Carlsbad Caverns National Park

World Heritage Research

Discover scientific research and academic studies that deepen our understanding of Carlsbad Caverns National Park from its history and significance to its conservation, management, and contemporary challenges.

• Summertime Ozone Production at Carlsbad Caverns National Park, New Mexico: Influence of Oil and Natural Gas Development

  A significant rise in summertime ozone (O₃) levels at Carlsbad Caverns National Park, exceeding 70 ppbv, is linked to the rapid expansion of oil and natural gas (O&G) development in southeastern New Mexico. The study reveals that O₃ production is highly responsive to reductions in both nitrogen oxides (NOₓ) and O&G-related volatile organic compounds (VOCs), with NOₓ reductions proving most effective. Using a constrained F0AM box model, researchers analyzed VOC reactivity and radical budgets, demonstrating that morning O₃ levels are primarily controlled by local photochemistry, while afternoon levels become sensitive to NOₓ loss. A high-O₃ episode was found to be influenced by aged O&G emissions, as indicated by back-trajectory analysis and low i-/n-pentane ratios, suggesting significant nonlocal O₃ formation.

  Marsavin, A., Pan, D., Pollack, I. B., Zhou, Y., Sullivan, A. P., Naimie, L. E., Benedict, K. B., Juncosa Calahoranno, J. F., Fischer, E. V., Prenni, A. J., Schichtel, B. A., Sive, B. C., & Collett, J. L. (2024). Summertime Ozone Production at Carlsbad Caverns National Park, New Mexico: Influence of Oil and Natural Gas Development. Journal of Geophysical Research: Atmospheres, 129(14). Portico. https://doi.org/10.1029/2024jd040877

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• Observations of ozone, acyl peroxy nitrates, and their precursors during summer 2019 at Carlsbad Caverns National Park, New Mexico

  A study at Carlsbad Caverns National Park reveals that ozone (O₃) formation is primarily driven by nitrogen oxides (NOₓ)-sensitive photochemistry, with significant contributions from oil and natural gas (O&G) emissions. During the summer of 2019, elevated O₃ levels exceeding the U.S. air quality standard were observed when winds came from the Permian Basin, a major O&G production region. The research identified that high O₃ days coincided with increased acyl peroxy nitrates, particularly peroxypropionyl nitrate (PPN), indicating dominant influence from anthropogenic volatile organic compounds (VOCs), often alkanes. Positive matrix factorization analysis attributed VOC and NOₓ contributions to primary emissions and secondary photochemical processing. The findings suggest that simultaneous reductions in NOₓ and non-methane VOC emissions from the O&G sector are necessary to effectively lower O₃ levels, with added benefits for reducing other secondary pollutants.

  Pollack, I. B., Pan, D., Marsavin, A., Cope, E. J., Juncosa Calahorrano, J., Naimie, L., Benedict, K. B., Sullivan, A. P., Zhou, Y., Sive, B. C., Prenni, A. J., Schichtel, B. A., Collett, J., & Fischer, E. V. (2023). Observations of ozone, acyl peroxy nitrates, and their precursors during summer 2019 at Carlsbad Caverns National Park, New Mexico. Journal of the Air & Waste Management Association, 73(12), 951–968. https://doi.org/10.1080/10962247.2023.2271436

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• Source characterization of volatile organic compounds at Carlsbad Caverns National Park

  A study identifies oil and gas (O&G) production activities as the major contributors to volatile organic compounds (VOCs) at Carlsbad Caverns National Park, exceeding ground-level ozone limits. Using positive matrix factorization analysis of speciated VOCs during the 2019 Carlsbad Caverns Air Quality Study (CarCavAQS), researchers attributed three factors to O&G operations, with associated residence time analyses indicating increased contributions during transport from the Permian Basin. These O&G-related VOCs accounted for 62% of VOC reactivity with hydroxyl radicals, enhancing local ozone formation. Additionally, photochemically generated secondary VOCs suggested long-range transport of ozone from upwind shale formations like Eagle Ford and Barnett. The findings underscore the critical role of O&G emissions in regional air quality and emphasize the need for targeted emission reductions to mitigate elevated ozone levels.

  Pan, D., Pollack, I. B., Sive, B. C., Marsavin, A., Naimie, L. E., Benedict, K. B., Zhou, Y., Sullivan, A. P., Prenni, A. J., Cope, E. J., Juncosa Calahorrano, J. F., Fischer, E. V., Schichtel, B. A., & Collett, J. L. (2023). Source characterization of volatile organic compounds at Carlsbad Caverns National Park. Journal of the Air & Waste Management Association, 73(12), 914–929. https://doi.org/10.1080/10962247.2023.2266696

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• PM_2.5 in Carlsbad Caverns National Park: Composition, sources, and visibility impacts

  Aerosol composition and sources in Carlsbad Caverns National Park, influenced by oil and gas development, wildfires, urban emissions, and soil dust, significantly impact visibility. The study found that sulfate, soil dust (often reacted with nitric acid), and black carbon are major contributors to light extinction, with the worst visibility periods occurring during transport from the southeast, a region dense with Permian Basin oil and gas development. High-time resolution measurements revealed PM2.5 concentrations up to 31.8 µg/m³, with sulfate and soil dust being primary factors in modeled light extinction. Residence time analysis indicated enrichment of sulfate, black carbon, and methane during transport from the southeast, highlighting the regional influence on air quality.

