Morotai Island is well-known for its reef shark diving destination but we have yet to fully discern the density of the reef sharks and the correlation between the predator, carnivore and herbivore in Morotai’s South Waters. In a conservation management context, it is important to clarify the population of reef sharks and their relations with their lower trophic levels. Thus, we examined the existence of reef sharks with an abundance of herbivore and carnivore reef fishes in south waters of Morotai Island. We measured the existence of reef sharks with the Audible Stationary Count (ASC) methods and surveyed the abundance of herbivore and carnivore reef fishes using Underwater Visual Census (UVC) combined with Diver Operated Video (DOV) census. Pearson’s Product Moment Correlations was used to determine the degree of relationships between sharks and herbivore and carnivore reef fishes. The research from 8th April to 4th June 2015 showed the strong possitive correlations between existence of reef sharks with abundance of reef fishes. The correlation values between reef sharks with carnivore fishes, reef sharks versus herbivore fishes, and carnivore against herbivore fishes are 0.88, 0.77, and 0.72 respectively. This highlights the importance of reef fishes abundance management in south waters of Morotai Islands to enable the establishment of appropriate and effective reef sharks conservation.