables, e.g., soil pH, vegetation type, and land use history, influence how, and to what extent, mercury accumulates in ecosystems (Johnson et al. 2007). Given these confounding factors, it is difficult to evaluate the full extent of mercury contamination at the park. However, the available evidence on mercury effects in Acadia NP and the Northeastern U.S. prompted the New England Governors and Eastern Canadian Premiers (NEG/ECP) to adopt a comprehensive regional Mercury Action Plan (pdf, 48 KB) with emission reduction and pollution prevention goals for the region, including the long-term goal of eliminating anthropogenic mercury releases in the region (Smith and Trip 2005).

Ground-Level Ozone Impacts

Ground-level ozone at Acadia NP sometimes exceed standards set by the U.S. Environmental Protection Agency to protect public health and vegetation. Surveys in the 1990’s found ozone injury on leaves of spreading dogbane and big-leaf aster plants (Eckert et al. 1997), and ozone has been implicated in the reduced growth of white pine trees (Bartholomay et al. 1997). Controlled exposure experiments have been conducted at the park to identify which species are sensitive to ozone.

Air quality monitoring information and data access:

Air Pollutant/Impact

Monitoring Program

Sites and Data Access

Nitrogen & Sulfur Wet deposition NADP/NTN
Dry deposition CASTNet
Mercury NADP/MDN
Visibility IMPROVE

Abbreviations in the above table:

    CASTNet: EPA Clean Air Status and Trends Network
    GPMP: Gaseous Pollutant Monitoring Program
    IMPROVE: Interagency Monitoring of Protected Visual Environments
    MDN: Mercury Deposition Network
    NADP: National Atmospheric Deposition Program
    NPS: National Park Service
    NTN: National Trends Network
    VIEWS: Visibility Information Exchange Web System

For more information regarding monitoring and data assessments conducted by the National Park Service, link to the NPS Air Quality Monitoring Program or to the NPS Air Quality Monitoring History Database for a history of active and inactive monitoring sites at Acadia NP.

Key air quality related references from Acadia NP, Maine:

Bank, M.S., Burgess, J., Evers, D. and Loftin, C. 2007a. Mercury contamination of biota from Acadia National Park, Maine: a review. Environmental Monitoring and Assessment 126(1–3): 105–115.

Bank, M.S., Crocker, J., Connery, B. and Amirbahman, A. 2007b. Mercury bioaccumulation in green frog (Rana clamitans) and bullfrog (Rana catesbeiana) tadpoles from Acadia National Park, Maine, USA. Environmental Toxicology and Chemistry 26(1): 118–125.

Bartholomay, G.A., Eckert, R.T. and Smith, K.T. 1997. Reductions in tree-ring widths of white pine following ozone exposure at Acadia National Park, Maine, U.S.A. Canadian Journal of Forest Research 27: 361–368.

Dupont, J., Clair, T.A., Gagnon, C., Jeffries, D.S., Kahl, J.S., Nelson, S.J., and Peckenham, J.M. 2005. Estimation of critical loads of acidity for lakes in northeastern United States and eastern Canada. Environmental Monitoring and Assessment. 109: 275–291.

Eckert, R., Kohut, R., Lee, T. and Stapelfeldt, K. 1997. Studies to assess the effects of ozone on native vegetation of Acadia National Park. 1996 Annual Report. University of New Hampshire and Boyce Thompson Institute for Plant Research, Ithaca NY.

[EPA] U.S. Environmental Protection Agency. 2010. 2008 National Listing of Fish Advisories. Available at

Haines, T., Webber, H., and Coyle, J. 2000. An assessment of contaminant threats at Acadia National Park. National Park Service. 74 pp.

Heath, R.H., Kahl, J.S., Norton, S.A. and Brutsaert, W.R. 1993. Elemental mass balances and episodic and ten–year changes in the chemistry of surface water, Acadia National Park, Maine: final report. Technical Report NPS/NAROSS/NRTR—93/16. National Park Service, North Atlantic Region, Boston, Massachusetts. 111 pp.

[IMPROVE] Interagency Monitoring of Protected Visual Environments. 2010. Improve Summary Data. Available at

Jiang, M. and Jagels, R. 1999. Detection and quantification of changes in membrane–associated calcium in red spruce saplings exposed to acid fog. Tree Physiology 19: 909–916.

