Revealing the Current Relationship between Stream Acidification and Fish Species Richness: What is the Status after Two Decades of Recovery in Appalachian Streams?

Track 3C: Gaining Insights from Vertebrate Organisms
Thursday, October 12, 2017, 3:40 pm – 5:10 pm

Christine May
Department of Biology
James Madison University

Prior to limitations on atmospheric emission of sulfur dioxide, Appalachian streams were heavily impacted by acid deposition. Acidification of headwater streams resulted in depletion of acid neutralizing capacity (ANC) and a loss of fish species diversity. Results from a previous study in 1995 indicated a significant relationship between ANC and fish species richness, such that low ANC streams in siliciclastic watersheds support less diversity than relatively higher ANC streams in granitic and basaltic watersheds. Given the potential for acidification recovery in the past two decades, has the relationship between fish species richness and ANC changed? Our research indicates that despite improvements in atmospheric emissions, water chemistry and fish diversity did not improve in all streams. Increases in fish species richness primarily occurred in basaltic watersheds, and the strong correlation (r = 0.94) between fish species richness and ANC observed in 1995 still exists in 2016. Results of this investigation indicate that Appalachian streams are still experiencing legacy effects of past acidification and that a commitment to continued monitoring for recovery trends is vital.