It's been an eventful few weeks, and it was great to see that our hard work payed off last Saturday. With time to review and analyze the collected data, we have come to several conclusions. However, before I announce our conclusions, I think it's important that we highlight the variables within the experiment:
Independent Variable(s):
- N/A
Dependent Variable(s):
- Voltage read by Light Meter*
Control(s):
- Equipment (e.g. Light Meter, beakers, distilled water samples)
- Temperature of water samples - Room temperature
- Location of sample collections - Sites 1-6
- Volume of water samples
*Light Meter: A device created by our very own Mark Wheen. The "Light Meter" measures the amount of voltage that is recorded through the transmittance of the water. By rule of thumb, the measurements are inversely proportional; an increased amount of recorded voltage means that there is a decreased amount of light that is transmitted through the water samples (i.e. the water is less transparent), and vise versa.
If you refer back to the results previously posted, you can see that during the first and second tests, the water from sites 4 and 5 had the lowest voltage reading, and thus, we most transparent. You can follow this pattern to analyze the remaining data.
Conclusion:
In our original hypothesis, we concluded that the water closer to the Pedder Bay Marina would be less transparent due to the lack of constant water flow, and because it's assumable that the shallower water could be contaminated with the sediments below. However, referring to the data collected from our first test through the light meter, our hypothesis was disproved. The water near the Green Buoy was less transparent. Nevertheless, our the results from our second test matched up with our hypothesis. On the other hand, there are several factors which could have affected, limited, and hindered our results.
Throughout the experiment, we neglected to take into consideration the affects of the water temperature, salt concentration within the water, external light (in relation to the measurements made with the Secchi Disk), tides, currents, amount of rain water from the previous night, e.t.c. Furthermore, the samples of water we collected for testing with the Light Meter were from the surface of the water, whereas the visibility of the Secchi Disk was measured several 10's of centimeters underwater. Although the distance in between the two mediums were only a few meters apart, the temperature as well the concentration of the sediments could have varied exponentially and hindered the visibility of the water.
Upon completing our tests with the Light Meter, we conclude that the results from the second test (i.e. water from the Marina is less transparent) were more "accurate," because they complied with our hypothesis. However, the water samples had been sitting in room temperature for over 1/2 hour by then. What we might have perceived as a flaw within our experiment might actually be hinting to areas we should concentrate on for further study within our experiment. Perhaps the lower transparency of the water near the Green buoy, as presented in Test #1, was not so much as inaccurate, but had the affects of temperature influencing our the results. With more time and possible resources, e.g. thermometer, we would have been able to measure the water temperature of the samples upon collection, and furthermore, find if there is a correlation between the temperature and amount of visibility within the water.
Needless to say, with the time and resources we were granted, I believe the group did a great job and I would like to thank all of those who made this experience possible. Congratulations everyone! Job well done!
"The most beautiful experience we can have is the mysterious - the fundamental emotion which stands at the cradle of true art and true science"
-Albert Einstein, 1931
nice ;)
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