Patrick Leech
Pittsburgh Central Catholic
PJAS 2009
Runoff
 Surface runoff
 Materials that are commonly transported by surface
runoff are fertilizers, petroleum, pesticides,
herbicides, and SALT
Runoff continued
 Not only harms aquatic plants but also affects drinking
water



Ontario research team discovered that only about 45%
of salt stays on the surface of the water
Rest absorbed in shallow aquifers
Exceeds recommended safe amount of salt for
drinking water
Former Experiments
 Effects of road salt on the environment were first
noticed in the 1950s
 Along the Minnesota highway, trees within a 3.4 mile
radius of the road were showing indications of salt
related death.
 During the same time period the New Hampshire
Government reported the death and removal of about
14,000 trees due to salt related problems.
Algae
 Most algal deaths result from salt intrusion
 During winter, road salt runoff increases algal death
 Many attempts have been made to create a safe ice
melt salt
Algal Importance
 Base of aquatic food chain
 Used as a bio-indicator for
aquatic environments
Calcium Chloride(CaCl2)
 The most universal road salt
 Exothermic reaction with water heats up ice or snow
 Lowers the freezing point of snow (colligative
property)
Dehydration
 Directly alters tonicity of organisms
 Cells lose water through hypertonicity when exposed
to salt
 Some salts can be toxic at high concentrations or
interfere with biological processes
Safe Salt
 Ex. “Safe Paw”
 Has a dual effect in which a liquid is released instantly
melting snow distant from the pellet
 Core immediately heats up melting snow directly
around it
 Exothermic heat process
 Claims- environmentally safe and
lessens irritation to
animals (dogs paws)
Euglena
 Common algal like protist
 Extremely tolerant of many habitats
 Capable of survival in both salt and water
environments
 A partial heterotroph can attain food through
endocytosis and photosynthesis
Chlamydomonas
 Common unicellular algae
 Valuable experimental model for biochemistry,
genetics, etc.
 Exclusive to this organism are ion channels that are
directly stimulated by light
Purpose
 To determine if a “safe salt” has any effect on algal
growth/survival
Hypothesis
 Null: The presence of “Safe Paw” will NOT have a
significant effect on either Euglena or
Chlamydomona’s growth/survival
 Alternative: The presence of “Safe Paw” WILL have a
significant effect on both Euglena and
Chlamydomona’s growth/survival
Materials
 20% Safe Paw solution (20 grams Safe Paw per 100mL
Spring water)
 Euglena gracilis
 Chlamydomonas rheinhartii
 Soil water (sterile)
 Spring water
 30 test tubes (13 x 100 mm borosilicate culture tubes)
 Pipettes (macro + micro)
 Pipette tips
 Science Kit Educator spectrophotometer
 Test tube rack
Procedure
1.
The following ingredients were pipetted into 13 x 100mm borosilicate
culture tubes:
0% salinity
.1% salinity
1% salinity
Euglena
3mL
Chlamydomonas
3mL
3mL
Spring water
1mL
1mL
1mL
Chemical (Safe
Salt)
0mL
.05mL
.5mL
Soil Water
1mL
.95mL
.5mL
Total mL in test
tube
5mL
5mL
5mL
Procedure continued
2. Placed tubes on window that received an equal
amount of light
3. Algal growth was monitored every day for one week
using a spectrophotometer set at 430 nm
Euglena Growth Curve
0.35
Absorbance at 430 NM
0.3
0.25
0.2
0% chemical
chemical
0mL
.1% chemical
.05mL
chemical
0.15
.5mL
chemical
1% chemical
0.1
0.05
P-value= .0666
P-value= .0677
0
Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7
Time Elapsed (Days)
Chlamydomonas Growth Curve
Absorbance at 430 NM
0.25
0% Chemical (control)
.1% chemical
1% chemical
0.2
0.15
0.1
0.05
P-value= .057
P-value= .062
0
Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7
Time Elapsed (Days)
Results and Conclusions
 The null hypothesis, that the presence of “Safe Paw"
will NOT have a significant effect on both algae’s
growth/survival, is ACCEPTED (p-value > .05)
 The alternative hypothesis, that the presence of “Safe
Paw” WILL have a significant effect on both algae‘s
growth/and survival, is REJECTED
Limitations and Extensions
 Limitations
 Algae was not kept at the same temperature each day
 Weather variations could have small effects of data
 Only tested two concentrations
 Did not utilize a negative control (Calcium Chloride)
 Algal cultures might not have been in optimal health
 Extensions
 Greater sample sizes.
 Algal health- the study will be repeated using a fresh
culture and a longer period of observation
Sources
 "Evaluating Support for the Current Classification of Eukaryotic Diversity".
PLoS Genet. 2 (12): e220. doi:10.1371/journal.pgen.0020220. PMID 17194223.
p://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1713
255.
 alga, algae". Webster's Third New International Dictionary of the English
Language Unabridged with Seven Language Dictionary. 1. Encyclopedia
Britannica
 "De-icer damaging thousands of trees on mountain passes". The Seattle Times
(19 March 2008). Retrieved on 18 March, 2008.
 Aliphatic Chains of Esterified Lipids in Isolated eyesptos of Euglena gracilis var.
bacillaris1
 www.oercommons.org/courses/algae-experiments
 en.wikipedia.org/wiki/Spectrophotometer
Sources continued
 Chapman, V.J. (1950). Seaweeds and their Uses. London: Methuen & Co.
Ltd
 Round, F E (1981). The Ecology of Algae. London: Cambridge University
Press.
 hamptonroads.com/2008/01/odu-experiment-turning-sewage-
algaebased-biodiesel-flourishing
 www.dow.com/productsafety/finder/cacl