This report establishes a baseline inventory of microorganisms in acidic hot springs of Yellowstone National Park (YNP). The analysis is based on observations carried out over the past 25 years using light microscopy, DNA staining, and electron microscopy of environmental samples. The inventory, while incomplete in that not all organisms have been cultured or examined using genetic approaches, represents a study of several solfatara (acid sulfate) geyser basins in YNP. We found that the types of microorganisms in flowing springs had changed over time. In contrast, no such changes occurred in mixing pools. We solicited opinions of prominent YNP microbiologists to address the issue of change in the context of human cross-contamination of springs and to suggest sampling protocols. While the consensus is that research has not introduced exotic species, this explanation is always uncertain. The issues related to this uncertainty, including human cross-contamination, are discussed, and sampling methods designed to best preserve the springs for future investigations are described.
Lindstrom, Robert F.; Ramaley, Robert F.; and Weiss Bizzoco, Richard L.
"Invisible invasion: potential contamination of Yellowstone hot springs by human activity,"
Western North American Naturalist: Vol. 62
, Article 6.
Available at: http://scholarsarchive.byu.edu/wnan/vol62/iss1/6