Experimental Design

This section will be broken up in two sections. The first section will discuss the experimental methods used to answer the research question, ""Are chiton more likely to stay in tide pools with high algae diversity and are they more likely to not stay in an area of low algae diversity? "

The second section will discuss the methods to carry out the original hypothesis (to read about the intended hypothesis please click here). This section is included in the website because one can learn a lot from failure, possibly even more than from success.

Methods

After surveying several sites in Bermuda it was decided that the experiment would be conducted at Spittal pond. Spittal pond was chosen based on three factors; Spittal pond is a nature reserve (The research was done in the most authentic untouched habitat possible.); of all sites (Tobacco Bay, Whalebone Bay, South Shore Bay.) visited it contained the highest density of chiton per a m2; lastly there was a linear gradient of tide pools that had a high density of chiton per a tidepool. These factors presented a ideal environment for the experiment to be carried out. (please see video to your right to see the tide pools researched.)

The experiment was conducted at 13:30 each day during October 14, 15, 17, 2008. (Though intended to be four days long, a fourth day was not possible because the tide was so violent it was impossible to get to the research area without injury.)

Photography was used to document each tide pool. Each picture was designed to ensure that the entire chiton population within the tide pool was captured. (Since Chitons generally form clumps within pools this was a feasible method.) In addition extensive photos were taken of the tide pools in order to determine if each pool had high levels of algae substrate or low levels of algae substrate within them. The two algaes measured for were a fleshy rhodophyta and crustose coralline.

After each of the 4 tide pools was documented through photos. They were uploaded on a Mac book and a document was created through gimp,( a photo editor) that allowed for each days picture to form a line across the screen. Then using the paint tool, the chitons were numbered in the first days picture. Then each chiton in the first picture was looked over and attributes specific to each chiton were noted, such as the shape of unique colorings or markings on their dorsal plates, or unique growths of fleshy rhodophyta and crustose corallineon the dorsal plates.

After the attributes were marked the next step was to compare each chiton in the first picture of every tide pool to every chiton in the other pictures in every tide pool in order to see if the chiton left the tide pool or stayed in their tide pool. If a chiton was present in multiple pictures the same number was drawn over the respective chiton to identify that it had been matched.

After each tide pool picture had been interpreted the number of chiton that stayed within their respective tide pools was added up. The number of chiton to leave their respective tide pool was also added. Lastly the percent cover of algae substrate for each tide pool was estimated and was either deemed a high substrate tide pool or low. For this experiment there were two tide pools that were considered to have high growth and two that had low growth.

The numbers were than gathered into an excel spreadsheet and computed using a chi square formula.

The Hypothesis That Never Was

The original experiment was designed to tag the chitons with b-tags using superglue. After they were tagged a industrial grade spatula would be used to pry them from their substrate. After being removed the chiton would then be placed in tide pools according to the substrate growth on their dorsal plates. A chiton with heavy algae growth on their dorsal plate would have been placed in a low substrate tide pool while a chiton with no algae growth would be placed in a high substrate tide pool.

During the course of the next three days each chiton tagged would be searched for in order to see what location they choose to move. When the chiton was found, the substrate growth of the tide pool that the chiton was found in would be recorded. Since the hypothesis was that chitons with high substrate growth on their dorsal plates would move to tide pools with high algae growth and vice versus.

The first day on site, pictures were taken of each tide pools and a few videos were taken of the area. Afterwards I spent the rest of the afternoon trying to tag the chitons with the b-tags using superglue. Because most of the chitons were submerged in water it was a impossible task. The chitons not submerged in water were wet and were also unable to be tagged. So it was decided to try to remove the chiton and than tag them with b-tags.

Trying to remove the chiton from their substrate proved to be futile. Several different methods using the spatula were tried. Such as placing the spatula under a moving chiton with the hopes that they would crawl over the spatula, and than the simple lifting of the spatula would remove them. This proved to not work because the chitons foot would not be on the spatula only the mantle. The attempts at removing the chiton from their tide pool stopped once a chitons mantle was accidentally damaged. (Please see photo to your right.)

The next day I decided I would change my hypothesis a little and instead just tag the organisms within their pools without trying to move them to another pool. A professor suggested for me to try to tag the chiton in the pool using nail polish as it might work better. The Nail Polish did end up working better because I was able to paint a large area on the chiton and it did not wash off immedialely like the b-tag did. (Which I now regret tremendously as I read that they are extremely sensitive between their dorsal plates. I am afraid that I may have caused them pain or discomfort because of the fumes/chemicals.)

While the polish did stay on during my time at the pond, the next day it had washed off. It was at this point that I realized the only way I would be able to study the chiton would be through photographs (Thankfully I took many pictures of each pools the prior 2 days.) The third day I was unable to work however because it was far too dangerous. The 4th day I simply took more pictures of the tide pools and recorded other observations I saw.

In short my failure in my first hypothesis taught me that preparation is the most important aspect of any experiment. Though I was disappointed I could not pursue my original hypothesis I still benefited from my failure.