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Diatom Communities near Acid Mine Drainage at Green Valley Lake, West Terre
Haute, Indiana
BRINKMANN, S.A., BRAKE, S.S, & STONE, J.R.
Earth and Environmental Systems
Indiana State University, Terre Haute, IN 47809
Abstract
Methods
Collecting
Green Valley Lake is located in West Terre Haute, Indiana, near an abandoned
coal mine. Acid Mine Drainage (AMD) leaching from the site of the abandoned mine has
impacted this area for almost 55 years. Seasonally, the pH of effluent streams drops as low
as 3 in some areas. Elevated levels of SO4, Fe, Al, and heavy metals occur in streams (and
groundwater) that may contaminate Green Valley Lake.
Diatoms are a golden-brown algae with a siliceous skeleton; they are an important
primary producers that are abundant and typically well-preserved as fossils in most lake
systems. To explore the environmental impact of AMD on this system, we sampled the lake
plankton and sediments for fossil diatoms, which are known to be highly sensitive to acidity in
lakes and streams. The purpose of this study is to analyze the spatial distribution of diatoms
in the lake and sediments. Samples were collected from the plankton and sediment from 11
locations around the lake. Our hypothesis is that diatom diversity should increase away from
areas of riverine discharge into the lake. Results from this study will help determine how AMD
has influenced the structure of the diatom community in the lake and provide a baseline
measurement for the modern lake system so that the long-term resilience of these
communities can be analyzed in future studies.
Background
SITE
The reclaimed Green Valley mine site, located in West Terre Haute, Indiana,
contains over five million tons of waste material (Brake, Hasiotis & Dannelly, 2004). After site
abandonment in 1963, levees surrounding ponds were breached by erosion, leading to
uncontrolled movement of contamination from the mine area. Acid mine drainage (AMD)
associated with the mine site most likely seeps into Green Valley Lake, via groundwater. AMD
forms when sulfide-bearing minerals, such as pyrite, react with the atmosphere and
waterways and produce iron- and aluminum- rich sulfuric acid solutions. These solutions
contain elevated concentrations of total dissolved solids, iron, aluminum and sulphate.
Diatom distribution is influenced by seasonal and intraseasonal changes in water
temperature and chemistry, Diatoms are absent in winter due to cool water temperatures. In
summer, isolated communities are present due to warmer water temperatures. When this
leaching enters natural stream systems, acidity and high concentrations of dissolved
constituents can adversely impact aquatic life (Brake, Hasiotis & Dannelly, 2004).
RESEARCH
Soluble reactive phosphorus, typically in the form of orthophosphate (PO43-), can
be a nutrient for aquatic macrophytes and algae. Because phosphorus is typically a limiting
nutrient, the presence of differing levels of phosphorus can alter the aquatic community,
resulting in a change in the dominant phytoplankton. In lake systems with excessive
phosphorus, this may cause health risks or become an aesthetic nuisance to those living near
or using the waterways, because high levels of phosphorus may produce cyanobacteria
blooms (Wetzel, 2001).
Because diatoms are minute and virtually ubiquitous (often occurring in tap water, for example), and
their frustules (shells) are resistant to decay, it is very easy to contaminate samples with either living or dead
diatoms from elsewhere. Extreme cleanliness was therefore required during sampling. Procedures were followed
that prevent contamination from such sources (use of reverse osmosis pure water, for example).
Two types of samples were taken: planktonic and benthic. Samples were collected from a rowboat that
was anchored at intervals through the lake. At each interval a scoop was sent to the lake floor, along with a
measuring device. Planktonic samples were taken using a plankton net, which collects water from the top part of
the water and contains anything floating within it. Site coordinates and depth were recorded for each location. The
sample locations transect away from the AMD creek input, and around the lake perimeter. The samples were
labeled numerically, each site consisted of a sample “A” and “B” representing planktonic and benthic, respectively.
Processing
It is necessary to remove any organic matter from diatom samples in order to make microscopic
identification efficient. The cleaning process also allows unwanted mineral material to be removed and the
concentration of diatoms to be adjusted. Since hydrogen peroxide is a powerful oxidizing agent, precautions must
be taken to prevent contact with the skin and eyes.
Samples are transferred into scintillation vials, where hydrogen peroxide is added and left until all
organic material has been removed (this may take several days). Following the processing stage, the samples are
put through a water bath, and samples were filled with RO pure water, then were left to settle out overnight
between each wash or by centrifugation; this rinsing stage is repeated at least 3 times.
