DENITRIFIER DIVERSITY IN AN ECOSYSTEM IMPACTED BY ACID MINE DRAINAGE

An estimated 23,000 abandoned mines are scattered across the State of Colorado. These abandoned mines often leak effluent that is low in pH and high in dissolved metals. This acid mine drainage (AMD) adversely affects terrestrial and aquatic ecosystems. However, little is known about microbial community structures within most AMD-impacted systems. Additionally, far less is known about denitrifying microorganisms in these same systems, despite their critical role in mitigating nitrogen pollution. Denitrifying microorganisms are capable of removing external nitrogen that could otherwise lead to problems such as reduced drinking water quality, toxic effects on freshwater biota, and disruption of aquatic nutrient cycling. In this study, denitrifier diversity and community structure are assessed in relation to the environmental variables found within the Iron Springs Mining District of Southwestern Colorado. This study provides new insight into the biogeochemical potential of ecosystems affected by AMD and may influence future remediation and watershed management decisions.