the effects of calcium magnesium acetate on lumbriculus
TRANSCRIPT
Experiment and Findings by Jordan Turner, Kayce Cook, and Lauren
LaganaHCOP PE 2008
The Effects of Rock Salt(Calcium Magnesium Acetate) on
Lumbriculus variegatus
Background of Chosen Solutions…
CMA, or Calcium magnesium acetate, is a form of rock salt used for deicing roads and highways. It affects the melting point of the ice, lowering it enough to melt in below-freezing weather.
The solution is extremely hypertonic, drawing water from animal cells to reach equilibrium.
Our chosen solutions for the pulsation test: Control (Spring Water), Group I (1% CMA and Spring Water solution), Group II ( 5% CMA and Spring Water solution).
HypothesesWe hypothesize that the CMA solution will
affect the L. variegatus ‘s pulsation rates by speeding them up because the solution is hypertonic, pulling water from the worms’ bodies and increasing their pulsation rate.
We hypothesize for the locomotion test that the CMA solution will decrease locomotion rate compared to the control group in spring water by drawing water from the worms into the hypertonic solution.
We hypothesize for the chemotatic test that L. variegatus will react to the CMA solution as a repellant, and will move away from it.
Pulsation Experimental Design
Control Group 1%
CMA
5% CMA
30 Worm
s
10 Worm
s10
Worms
10 Worm
s
Materials and Methods for Pulsation Test
• Control Group: 10 worms• 1% CMA Test Group: 10 worms• 5% CMA Test Group: 10 worms• Placed each test group in assigned solutions, allowing
the worms to be exposed for 10-15 minutes. Extracted the worms after allotted time period and measured their pulsation rates within 10 seconds, and multiplied by 6 to get pulsations per minute.
• Statistical analysis was performed using ANOVA (JMP v. 7 SAS). Model effect tested was treatment. Mean comparisons were determined using Student’s t-Test. Data are reported as means ± standard deviations.
• Calculated mean and standard deviation.
Locomotion Experimental Design
30 Worms
Control Group
0.5% CM A
1% CMA
10 Worms
10
Worms
10 Worm
s
Materials and Methods for Locomotion Test
Control Group: 10 worms0.5% CMA Test Group: 10 worms 1% CMA Test Group: 10 wormsPlace each group of worms into assigned
solutions, exposing them for 10-15 minutes.Build the track to measure the distance traveled
by each worm, marking in centimeters. Extracting the worms, place one by one into the track, measuring the distance for 30 seconds. Multiply by 2 to get distance traveled per minute.
We calculated the mean, standard deviation.
Chemotatic Experimental Design
30 Worms
Control Group
0.5% CM A
1% CMA
10 Worms
10 Worm
s
10 Worm
s
Materials and Methods for Chemotatic Test
Control Group: 10 worms0.5% CMA Test Group: 10 worms1% CMA Test Group: 10 wormsSeparating the test worms, place each
worm into a petri dish and apply one drop of the assigned solution to its tail, monitoring behavior for 30 seconds. Results depend on a positive response (moving back towards its tail) or a negative response (moving away from its tail) to the differing solutions.
Response to CMA solutions
02468
1012
Control 0.5%CMA
1% CMA
treatment groups
Num
ber o
f wor
ms
Positive
Negative
Chemotatic Test Chart
Summary of Results and Conclusions
Pulsation rates increased with the addition of 1% CMA solution. This supported our hypothesis. However, we also discovered that 5% CMA solution was too concentrated for our worms, resulting in death. We decided to create a weaker solution of 3% CMA.
There was a significant difference in the mean distances traveled by our two test groups. The group with 1% CMA solution traveled less distance, supporting our hypothesis. However, 3%CMA solution also caused death. We created a final solution of 0.5% CMA.
We hypothesized that the worms would be repelled by the CMA solution. For both CMA concentrations (0.5% and 1%), 70% of the worms reacted positively by moving toward the solution.
DiscussionAlthough we routinely use rock salt as a de-
icing agent on roadways and highways for safer travel, it was found to be lethal to California black worms at high concentrations. Harm to invertebrates could become evident on roadways near streams and rivers. In the laboratory, CMA was found to alter their physiology. By adding CMA to roadways, we are adding additional salt to the environment which could pose a risk to freshwater organisms.
Sources and CitationsSardo, Soares, Gerhardt. “Behavior, Growth, and
Reproduction of Lumbriculus Variegatus (Oligochaetae) in Different Sediment Types”. Human and Ecological Rich Assessment, 13:519-526, 2007.
http://www.informaworld.com/smpp/content~content=a778588780~db=all~order=page
Cushman, J.R.; Duff, V.A.; Butfau, G.H.;Aust, L.B.; Caldwell, N.; Lazer, W.. “Evaluation of CMA and Road Salt for Contact Hypersensitivity Potential and Dermal Irritancy in Humans”. Contact Dermatitis (01051873) Apr91, Vol. 24, Issue 4, p.289-292
http://www.ncbi.nlm.nih.gov/pubmed/1831107
Sources and Citations Continued
McFarland, B.L.; O’Reilly, K.T.. “Environmental Impact and Toxicological Characteristics of Calcium Magnesium Acetate”. Chemical Deicers and the Environment. Lewis Publishers, Boca Raton, Florida.1992. p 192-227. 9 fig, 6 tab, 50 ref.
http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=9306831