Although a lot of data was collected with each sampling point with the hopes of associating multiple factors with chloroflexus aurantiacus growth, the factor which I had a particular emphasis on was the water temperature as C. aurantiacus is a thermophilic bacteria. Thus, the first figure was created with the hopes of demonstrating this potential association.
Did you have any difficulties organizing, aggregating or summarizing your data?
Because the data comes from the percent cover of each quadrat, thresholding each image taken of the quadrats to obtain a percent cover value was time-consuming. Besides the data processing, organizing and generating figures has been relatively straightforward, although more work needs to be done to optimistically isolate any trends from the variables that may be occurring.
Was the outcome as you expected?
The outcome was not as expected. Because C. aurantiacus is a thermophilic bacterium, the expectation would be that as water temperature decreases, the bacteria coverage does so as well. My expectation was to see a decrease in bacterial cover and for the relationship to be either linear, exponential, or inverse (although other relationships are fully possible). However, in viewing the figure below, a somewhat bimodal distribution has formed with the percentage of C. aurantiacus coverage peaking at either end of the temperatures within the spectrum recorded. Each point is the average of triplicate measurements as well as reducing the chances of the data points being outliers. Additionally, the standard deviation was calculated for each of the triplicate groups and plotted on the lower graph to remove any notions of error being the cause for the lack of correlation.
Did your data reveal anything unexpected or give you any ideas for further exploration?
This data revealed that there is more at play in determining the amount of C. aurantiacus growth at a particular location. I have recorded many other variables with each sample and am excited to see if the data produces any discernible patterns. Additionally, there are variables that were not measured but absolutely play a role in C. aurantiacus growth such as the concentration of sulphur and other essential chemicals for growth in the water, the depth temperature of growth, and more. Because the depth of water was recorded with each sample, it may be interesting to correct the temperature values with the corresponding depth of each sample to see if this corrects the lack of pattern seen with the surface water temperature readings.
Figure 1. Average Percent Chloroflexus aurantiacus Coverage versus Average Surface Water Temperature. The percent bacterial cover in each quadrat was determined by photographing the quadrat and subjected to thresholding via ImageJ. The percent cover at each location was recorded in triplicate and averaged before being plotted. This data was plotted against the water temperature at each location. The water temperature was recorded in each quadrat and taken in triplicate. The triplicate measurements were averaged before being plotted against the percent bacterial coverage.