The goal is to produce an even spread of diatoms over the cover slip. This process begins by gently
heating the coverslips after the diatoms have been allowed to settle. Using pipettes, up to 0.5ml of well mixed
diatom suspension is placed on each cover slip, which are then covered to keep off dust. These are left to dry on a
heated table. A hotplate is then heated up to 130oC, and 1 drop of Naphrax is placed on a glass slide to drive off
the toluene in the Naphrax.
Results
Background (Continued)
Acidity, iron, and aluminum all play a role in the fate of phosphorus in aquatic systems; phosphorus is soluble at
low pH, but tends to bind to aluminum and iron, particularly when it is in an oxidized state (ferric iron). Ferric iron particulate
matter often dissolves in the bottom waters of most lakes as the lack of oxygen in the water transforms it into a reduced state
(ferrous iron), which is soluble in water. In temperate lake systems, where iron and aluminum are present, phosphorus is often
transported when it is bound to particulate matter falls through the water column and into the sediment. Under anoxic
conditions, it is released and tends to be stored in the colder and denser water layers until mixing events carry it into the
surface waters, where it is once again accessible to aquatic plants and algae as soluble reactive phosphorus (Wetzel, 2001).
As pH in a lake or stream decreases, aluminum levels increase. In high abundances, aluminum and acid can cause chronic
stress, disrupt food webs, and decrease biodiversity for aquatic organisms. Some types of organisms are able to tolerate acidic
waters, while others may be acid-sensitive, this change in tolerance is represented in Green Valley lake by presence of
Cyclotella meneghiniana and Stephanodiscus ("Effects of acid," 2012).
By looking at a Google image of the Green Valley lake area, algal blooms are seen along the northern shore of the
pond. This is a response to increased levels of nutrients, a likely cause of this is the farmland that surrounds this basin;
farmland is commonly fertilized with nitrogen and phosphorus. Hypertrophication is the ecosystems response to addition of
artificial or natural substances such as nitrates and phosphates, through fertilizers or sewage to an aquatic system (Schindler
& Vallentyne, 2004). Enhanced growth of aquatic vegetation or phytoplankton and algal blooms disrupts normal functioning of
the ecosystem (Bartram, 1999).
The combined addition of Fe, Al, and acidic water to the lake system suggests that there is a strong potential for
these components to disrupt the "normal" lake cycling of phosphorus. Acid mine drainage entering the lake system through
groundwater may result in a change in the water chemistry, binding phosphorus temporarily and storing it in the cold dense
bottom waters, until lake mixing releases it.
General chemical and physical conditions which currently exist at Green Valley Lake are set forth
in the section titled “Graphs”. The presence of Cyclotella and Stephanodiscus diatom genera is useful in this
study to understand low nutrient (low phosphorous levels) and high nutrient (high phosphorous levels) systems
in Green Valley Lake. The main purpose of this method is treating the data as a whole that way diatom
community structure is highlighted and the information is condensed in a simple and interpretable way. The
data matrix consisted of samples from 11 sites, one set labeled “A” representing samples from the water
column, and one set labeled “B” representing benthic material. Dominant planktonic taxa included Fragilaria,
Asterionella (highest abundance at site 6), Cyclotella, Stephanodiscus (relatively abundant throughout sites),
and Synedra (highest abundance at site 3). Dominant benthic taxa included Fragilaria, Nitzschia (similar
abundances in all samples except 5 and 8), Cyclotella, and Stephanodiscus (with their abundances peaking
around sites 5 and 9). Diatom distribution in the sediment reveals a continuous increase of Cyclotella and
Stephanodiscus towards the center of Green Valley lake, and a gradual decrease towards the edges of the
pond, with the exception of sites nine and ten which are nearest high-nutrient input. The association of
diatoms reflects the overall ecological conditions of the water body, it is not always possible to correlate the
water quality of a particular area expressed by the diatom association with a chemical analysis of the water
samples taken at the same time (Patrick, 1968).
The measured pH of the lake water (2013) varied between 8.5-9.0. About 200 diatom frustules
were counted from each planktonic and benthic sample site. Representations of Green Valley Lake surface
temperatures (°C), surface electrical conductivity (µS), and bathymetry based on depths from each site (ft.).
The pie charts surrounding the sample map indicate the relative abundances of planktonic samples (purple
and blue charts) and benthic samples (yellow and red charts); it is important to note that it’s the samples (not
the genera) that are planktonic/benthic. For simplicity, the genera Epithemia, Cocconeis, Karayevia, Nitzschia,
Placoneis, Hantzschia, Eunotia, Achnanthes, Gomphonema, Psammothidium, Cymatopleura, and Navicula
have been lumped together as “Benthic ” for the samples from the water column.
