Coral Bleaching Experiment Systems

Abstract

The declining of coral reef ecosystem has been observed over the last 30 years and projected to continue declining in the future because corals are sensitive animals towards any changes in their surrounding; temperature, nutrient and water clarity. Coral bleaching is one of disaster affected by natural or human impact towards coral reefs. Mass coral bleaching events has been going on since 1998 and getting worse in 2010 and 2016 throughout the whole world, including in Malaysia. Increase of slightly higher temperature can interrupt the coral-zooxanthellae relationship, and leading to coral whitening, aka coral bleaching. Coral bleaching experiments has been done through the years from various countries to aid in coral conservation and restoration to identify the degree of bleaching towards stressors. In this study, coral triangle in South-east Asia region is the focused area because of the high diversity of coral species growth. The main species in Pulau Bidong, Terengganu, Malaysia, Acropora digitifera was chosen for this study, studied its bleaching criteria by examined the coral polyps and colour changes after synergistic effect of temperature and nitrates, the stressors. The coral nubbins were experimented in three sets of optimum, high and higher of temperature and nitrate levels in laboratory for 3 days. Its physiological changes were recorded every 12 hours. Differentiate this study with other coral bleaching experiment systems; their highest temperature been applied to the corals, the duration of the elevated temperature that corals can withstand, and the species that have been used in the coral bleaching experiment. Thus, this study can contribute knowledge to identifying A. digitifera as super coral for its resilience and resistance in husbandry. However, more studies need to be done on identify the genes that make them more tolerant and can be used in enhanced coral breeding.