WISRD Research & Engineering Journal

4.1 Hand Measurements We tried a very simple method to take relative height measurements of the fragments from thirty images taken at our preferred time. Google Slides was chosen because photographs can be easily annotated with line segments and length of line segments determined as shown in Figure 34.

Figure 34 . Using Google Slides to calculate relative height of coral fragments. Google Slides provides measurement lengths from the top of the slide (the Y value), so it is not a direct size measurement. A total of 19 fragments were used over the 30-day testing period and a total of 20 measurements were taken from each image (two branches on the left side fragment were separately measured) as shown in Figure 35.

Figure 35 . Hand measuring 19 fragments. The hand method of measuring was not as difficult as initially expected because the growth in height (about 2 mm) was seen in only one fragment over 30 days. This should not be excluded as a way to quantify coral growth; however, the limitation of this method is that it does not capture lateral growth or emergence of branches. In addition, when some polyps are extended, they obscure the skeleton.

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