Park Air Profiles - Acadia National Park

A park visitor and her dog enjoy the fall colors at Jordan Pond in Acadia National Park
Visitors to Acadia NP, Maine, enjoy crisp clear air and scenic views.

Photo courtesy of Jesse Rosenwald

Air quality at Acadia National Park

Most visitors expect clean air and good visibility in parks. However, Acadia National Park (NP), Maine, is downwind from large urban and industrial areas in the states to the south and west. Polluted air coming from these areas is trapped by the park’s steep slopes and high peaks. Over 30 years of air quality monitoring has shown that Acadia NP receives some of the highest levels of pollution in the northeastern U.S. Air pollution can harm ecosystems, scenic vistas, and public health. This is one of the most important environmental issues facing the park. The National Park Service works to address air pollution effects at Acadia NP, and in parks across the U.S., through science, policy and planning, and by doing our part.

Nitrogen and sulfur

Nitrogen and sulfur compounds deposited from the air may have harmful effects, including acidification, on soils, lakes, ponds, and streams. Surface waters and vegetation on the park's high peaks and steep slopes with shallow soils and resistant bedrock that is unable to buffer excess acids are particularly sensitive. Some plants are sensitive to acidification, search for acid-sensitive plant species found at Acadia NP.

Excess nitrogen can also lead to nutrient enrichment, a process that changes nutrient cycling and alters plant communities. Healthy ecosystems can naturally buffer a certain amount of pollution, but as nitrogen and sulfur accumulate, a threshold is passed where the ecosystem is harmed. “Critical load” is a term used to describe the amount of pollution above which harmful changes in sensitive ecosystems occur (Porter 2005). Nitrogen deposition exceeds the critical load for one or more park ecosystems (NPS ARD 2018).

Nitrogen and sulfur effects:

  • Annual average precipitation is 3 times more acidic than unpolluted rain. Measured pH ranges from 4.8 to 5.2 (NADP 2018)
  • Decline in red spruce at sites with both acid fog and acid rain (Jiang and Jagels 1999)
  • Episodic acidification in park streams following precipitation events, with pH values as low as 4.7 (Kahl et al. 1992; Heath et al. 1993)
  • Chronic acidification of Sargent Mountain Pond (Kahl et al 2000)
  • 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)
  • Elevated nitrate concentrations in some park streams (Johnson et al. 2007; Nelson et al. 2008) suggests that forest soils are saturated with nitrogen (Vaux et al. 2008)

Visit the NPS air quality conditions and trends website for park-specific nitrogen and sulfur deposition information. Acadia National Park has been monitoring atmospheric deposition of nitrogen and sulfur since 1981. Explore air monitoring »

Mercury and toxics

A loon on Echo Lake in Acadia NP A loon on Echo Lake at Acadia NP, Maine.

Airborne mercury and other toxic air contaminants are known to harm birds, salamanders, fish, and other wildlife and cause human health concerns. These substances are deposited in park ecosystems, where they enter the food chain and accumulate in the tissue of organisms. This can cause reduced reproductive success, impaired growth and development, and decreased survival for park wildlife.

Mercury and air toxics effects:

  • Mercury and other toxic air 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)
  • Mercury concentrations are elevated in park wildlife from all levels of the food chain, including fish, salamanders, tadpoles, loons, bald eagles, river otter, and mink (Bank et al. 2007a, b)
  • Tree swallow chicks with higher mercury concentrations have slower growth rates (Longcore et al. 2007a, b)
  • Certain fish (golden shiners) have increased vulnerability to predation associated with higher levels of mercury in park waters (Webber and Haines 2003)
  • Concentrations of mercury in fish from the park exceed statewide freshwater fish consumption thresholds (EPA 2010)
  • Levels of mercury in fish exceed safe consumption thresholds for humans and fish-eating wildlife such as loons (Haines et al. 2000)
  • Elevated concentrations of organochlorine contaminants like DDT in bald eagles may be affecting eagle reproduction in the park (Matz et al. 1998)
  • Park streams and springs contain elevated levels of trace metals associated with vehicle exhaust. These metals include aluminium, zinc, copper, molybdenum, and arsenic (Peckenham et al. 2006)

Research at two Acadia NP watersheds indicate that landscape variables including soil pH, vegetation type, and land use history, influence how, and to what extend, mercury accumulates in ecosystems (Johnson et al. 2007).

The New England Governors and Eastern Canadian Premiers (NEG/ECP) are addressing regional mercury concerns through a comprehensive Mercury Action Plan with emission reduction and pollution prevention goals (Smith and Trip 2005).

Acadia National Park has been monitoring mercury since 1996. Explore air monitoring »

Chokecherry plant (Prunus virginiana)
Chokecherry is one of the ozone sensitive species found at Acadia NP, Maine.

Ground-level ozone

At ground level, ozone is harmful to human health and the environment. Ground-level ozone does not come directly from smokestacks or vehicles, but instead is formed when other pollutants, mainly nitrogen oxides and volatile organic compounds, react in the presence of sunlight.

