You are here:
Roles of Benthic Algae in the Structure, Function, and Assessment of Stream Ecosystems Affected by Acid Mine Drainage
Citation:
Smucker, Nathan J., S. Drerup, AND M. Vis. Roles of Benthic Algae in the Structure, Function, and Assessment of Stream Ecosystems Affected by Acid Mine Drainage. JOURNAL OF PHYCOLOGY. Allen Press, Inc., Lawrence, KS, 50(3):425-436, (2014).
Impact/Purpose:
Abandoned mine drainage impairs >12,000 km of streams (14% of all stream km) in the Appalachian region of the eastern USA. Here, we synthesize the state of knowledge regarding how AMD-associated stressors affect (1) patterns of algal diversity and their use as ecological indicators, (2) their functional roles in stream ecosystems, and ultimately, (3) how these findings inform management decisions and evaluation of restoration effectiveness. New monitoring approaches, indices of biotic integrity, and metrics based on algal community structure and function effectively assess the severity of AMD and provide valuable insight into the successes or failures of management practices. As a result, measuring the structure and function of algal communities can provide detailed information about the current conditions of AMD-affected streams, inform restoration priorities, decisions, and expectations, and quantify progress toward management goals.
Description:
Tens of thousands of stream kilometers around the world are degraded by a legacy of environmental impacts and acid mine drainage (AMD) caused by abandoned underground and surface mines, piles of discarded coal wastes, and tailings. Increased acidity, high concentrations of metals, and altered habitat negatively affect stream organisms. As the trophic base of primary production in streams, the condition of algal-dominated periphyton communities is particularly important to nutrient cycling, energy flow, and higher trophic levels. Here, we synthesize the state of knowledge regarding how AMD-associated stressors affect (1) patterns of algal diversity and their use as ecological indicators, (2) their functional roles in stream ecosystems, and ultimately, (3) how these findings inform management decisions and evaluation of restoration effectiveness. A growing body of research has found ecological and ecosystem simplification as a result of increasing AMD stressors. Species diversity declines, rates of biomass production decrease, and less efficient uptake and retention of nutrients and carbon occur as AMD severity increases. New monitoring approaches, indices of biotic integrity, and metrics based on algal community structure and function effectively assess the severity of AMD and provide valuable insight into the successes or failures of management practices. Measures of ecosystem processes, such as nutrient uptake rates, extracellular enzyme activities, and metabolism, are increasingly being used as assessment tools, but still remain in their infancy relative to traditional approaches based on community structure. The continued development, testing, and implementation of functional metrics that capture how AMD affects ecosystem processes like these will further advance assessments, restoration efforts, and decision making, especially when used in tandem with metrics based on community structure. Measuring the structure and function of algal communities can provide detailed information about the current conditions of AMD-affected streams, inform restoration priorities, decisions, and expectations, and quantify progress toward management goals.
