Chloride Salt Effects on Algal
Populations
And the Dangers that they Present
By:Brandon Perrotte
Central Catholic
2008
Introduction
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Chloride salts have potentially harmful effects on
algae.
These salts enter the ecosystem due to runoff. They
prove to be corrosive and harmful to the
environment.
The chloride salts, when used cause the decrease
in population of thousands of organisms, especially
algae.
This would therefore affect the organisms that feed
off of the algae and would then disrupt the
environment.
Background Information:
Chloride Salts
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Chloride Salts are binary compounds of
chlorine. They can be corrosive and are
soluble in water.
The salts used in the experiment were
sodium, magnesium and calcium chloride.
Some solid chlorides can be decomposed
through the process of hydrolysis.
Environmental Effects and
Inhibitions of Chloride Salts
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We use sodium chloride, or common road salt, to
clear the ice from our streets as to prevent
accidents and injury.
This act is also inducing runoff into small marine
and wildlife ecosystems as the wheels of cars push
them into the soil and into streams and rivers. The
runoff contains harmful chemicals.
This is harmful to thousands of small organisms
and their habitat. It also in low proportion gives a
low toxicity level to the water that we drink and use
for common practices such as brushing our teeth
and showering daily.
Chloride Levels in Streams
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Minnesota passed laws restricting salt
use for its disruptive corrosion and for
the reduction of water pollution
Discriminative Algal Traits
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Euglena
It is a common protist and
functions in sunlight.
It is commonly cylindrical in
shape.
The chloroplasts in
euglena are clear.
The paraflagellar that
controls light absorption
monitors light shields the
photoreceptor.
The algae can function
without sunlight by taking
nutrients from decomposed
organisms.
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Chlamydomonas
Chlamydomonas are
unicellular flagellates.
They operate on
sunlight as a
photosynthetic plant.
The ion channels such
as channelrhodopsin
are activated by light.
Purpose
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The Purpose of this experiment is to
identify the potentially harmful effects
of chloride salt concentrations on two
different algal populations.
Hypothesis
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The null hypothesis in this experiment
states that the chloride salts will not
increase the population of algae and
possibly present dangerous
circumstances for the remaining
population.
Materials and Methods
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Materials
Borosilicate test tubes(72)
Spectrophotometer(1)
Fluorescent lamp(1)
A large container of spring water
2(?)mL containers of both euglena
and chlamydomonas.
5ml pipette
200 microliter pipette
Three containers of sodium chloride,
magnesium chloride, and calcium
chloride.
Test Tube Racks(2)
One Sharpie marker
Micropipette and pipette tips
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General Experimentation
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Six sets of test tubes were
filled with different
concentrations of water, algae,
and a variable. They were
placed in a test tube rack and
were given light by an
overhanging fluorescent lamp.
A spectrophotometer was
used and set at a blue-green
wavelength(503nm).
The tubes were then placed
into the spectrophotometer
and tested every three days
five times.
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Procedure
1.
2.
3.
4.
5.
36 borosilicate test tubes were placed in both test tube racks.
12 tubes were placed into each row.
The top of each test tube was marked with a Sharpie marker
to indicate the placement of the tube in the
spectrophotometer.
The tubes were then filled with different concentrations of
algae, spring water, and one of three chloride salts. Pipettes
with assigned tips. 2ml of algae was the constant amount.
The pipettes must never cross-contaminate between chloride
salts and algal species.
Concentrations of the stock solution were divided as 0%,
10%, and 40%. Four tubes in each row were designated to
contain one of the three concentrations.
Procedure (Continued….)
6. The control group in the experiment was a group of six tubes that contained 3ml
of algae(60%) and 2ml of algae(40%) without adding any of the variable.
7. In the first set of 36 test tubes euglena was mixed in concentration with sodium
chloride, magnesium chloride, and calcium chloride. They were divided into
sets of twelve tubes assigned to each variable.
8. The same procedure was done as in step 7 only replacing euglena with
chlamydomonas as the algal population being affected by the chloride salts.
9. Once all solution has been inserted into the test tubes, the tubes are then taken
out of the test tube rack and placed into the spectrophotometer at the mark
made earlier in the experiment by the Sharpie marker. Absorption readings
are then taken. These are taken to indicate the effect of the different
concentrations of chloride salts on algal populations.
10. Step 9 was repeated every three days for fifteen days while the light of the
fluorescent lamp remained constantly over the tubes. Readings were then
recorded and analyzed in an ANOVA statistical analysis.
ANOVA
From the results of the
ANOVA’S conducted a p-value
graph was created and it is
shown below.
The increments
0.6
in the legend
0.5
compare both
concentrations
0.4
of the chloride
0.3
salts used.
Amount of p-value
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Euglena p-values
Sodium Chloride A-0%-A-10%
Sodium Chloride A-10%-A40%
Sodium Chloride A-0%-A-40%
Magnesium Chloride B-0%B10%
Magnesium Chloride B-10%-B40%
Magnesium Chloride B-0%-B40%
Calcium Chloride C-0%-C-10%
Calcium Chloride C-10%-C40%
Calcium Chloride C-0%-C-40%
0.2
0.1
0
Concentration values
Sodium Chloride A-0%-A-10%A-40%
Magnesium Chloride B-0%-B10%-B-40%
Calcium Chloride C-0%-C10%-C-40%
Resulting Graphs and
Information
The charts below rely on the average absorbency of light by the
algal populations of chlamydomonas and euglena.
Chloride Salt Effects on Chlamydomona Poulations
80
20
60
10
40
20
Sodium Chloride
0
-20
0%
10%
40%
Magnesium Cl
Calcium Chloride
-40
-60
-80
-100
Absorbancy at wavelength 430nm
Absorbancy at wavelength 430nm
Chloride Salt Effects on Euglena Populations
0
0%
10%
Sodium Chloride
-20
Magnesium Cl
Calcium Chloride
-30
-40
-50
-60
Concentration of selected variables
40%
-10
Concentration of selected variables
Conclusive Effects of the
Chloride Salts on algae
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The chloride salts had a negative long term effect
on the algal populations of both euglena and
chlamydomonas.
This may have been due to the corrosive properties
of the salts or it may have been just the
concentration of the salt that it that made up its
habitable environment or in this case inhabitable
environment.
Referring to the graphs of average absorbency on
the previous page the algae thrived when there was
not a very high concentration of salts.
Potential Harm To
Environmental Algae
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These results show that algal populations in
the environment are at a great risk of
decreasing in size because of the potential
abuse and misuse of chloride salts.
The communities at the greatest risks are
the ones near roadsides where road salts
are being used to clear ice for safety.
This effects many environmental organisms
and ultimately the ecosystem that the algae
made up.
Conclusion
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It is concluded in this experiment that the
decrease in the algal populations was due
to the chloride salts inhibition of growth.
The chloride salts at a higher concentration
killed masses of algae and caused them not
to grow back.
This shows potential for the same
happenings in the surrounding environment.
Extensions
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Some extensions that could have improved
the quality and obvious depth and
extensiveness of this experiment is the use
of more tubes in the experiment and the use
of different concentrations.
Some mistakes made in this experiment
was the misplacement of the test tubes in
the spectrophotometer instead of being
placed in the same position of every time.
The same results were found twice in two
testing trials as well.
Works Cited