Graphs
Surface Temperatures
Menoghin
iana
4%
Asteroinella
10%
Cymbella
2%
Menoghinian
a
3%
Lake Conductivity
Nitzschia
14%
5%
Fragilaria
30%
15%
Synedra
2%
Fragilaria
48%
18%
24%
11%
4%
15%
4%
17%
12%
2%
4%
2%
4%
31%
14%
2%
1%
26%
23%
References
14%
44%
3%
12%
11%
4%
36%
4%
2%
2%
1%
(n.d) Phosphorous control in water and wastewater. General Chemical, Technical Bulletin:(Wastewater), Retrieved
from http://www.generalchemical.com/assets/pdf/Phosphorus_Control_in_Water_and_Wastewater.pdf
4%
Turner B.L et al. (2003) Organic phosphorus in the environment. CABI publishing
7%
6%
1% 5%
25%
9%
1%
17%
13% 15%
1%
3% 2%
13%
34%
2%
17%
44%
7%
5%
13%
2%
52%
4%
2%
29%
2%
7%
22%
34%
13%
2%
2% 5%
26%
4%
6%
17%
7%
13%
14%
15%
10%
6%
18%
10%
3%
3%
14%
25%
21%
Cyclotella
15%
4%
23%
24%
Discostell
a
1%
8%
1%
1%
Benthic
22%
Synedra
Stephano
Benthic; 28% 6%
discus
12%
Discostella
0%
Stephanodisc
us
0%
Cyclotella
3%
Bathymetry
Likewise for the “Benthic” genera, Epithemia, Encyonema, Cymatopleura,
Cocconeis, Epithemiales, Karayevia, Eunotia, Gomphonema, Placoneis, and
Achnanthes are grouped together for the samples from the sediment.
Diatoms react to the sum of total stresses, pollutant(s) may have a more
sever effect if other environmental conditions produce stress than if this
does not occur. As shown by Patrick (1968), that when the pH of the water
of a diatom community, which typically lived in a mean of 7.56, was lowered
to a mean pH of 5.3 in May/June when the day length and temperature
were favorable for diatom growth. This lowering of pH did not cause a severe
shift in the number and relative abundance of the species present. From
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accompanied by other environmental stresses. The ability for species of
diatoms to live under conditions of concentrated organic pollutants may be
because they can utilize the nutrients that are present such as amino acids
and other organic forms of nitrogen; in other cases, it may be because they
are able to enclose the excessive concentration of heavy metals in a
vacuole or to change their chemical rate so that they do not interfere with
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can flourish in the presence of heavy metals include Stephanodiscus,
Achnanthes, Eunotia, and Synedra; Nitzschia being an excellent indicator of
increased nutrients in a body of water.
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benthic samples. These species are all benthic, even though they have been
found in the plankton.
1%
10%
13%
18%
42%
32%
10%
17%
6%
18%
25%
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wisconsin lakes. (U.S. Geological Survey, University of Texas-Dalls, Richardson)
24%
7%
12%
38%
10%
35%
6%
1%
9%
16%
11%
5%
5%
12% 11%
14%
8%
32%
13%
16%
13%
Carritt, D.E. and S. Goodall. 1954. Sorption reactions and some ecological implications. Deep-sea Res. I:224-243
2%
23%
Stumm, W., and J.J. Morgan. 1970. Aquatic chemistry. Wiley-Interscience.
4%
17%
4%
Wetzel (2001) Limnology: Lake and River Ecosystems (3rd Edition), Academic Press, 1006 pages.
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http://www.epa.gov/acidrain/effects/surface_water.html
7%
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in: Toxic Cyanobacteria in Water: A guide to their public health consequences, monitoring and management. World
Health Organization. URL: WHO document (http://www.who.int
/water_sanitation_health/resourcesquality/toxicyanbact/en/)
15%
23%
2% 2%
2% 6%
2%
56%
1%
1%
30%
6%
47%
3%
4%
9%
13%
2%
14%
14%
Carpenter, S.R., N.F. Caraco, and V.H. Smith. 1998. Nonpoint pollution of surface waters with phosphorus and
nitrogen. Ecological Applications 8:559–568
11%
6%
5%
11%
49%
Schindler, David and Vallentyne, John R. (2004) Over fertilization of the World's Freshwaters and Estuaries,
University of Alberta Press, p. 1, ISBN 0888644841
40%
1%
14%
4%
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iron-rich stromatolites. Geomicrobiology Journal, 21, 331-340.
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