Aaron Hyatt
Biology Capstone
April 23, 2012
Wiki Two
Integration of Acidic Mining Effects and Resulting Trophic Cascade
Mining has been a staple of the American economy for hundreds of years typically because of
the resource of coal and other raw materials. However until recently the environmental effects haven’t
been well documented and mining has continued to wreak havoc across the U.S. and the globe. This
paper is designed to give a brief but specific dissection and synthesis of coal mining and the way it
manipulates and damages multiple trophic levels of an ecosystem, creating a trophic cascade.
Trophic cascades are usually categorized as bottom-up or top-down cascades in which the
removal or manipulation of certain species among the chain, sets off a reaction that dismantles or
cripples the entire community (Salomon, 2010). Given this information, it is easy to understand how coal
mining and in turn, acidic runoff, is able to complicate food webs and the environment. Coal mining
creates an abiotic filter, specifically soil and water toxicity, in which poisonous metals are released into
the water table, exposing vegetation and organisms that depend on the water (Caruso, 2009). Abiotic
filters, such as toxicity, create a framework in which all biotic interactions and organisms take place;
when the abiotic filter is disturbed, so too is the species existing there. Abiotic factors usually begin with
“low-level” organisms at the base of the food web. Plants and macroinvertebrates are increasingly
receptive to changes in water and soil quality and it is here that a bottom-up trophic cascade will result
(Walsh, 2011).
Acidic mining generally presents a bottom-up cascade because toxins and pollutants that enter
microbial communities and work their way through the trophic levels from the “bottom.” Acidic mining
results in the runoff of toxic chemicals and poisonous metals that leach through surface soils and
watersheds (Wardle, 2005). Plant species assemblages and composition along with macroinvertebrate
population dynamics are generally affected first and often become skewed and disproportionate to their
natural states because certain species will be able to handle increased toxicity levels while others are
less tolerant (Wardle, 2005). These two types of organismal groups are important because they make up
the base of the food chain. As a result of mining, macroinvertebrates and plant species population’s
decrease or change in make-up and the trophic cascade begins to gain real momentum. Zooplankton
consuming fish and herbivores consequently suffer due to a lack of food or change in availability of food.
Predators are generally the last to suffer as a result of the entire food chain collapsing beneath them
(Moon, 2010). A clear example of this can be seen in streams in the Appalachian Mountains. Mining was
a prominent industry in America’s early development and released copious amounts of chemicals into
the environment, poisoning a caddis fly species. The caddis fly was unable to reproduce as protein
channels in the reproductive organ became sterilized from metals in the runoff. The caddis fly
population declined rapidly and its main consumer, the yellow-perch, followed suit and declined
dramatically as a loss of food source was apparent (Moon, 2010). Eventually osprey, fish eating birds,
populations declined as well. The simple release of pollutants into the soil had a devastating effect on
the entire ecosystem not just organism exposed to the toxins, demonstrating just how problematic and
destructive unregulated mining can be.
The idea of trophic cascades is a relatively new idea in the field of biology and can be used to
assess how entire ecosystems will be affected by shifts in soil make up and water quality. Cascades have
already shown effective in restoration with examples like wolf reintroduction in Yellowstone National
Park. The reintroduction of wolves actually increased vegetation cover along stream banks because of
predation on elk and moose populations, a link that would recently have not been put together (Ripple,
2012). Regulating acidic mining to reduce runoff can help us prevent the negative effects felt by coal
mining and effectively end trophic cascades that dismantle ecosystems.
References
Caruso, T., Migliorini, M., Bucci, C., & Bargagli, R. (2009). Spatial patterns and autocorrelation in the
response of microarthropods to soil pollutants: The example of oribatid mites in an abandoned
mining and smelting area. Environmental Pollution, 157(11), 2939-2948.
Moon, D., Moon, J. (2010). Effects of environmental stress cascade up through four trophic levels in a
Salt marsh study system. Ecological Entomology. Vol. 35. P721-726.
Ripple, W., Beschta, R. (2012). Trophic cascades in Yellowstone: The first 15 years after wolf
Reintroduction. Biological Conservation. Vol. 145. P205-213.
Salomon, A., Gaichas, S., et. Al. (2010). Key Features and Context-Dependence of Fishery-Induced
Trophic Cascades. Conservation Biology. Vol. 24. P382-394.
Walsh, J., Dieterle, D., et Al. (2011). Trophic cascades and future harmful algal blooms within ice-free
Arctic Seas north of Bering Strait: A simulation analysis. Progress in Oceanography. Vol. 91.
P312-343.
Wardle, D., Williamson, W., Yeates, G., Bonner, K. (2005) Trickle-down effects of aboveground trophic
Cascades on the soil food web. Oikos. Vol. 111. P348-358.