1. Coral Disease On Little Cayman Adam Catevenis Steven Savard

2. Coral Disease on Little Cayman Introduction Historical data suggests that White plague was most abundant between 1999 and 2004 on Little Cayman. Dark Spot was more prevalent between 2004 and 2006. It also suggests that the distribution of white plague affected colonies was found to be clumped [1]. Diseases are found to be more prevalent in degraded sites, and silt in run-off has been the leading cause of coral mortality worldwide [2] White Plague, Black Band, White Band, White pox, and Dark Spot Syndrome are the primary diseases on Little Cayman. Coral diseases may be found more prevalent in areas of high stress such as sites out of the marine park and where there is development. Increased areas of disease will also be related to increased areas of water flow, sedimentation, and high wave energy. A greater abundance of diseased coral is found in close proximity rather than random locations. Methods Surveyed 12 sites around the island. 5 transects were done for each site Transects were 30m long Along each transect, a record of each coral species and coral diseases was taken for coral colonies directly underneath the transect tape. Pictures were taken of each diseased colony encountered. A ruler was placed beside the affected area to more accurately calculate the percent cover of the disease for each coral. While one recorder is taking a picture, the other swam a circle with a 1-2 meter radius around the diseased coral and recorded the amount and type of diseases in the area. A record of water flow, sedimentation, and wave energy was decided for each site based on a 1-5 scale where 1 is the lowest and 5 is the highest Results References [1] Brandt M.E, Mabfrino C, McManus J.W, Coehlo V. The epizootiology of white plague in relationship to coral community change in a protected reef environment (Little Cayman, Cayman Islands, British West Indies). In review [2] Harvell C.D, et al. (1999) Emerging Marine DiseasesÑClimate Links and Anthropogenic Factors. Science vol. 285 p. 1505-1510 Coral disease affected a total of 9 species out of 16 identified. As seen in Figure 1, disease was found most prevalent in A. palmata (50% of population were diseased) and S. siderea. (22% of population were diseased). Figure 1, also shows the percent of the population affected by each disease. Dark spot was the most prevalent disease affecting mostly S. siderea and A. agaracities. The result of the t-test depicts how there is no significant difference in the percent of total coral diseased inside and out of the park, where there is development and lack of, and between the north and south side of the island. This can be seen by the overlapping error bars of the three graphs in Figure 3. When comparing sedimentation, water flow, and wave energy to the percent of diseased coral, it appears to be inversely related; as seen in Figure 2. However, comparison of the calculated R values indicate that there is no significant relationship between these factors and the percentage of disease. Discussion Our results are consistent with the previous data in that dark spot is the most prevalent disease affecting coral around Little Cayman. The most affected species were A. palmata and S. siderea. None of the factors studied were related to the percent of coral diseased. There was also no difference between location and the prevalence of disease. Further data should be collected to validate these observed results. Other unknown environmental factors may cause the spread of disease and should be studied.

3. Introduction Historical data suggests that White plague was most abundant between 1999 and 2004 on Little Cayman. Dark Spot was more prevalent between 2004 and 2006. It also suggests that the distribution of white plague affected colonies was found to be clumped [1]. Diseases are found to be more prevalent in degraded sites, and silt in run-off has been the leading cause of coral mortality worldwide [2] White Plague, Black Band, White Band, White pox, and Dark Spot Syndrome are the primary diseases on Little Cayman. Coral diseases may be found more prevalent in areas of high stress such as sites out of the marine park and where there is development. Increased areas of disease will also be related to increased areas of water flow, sedimentation, and high wave energy. A greater abundance of diseased coral is found in close proximity rather than random locations.

4. Methods Surveyed 12 sites around the island 5 transects were done for each site Transects were 30m long Along each transect, a record of each coral species and coral diseases was taken for coral colonies directly underneath the transect tape. Pictures were taken of each diseased colony encountered. A ruler was placed beside the affected area to more accurately calculate the percent cover of the disease for each coral. While one recorder is taking a picture, the other swam a circle with a 1-2 meter radius around the diseased coral and recorded the amount and type of diseases in the area. A record of water flow, sedimentation, and wave energy was decided for each site based on a 1-5 scale where 1 is the lowest and 5 is the highest

5. Results Coral disease affected a total of 9 species out of 16 identified. As seen in Figure 1, disease was found most prevalent in A. palmata (50% of population were diseased) and S. siderea. (22% of population were diseased). Figure 1, also shows the percent of the population affected by each disease. Dark spot was the most prevalent disease affecting mostly S. siderea and A. agaracities.

6. The result of the t-test depicts how there is no significant difference in the percent of total coral diseased inside and out of the park, where there is development and lack of, and between the north and south side of the island. This can be seen by the overlapping error bars of the three graphs in Figure 3.

7. When comparing sedimentation, water flow, and wave energy to the percent of diseased coral, it appears to be inversely related; as seen in Figure 2. However, comparison of the calculated R values indicate that there is no significant relationship between these factors and the percentage of disease.

8. Discussion Our results are consistent with the previous data in that dark spot is the most prevalent disease affecting coral around Little Cayman. The most affected species were A. palmata and S. siderea. None of the factors studied were related to the percent of coral diseased. There was also no difference between location and the prevalence of disease. Further data should be collected to validate these observed results. Other unknown environmental factors may cause the spread of disease and should be studied.

9. References [1] Brandt M.E, Mabfrino C, McManus J.W, Coehlo V. The epizootiology of white plague in relationship to coral community change in a protected reef environment (Little Cayman, Cayman Islands, British West Indies). In review [2] Harvell C.D, et al. (1999) Emerging Marine DiseasesÑClimate Links and Anthropogenic Factors. Science vol. 285 p. 1505-1510