Johnson, K.B., Haines, T. A., Kahl, J.S., Norton, S.A., Amirbahman, A. and Sheehan, K.D. 2007. Controls on mercury and methylmercury deposition for two watersheds in Acadia National Park, Maine. Environmental Monitoring and Assessment 126: 55–67.

Kahl, J.S., Manski, D., Flora, M. and Houtman, N. 2000. Water Resources Management Plan, Acadia National Park. National Park Service. 103 pp. Available at water/
(pdf, 2.8 MB).

Kahl, J.S., Norton, S.A., Haines, T.A., Rochette, E.A., Heath, R.H. and Nodvin, S.C. 1992. Mechanisms of episodic acidification in low–order streams in Maine, USA. Environmental Pollution 78: 37–44.

Longcore, J.R., Dineli, R. and Haines, T.A. 2007a. Mercury and Growth of Tree Swallows at Acadia National Park, and at Orono, Maine, USA. Environmental Monitoring and Assessment 126 (1–3): 117–127.

Longcore, J.R., Haines, T.A. and Halteman, W.A. 2007b. Mercury in Tree Swallow Food, Eggs, Bodies, and Feathers at Acadia National Park, Maine, and an EPA Superfund Site, Ayer, Massachusetts. Environmental Monitoring and Assessment 126 (1–3): 129–143.

Maniero, T. and Breen, B. 2004. Acadia National Park: Assessment of Long-term Air Quality Programmatic, Monitoring and Research Needs. Natural Resources Report NPS/NER/NRR—2004/002. National Park Service. Boston, MA. Available at

Matz, A.C., Gilbert, J.R., and O’Connell, A.F. 1998. Acadia’s Bald Eagles: research summary and management recommendations. National Park Service. Boston, MA.

[NADP] National Atmospheric Deposition Program. 2007. NTN Data. Available at

Nelson, S.J., Johnson, K.B., Weathers, K.C., Loftin, C.S., Fernandez, I.J., Kahl, J.S. and Krabbenhoft, D.P. 2008. A comparison of winter mercury accumulation at forested and no canopy sites measured with different snow sampling techniques. Applied Geochemistry 23(3): 384–398.

Peckenham, J.M., Kahl, J.S. and Amirbahman, A. 2006. The impact of vehicular traffic on water quality in Acadia National Park. Technical report NPS/NER/NRTR–2006/035. National Park Service, Boston, MA.

Peckenham, J.M., Kahl, J.S., Nelson, S.J., Johnson, K.B. and Haines, T.A. 2007. Landscape Controls on Mercury in Streamwater at Acadia National Park, USA. Environmental Monitoring and Assessment 126(1–3): 97–104.

Smith, C.M. and Trip, L.J. 2005. Mercury Policy and Science in Northeastern North America: The Mercury Action Plan of the New England Governors and Eastern Canadian Premiers. Ecotoxicology 14: 19–35.

Tonnessen, K. and Manski, D. 2007. The Contribution of Acadia PRIMENet Research to Science and Resource Management in the National Park Service. Environ. Monit. Assess. 126: 3–8.

Webber, H.M. and Haines, T. 2003. Mercury effects on predator avoidance behavior of a forage fish, golden shiner (Notemigonus chrysoleucas). Envir. Tox. Chem. 22: 1556–1561.

Weathers, K.C., Simkin, S.M. Lovett, G.M., and Lindberg, S.E. 2006. Empirical modeling of atmospheric deposition in mountainous landscapes. Ecological Applications 16(4): 1590–1607.

Vaux, P.D., Nelson, S.J., Rajakaruna, N., Mittelhauser, G., Bell, K., Kopp, B., Peckenham, J., and Longsworth, G. 2008. Assessment of natural resource conditions in and adjacent to Acadia National Park, Maine. Natural Resource Report NPS/NRPC/WRD/NRR—2008/069. National Park Service, Fort Collins, Colorado. Available at
(pdf, 11 MB).

Featured Content

Impacts icon

Pollutants including sulfur, nitrogen, mercury, ozone, and fine particles affect resources such as forests, streams, wildlife, and scenic vistas. Find out how on our Acadia NP Air Pollution Impacts
web page.

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Last Updated: January 03, 2017