Bolton Landing, N.Y. Prior to the federal Clean Air Act, unhindered industrial emissions were released into the air throughout the Midwestern and Eastern United States for decades. Many of those harmful chemicals came right back down to earth in the form of acid rain, a chemical concoction that includes nitric and sulfuric acid.
Researchers have long known that acid rain can severely decrease the diversity of plant and animal communities in fresh water lakes and ponds. However, little is known about how microscopic bacteria, which form the foundation of freshwater ecosystems, respond to acidification.
To address this knowledge gap, researchers at the Darrin Fresh Water Institute of Rensselaer Polytechnic Institute have developed one of the most comprehensive databases in existence on the impacts of acid rain at the foundation of the biological community.
The team found a general link between increased acidity and decreased bacterial diversity, but surprisingly, most of the dominant species of bacteria were not directly impacted by acidification. However, some rarer types of bacterial populations were significantly or strongly correlated to acidity, rising and falling with fluctuations in water pH. The findings could eventually allow scientists to use these bacteria as indicators of lake recovery, according to Sandra Nierzwicki-Bauer, director of the Darrin Fresh Water Institute and professor of biology.
The research is part of a much broader study on how Adirondack lakes are recovering from the impacts of acidification. "Thanks in large part to the federal Clean Air Act and increased state focus on improving air quality here in New York, we are seeing a number of these lakes on a trajectory to recovery, but up until now we have had little understanding of the changing biodiversity of microbial communities within the impacted lakes as they recover," Nierzwicki-Bauer said. "I hope this study will help other scientists expand
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| Contact: Gabrielle DeMarco demarg@rpi.edu 518-276-6542 Rensselaer Polytechnic Institute Source:Eurekalert |