Over the course of a growing season, ozone can damage plant tissues making it harder for plants to produce and store food. It also weakens plants making them less resistant to disease and insect infestations. Some plants are more sensitive to ozone than others. Search ozone-sensitive plant species found at Acadia.

Ozone effects on vegetation:
  • Dogbane and big-leaf aster plants are showing signs of ozone injury (Eckert et al. 1997)
  • White pines experience reduced growth, as measured by tree rings (Bartholomay et al. 1997)
  • Ground-level ozone at Acadia NP sometimes exceeds standards set by the U.S. Environmental Protection Agency (EPA) to protect public health and vegetation
Visit the NPS air quality conditions and trends website for park-specific ozone information. Acadia National Park has been monitoring ozone since 1995. Check out the live ozone and meteorology data from Acadia, NP and explore air monitoring »

Visibility

Rocky ocean drive coast in Acadia NP Clean, clear air is essential to appreciating the rocky coastal views at Acadia NP, Maine.
Park vistas are often obscured by haze, reducing how well and how far people can see. Visibility reducing haze is caused by tiny particles in the air, and these particles can also affect human health. Many of the same pollutants that ultimately fall out as nitrogen and sulfur deposition contribute to this haze. Organic compounds, soot, and dust reduce visibility as well.

Visibility effects:
  • Reduction of the average natural visual range from about 110 miles (without the effects of pollution) to about 90 miles because of pollution at the park
  • Reduction of the visual range from about 70 miles to below 50 miles on high pollution days;
  • Human-caused haze frequently impairs scenic vistas at the park
Visit the NPS air quality conditions and trends website for park-specific visibility information. Explore scenic vistas through a live webcam at Acadia National Park.

Acadia National Park has been monitoring visibility since 1998. Explore air monitoring »

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 https://www.epa.gov/fish-tech

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.

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.

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.

Kohut R.J. 2007. Ozone Risk Assessment for Vital Signs Monitoring Networks, Appalachian National Scenic Trail, and Natchez Trace National Scenic Trail. NPS/NRPC/ARD/NRTR—2007/001. National Park Service. Fort Collins, Colorado. Available at https://www.nps.gov/articles/ozone-risk-assessment.htm

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 https://irma.nps.gov/DataStore/Reference/Profile/2179421

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. 2018. NTN Data. Accessed May 24 2018. Available at http://nadp.slh.wisc.edu/NADP/

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.

Porter, E., Blett, T., Potter, D.U., Huber, C. 2005. Protecting resources on federal lands: Implications of critical loads for atmospheric deposition of nitrogen and sulfur. BioScience 55(7): 603–612. https://doi.org/10.1641/0006-3568(2005)055[0603:PROFLI]2.0.CO;2

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.

Sullivan T.J. 2016. Air quality related values (AQRVs) in national parks: Effects from ozone; visibility reducing particles; and atmospheric deposition of acids, nutrients and toxics. Natural Resource Report. NPS/NRSS/ARD/NRR—2016/1196. National Park Service. Fort Collins, Colorado. Available at https://www.nps.gov/articles/aqrv-assessment.htm

Sullivan, T. J., McDonnell, T. C., McPherson, G. T., Mackey, S. D., Moore, D. 2011a. Evaluation of the sensitivity of inventory and monitoring national parks to nutrient enrichment effects from atmospheric nitrogen deposition: main report. Natural Resource Report NPS/NRPC/ARD/NRR—2011/313. National Park Service, Denver, Colorado. Available at https://www.nps.gov/articles/nitrogen-risk-assessment.htm

Sullivan, T. J., McDonnell, T. C., McPherson, G. T., Mackey, S. D., Moore, D. 2011b. Evaluation of the sensitivity of inventory and monitoring national parks to nutrient enrichment effects from atmospheric nitrogen deposition: Northeast Temperate Network (NETN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/330. National Park Service, Denver, Colorado. Available at https://irma.nps.gov/DataStore/Reference/Profile/2168712

Sullivan, T. J., McPherson, G. T., McDonnell, T. C., Mackey, S. D., Moore, D. 2011c. Evaluation of the sensitivity of inventory and monitoring national parks to acidification effects from atmospheric sulfur and nitrogen deposition: main report. Natural Resource Report NPS/NRPC/ARD/NRR—2011/349. National Park Service, Denver, Colorado. Available at https://www.nps.gov/articles/acidification-risk-assessment.htm

Sullivan, T. J., McPherson, G. T., McDonnell, T. C., Mackey, S. D., Moore, D. 2011d. Evaluation of the sensitivity of inventory and monitoring national parks to acidification effects from atmospheric sulfur and nitrogen deposition: Northeast Temperate Network (NETN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/360. National Park Service, Denver, Colorado. Available at https://irma.nps.gov/DataStore/Reference/Profile/2170596

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 https://irma.nps.gov/DataStore/Reference/Profile/2179608

Last updated: July 24, 2018