Coral Disease Prevalence on Scleractinian Corals at Prigi Bay, Trenggalek, East Java

Abstract

Coral disease prevalence is defined as the ratio of diseased coral colonies to total colonies in a certain place. Coral community health is determined by measuring coral colony health using an index based on the percentage of diseased coral colonies within a quadrat transect. Disease in coral can be triggered by environment factors. Declining seawater quality leads to stress of the coral host and faster growth of pathogens both in the water and the body of the corals, caused coral disease. Prigi Bay is a heavily used area that has valuable ecosystems including coral reefs; however, nowadays the high level of anthropogenic activities in this bay is becoming a threat to coral health. The aim of this research was to examine the coral disease prevalence in Prigi Bay. Three stations were selected as coral disease monitoring stations: Patuk Sewu, Watu Lunyu, and Damas. In total, we surveyed 5,057 coral colonies. The highest coral disease prevalence was found at the Patuk Sewu station (17.23%), while at the Watu Lunyu and Damas stations prevalence was 3.31% and 3.15%, respectively. High coral disease prevalence in Patuk Sewu may cause by the abundance of explained growth anomalies (EGA). EGA is strongly correlated with water quality, which has been associated with the kinds of disease observed. Since Prigi Bay is in the utilization zone, with a busy fishing port and fish processing industries that are likely sources of pollution which could influence water quality and the health of the environment. Coral disease prevalence in Prigi Bay can be considered as high, and future research should focus on other aspects of coral condition and the stressors affecting corals.