Megabenthos monitoring in Ternate, North Maluku

Abstract Several megabenthos groups have important economic and ecological values- also play an important role in the condition and stability of coral reef ecosystems. The important role of this megabenthos group makes it a potential object as an indicator to assess coral reef health. This study aimed to determine the condition of coral reefs by monitoring the megabenthos. The targeted megabenthos in this study consisted of eight groups (Holothuria sp., Diadema sp., Blue Starfish, Tridacna spp., Drupella, Trochus niloticus, Acanthaster planci, and Lobsters). Data collection was carried out in Ternate Waters at 14 stations using the Benthos Belt Transect method. The analysis was carried out by examining the presence and the number of species, distribution and density of each station, density of each type of megabenthos, and ecological indices (dominance index, diversity index, and evenness index). The results of the study found a total of 375 individuals. The group of megabenthos species that were always found at each station was coral polyp-eating snails (Drupella). On the other hand, Acanthaster planci and lobster were groups of megabenthos species found only at a few stations. Overall, Drupella was the most dominant type of megabenthos during observation, which may be related to overfishing at that location. Several groups of fish were natural predators of Drupella. Their numbers in the wild are decreasing due to overfishing. The dominance that occurred during observations was closely related to the health condition of coral reefs and the diversity of coral species as the habitat of megabenthos.