Briefing

This activity is designed to be an extension of Investigation 4.2 in the curriculum.  We recommend that  you work through activity 4.2.3  before trying this investigation.  If you did not receive printed JASON IX curriculum you can access the curriculum files on your JASON@School CD-ROM.

Dr. Robbie Smith uses the tool of quadrat sampling on the reef to monitor the health of individual corals over time and to monitor algae growth on the reef.  To perform quadrat sampling, he puts a set of stakes into the bottom of the reef, then places a frame over the pegs and photographs the sample.  He photographs the exact same spot every few months, year after year, so that he can compare results to see if any change (growth or death of the corals) is taking place.  This is a long-term monitoring tool for measuring growth, mortality, and the frequency with which new corals become established on the reef.  

This  activity uses the authentic images Dr. Smith as taken .  You will use the tools here to count the corals and then compare the data for the two years. Dr. Robbie Smith suggests that students collect the data in image pairs, one from 1993 and one from 1997. We have arranged the images in two sets—1993 and 1997—for the same quadrats. In this way, students can compare as few as one set of images, or combine data with other team members from the rest of the class. If several teams work on different images, they should be able to collect data for about thirty images.

Dr. Smith recommends that students collect data from as many images as possible so they can draw valid conclusions from the sample. Students can tally their counts on paper, then enter the totals into the Data Sheet. Once the data is entered, they can press the "Graph It!" button to generate a graph based on their data. They can then discuss the questions on the Analysis page, and explore other Web links about coral reefs. Students can also explore the reef by viewing a  QuickTime Virtual Reality panorama of Bermuda's coral reefs.

We recommend that you work through the tutorial before you begin to actually collect your data.