  Naimie, L. E., Sullivan, A. P., Benedict, K. B., Prenni, A. J., Sive, B. C., Schichtel, B. A., Fischer, E. V., Pollack, I., & Collett, J. (2022). PM_2.5 in Carlsbad Caverns National Park: Composition, sources, and visibility impacts. Journal of the Air & Waste Management Association, 72(11), 1201–1218. https://doi.org/10.1080/10962247.2022.2081634

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• Diversity of siderophore-producing bacterial cultures from Carlsbad Caverns National Park caves, Carlsbad, New Mexico

  Researchers discovered that cave bacteria from Carlsbad Caverns National Park produce siderophores, microbially-produced ferric iron chelators, to survive in nutrient-limited environments. The study identified 64% of bacterial cultures as siderophore producers, with the majority producing hydroxamate-type siderophores. These findings support the hypothesis that siderophores are a critical mechanism for cave bacteria to obtain essential ferric iron. The study used long-term (10–11 years) and short-term (1–3 days) parent cultures inoculated with ferromanganese deposits and carbonate secondary minerals from Lechuguilla and Spider caves, classifying producers using 16S rRNA gene sequencing. Siderophore production was more prevalent in short-term cultures, which also showed a higher proportion of strong producers compared to long-term cultures.

  Duncan, T., Werner-Washburne, M., & Northup, D. (2021). Diversity of siderophore-producing bacterial cultures from Carlsbad Caverns National Park caves, Carlsbad, New Mexico. Journal of Cave and Karst Studies, 83(1), 29–43. https://doi.org/10.4311/2019es0118

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• A Bryophyte Inventory of Carlsbad Caverns National Park

  A bryophyte inventory of Carlsbad Caverns National Park identified 41 species, including 38 mosses and three liverworts, with no hornworts detected. Notably, Riccia atromarginata was documented for the first time in New Mexico, and previously unpublished photographs of Mannia paradoxa, collected in 1982, were shared. Contrary to initial assumptions, seasonally flooded arroyos and north-facing limestone cliffs exhibited higher bryophyte diversity than the park's natural springs, highlighting the importance of these habitats despite water scarcity. The study provides a comprehensive baseline for bryophyte biodiversity in this unique karst landscape.

  Kleinman, R., Blisard, K. S., Allred, K. W., & West, R. (2020). A Bryophyte Inventory of Carlsbad Caverns National Park. Evansia, 37(2), 50. https://doi.org/10.1639/0747-9859-37.2.50

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• Roving with a Digital Visual Library: Increased Learning Opportunities at Carlsbad Caverns National Park

  A pilot program integrating digital visualizations into visitor interpretation at Carlsbad Caverns National Park demonstrated significant potential to enhance science literacy and engagement. Rangers reported that tablet-based presentations of research on Brazilian free-tailed bats improved their ability to achieve interpretive goals, particularly in strategic locations like the cave entrance. Visitors responded positively, though challenges remained, suggesting this blended approach warrants further exploration for broader application in science communication at UNESCO World Heritage Sites.

  Merson, M., Allen, L. C., Cox, P. L., & Hristov, N. I. (2016). Roving with a Digital Visual Library: Increased Learning Opportunities at Carlsbad Caverns National Park. Journal of Interpretation Research, 21(1), 9–28. https://doi.org/10.1177/109258721602100102

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• The Transport of Nonindigenous Microorganisms Into Caves by Human Visitation: A Case Study at Carlsbad Caverns National Park

  A study at Carlsbad Caverns National Park revealed that human visitation significantly impacts the microbial composition of cave environments, introducing nonindigenous microorganisms. Research conducted in 2004 and 2009 demonstrated that Staphylococcus spp., Knoellia spp., Penicillium, Aspergillus, Cladosporium, Alternaria, and Enterobacteriaceae were prevalent in areas frequented by visitors or associated with food storage and consumption. Notably, Enterobacteriaceae dominance was observed along the descent trail and within the Lunch Room, suggesting either natural occurrence or anthropogenic contamination. The study highlights the potential for management practices, such as restricting crumb-generating foods, to mitigate microbial contamination and protect cave ecosystems.

  Griffin, D. W., Gray, M. A., Lyles, M. B., & Northup, D. E. (2014). The Transport of Nonindigenous Microorganisms Into Caves by Human Visitation: A Case Study at Carlsbad Caverns National Park. Geomicrobiology Journal, 31(3), 175–185. https://doi.org/10.1080/01490451.2013.815294

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