Corallivore became one of the biotic components that relate with coral coverage. The objective of this study was to determine the trophic structure of reef fishes, as well as the relationship between corallivores and hard corals in the northern part of Kepulauan Seribu. Reef fish species and benthic coverage were assessed using underwater visual census (UVCs) and Line Intercept Transect (LIT). The results showed that there were 120 reef fish species belonging to 7 trophic groups and 19 families. Pomacentridae and Labridae are the most abundant fish families. Based on reef fish components, Sepa Besar reef fish characteristics were dissimilar than the other sites. The highest coral cover was found in Pelangi Island, which related with the high abundance of corallivores. An abundance of corallivore groups showed a positive correlation (R2 = 0.7786) with hard coral cover. The abundance and diversity of reef fish were affected by the availability and variety of food. Our study shows that coral covers affect the abundance of corallivore fishes. Variability and existence of food for reef fishes are really important for resort priprietors to be aware of especially for those who manage diving and snorkeling activities.

To select a rehabilitation area of coral reefs in Pahat Island within Anambas Islands, this study was conducted to asses coral reefs condition using diver-towed or manta tow surveys and underwater photo transects (UPT). The results of the manta tow surveys showed coral cover dominated by hard corals percentage ranged between 11% and 50% (categories 2 and 3) in the western, northern and southern parts of Pahat Island. Distribution of hard coral percentage with more than 50% (Category 4: 51% - 75% and 5: 76% -100%) was observed in the eastern part of Pahat Island. While results from UPT showed the hard coral percentage of 62.5%, 33.67% and 17% in the eastern, western and northern of Pahat Island, respectively. There are similarities in the results of coral reef cover Obtained by the manta tow and UPT methods. Conclusions, this study recommends western Pahat Island as a good alternative for a rehabilitation site as the coral coverage was in poor condition.

Sangiang Island had been established as a Nature Recreation Park (TWA) in Indonesia, that requires comprehensive data support for good management. The rise of marine tourism that increased in TWA Sangiang Island behoove to be a concern, especially in coral reef ecosystem. The study aimed to determined the condition of the coral cover and the biomass composition of coral reef fishes, then to identify parameters that affect coral health and the coral reefs health index in TWA Sangiang Island. The observation was carried out in area near to the estuary (Legon Waru), entry point for shipping (Tembuyung), and diving tourism (Legon Bajo). The highest of biomass of target fish was Legon Bajo (0.013 kg / ha) and the lowest was Tembuyung (0.002 kg / ha). Coral reefs health index values in each station varied from 1 (low) to 4 (high). Coral reefs health index in Legon Waru was strongly influenced by live coral cover, and also in Legon Bajo was influenced by live coral cover, rubble and biomass of target fishes, while in Tembuyung was much influenced by fleshy seaweed cover. The results indicated that the coral reef ecosystem on Sangiang Island wasn’t in good condition as a whole.

Patterns of community structure within coral reefs ecosystems are strongly influenced by a catastrophe such as a tsunami. Sumur is one of the coastal regions affected the most by the Banten Tsunami in December 2018. This research aims to predict coral reef ecosystem conditions after a tsunami based on the reef fish community structure and benthic coverage in the previous month. The research was conducted on every island around Sumur coastal region. Reef fish specimens were sampled using underwater visual census, and benthic coverage was taken with quadrats for Coral Point Count Estimation (CPCe). Overall coral condition assessed by conservation value determined through coral morphology. The highest coral coverage was found in Sumur, Southwest Oar, and North Badul. Nearly all sites have a high diversity reef fish community, with the highest abundance and species richness found in West Umang and North Badul. Badul island, Mangir island, and Cigorondong were categorized as the locations with coral reef ecosystems with the highest stress-tolerators. Most areas with this high stress-tolerator are predominated by coral massive and sub-massive and have higher endurance than other sites. Post-catastrophe, reef fishes will shift to the sites where most coral reef-building has survived, especially reef fishes with territorial behaviour.

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