The study was published in a recent edition of the journal Applied and Environmental Microbiology and was undertaken in partnership with the Skidaway Institute of Oceanography. The study is part of what has been a 12-year analysis on the recovery of Adirondack lakes from the effects of acid rain funded by the U.S. Environmental Protection Agency's Adirondack Effects Assessment Program (AEAP). The study included bacterial samples from 18 lakes, ponds, and reservoirs in various stages of recovery from acidification in the Adirondack mountain region of New York state.
For the current study, 31 physical and chemical parameters were examined for each water body, ranging from water clarity and temperature to aluminum and hydraulic retention time for a one-year period. Clone "libraries" representing the bacteria were developed from the lake samples and analyzed. The researchers found that the species diversity in acid-impacted Adirondack lakes were similar to bacterial communities in other, non-impacted freshwater systems
The impacts of acidity on most types of bacteria, including the freshwater classes of Actinobacteria and Betaproteobacteria, were found to be indirect, and population levels appeared more directly linked to a combination of acidity along with other environmental factors such as lake depth and carbon content. Several less abundant types of bacteria, including a species known as Alphaproteobacteria, were strongly correlated to acidity and might someday be used as indicators of lake recovery from acidification, according to Nierzwicki-Bauer.
The researchers are in the process of expanding their study to include an additional 13 Adirondack lakes. They also plan to further investigate the role of specific types of bacteria in the ecosystem to better u
|Contact: Gabrielle DeMarco|
Rensselaer Polytechnic Institute