Method for Calculating the Coral Health Index (Case Study: Mapur Island, Bintan, Indonesia)

¹ Marine Science Department, Faculty of Marine Science and Fisheries, Raja Ali Haji Maritime University, Politeknik Senggarang Street, UMRAH Campus, Senggarang, Tanjungpinang, Indonesia.
² Faculty of Engineering and Maritime Technology, Universitas Maritim Raja Ali Haji, Politeknik Senggarang Street, UMRAH Campus, Senggarang, Tanjungpinang, Indonesia.
³ Marine Animal Ecology, Wageningen University and Research, The Netherlands

^* Corresponding author: risandi@umrah.ac.id

Abstract

This study evaluates the health and condition of coral reefs in the Mapur Island - Bintan Conservation Area, located in the Riau Islands Province, Indonesia. The research was conducted at 5 site locations using the Underwater Photo Transect (UPT) method, with a focus on hard coral cover and the Coral Health Index (CHI). Coral lifeform data were analyzed using Coral Point Count with Excel extensions (CPCe) software. The results revealed significant variability in coral cover, ranging from 14.47% to 59.27%, with an average of 39.36%, placing the coral reefs in the “Moderate” category. However, despite high hard coral cover at some sites, coral health varied, with certain locations exhibiting significant disease prevalence. Among the 5 sites surveyed for CHI, four were classified as “healthy,” while one were categorized “diseased.” Statistical analyses, including Welch’s t-test and Bayesian inference, indicated no significant difference between the CHI and hard coral cover, suggesting that high coral cover does not necessarily imply a healthier reef. Diseases such as Pink- Blotch Syndrome, Black Band Disease, and White Syndrome were prevalent across several sites, highlighting the influence of environmental stressors on coral health. The study underscores the importance of regular coral health monitoring and the need for conservation efforts to mitigate the impact of coral diseases and climate change. These findings provide crucial insights into the status of coral reefs in the Mapur Island - Bintan Conservation Area and contribute to broader efforts to preserve marine biodiversity.