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Mass bleaching occurred in 2010 in Southeast Asia waters such as Thailand, Malaysia, and Indonesia. One of the Indonesian waters that experienced bleaching was Weh Island area, which then underwent bleaching again in 2016 and had impacts on the coral ecosystem. Substrate changes and coral cover conditions are noteworthy to determine the potential for coral recovery after bleaching. Therefore, the study aims to measure the condition of coral cover and the potential for coral resilience after bleaching in 2016. Benthic data collection used the Point Intercept Transect method while measuring coral resilience potential used the resilience index through coral cover indicators, fleshy seaweed, and rubble. The observation showed that the coral cover in the waters of Ujong Seuke was 34%, fleshy seaweed by 2.83%, and rubble by 21.17%. This research concludes that the condition of coral reef ecosystems after the bleaching phenomenon in 2016 was in moderate condition, and it has a high potential for resilience. [ABSTRACT FROM AUTHOR]

Mass coral bleaching events may have disproportionate effects on branching corals, leading to coral community restructuring, reduced biodiversity, and decreased structural complexity. This affects overall reef health and resilience. Functionally important, fast-growing branching Acropora corals were a historically dominant and vital component of Indonesian reefs throughout the twentieth century, yet the genus is also one of the most vulnerable to external stressors. This study used long-term annual reef monitoring data from Indonesia's Wakatobi Marine National Park (WMNP) to investigate the effects of a mass bleaching event in 2010 on Acropora and other branching corals, evaluate their post-disturbance recovery trajectories, and analyse shifts in coral community composition. Post-bleaching scleractinian coral cover decreased across study sites, with losses in branching corals especially evident. Long-term branching Acropora cover decreased significantly and failed to demonstrate the significant post-disturbance recovery of other branching corals (especially Porites). In areas characterised by relatively high branching Acropora cover (> 15% mean cover) prior to bleaching, long-term coral community composition changes have trended predominately towards branching and massive Porites and branching Montipora. The novelty and key contribution of this study is that results suggest suppressed recovery of Acropora in the WMNP. Contributing factors may include the Allee effect (inhibition of reproduction at low population densities), other forms of inhibited larval recruitment, direct and indirect spatial competition, and changes in the physical reef habitat. These findings have critical implications for this functionally important taxon, future reef conservation efforts, and overall reef health and resilience in the park. [ABSTRACT FROM AUTHOR]

Arenga pinnata "ijuk" fiber is one of the lignocellulosic sources that is abundant in Indonesia. At present, this fiber is only for brush, shiever, mat, and rope. Delignified "ijuk" fiber is a potential source of cheap crystalline cellulose, a material that can be used for composite. This paper presents chemical treatment of A. pinnata "ijuk" fiber to get cellulose with high crystallinity. The fiber is treated by alkalization with 2% sodium hydroxide (NaOH) for 1 h, 0.01 n KMnO4 as NaClO activator for 10 min and bleaching with 5% NaClO at varying time of treatment 3, 5, 7 h, respectively. For comparison, the fiber is treated with 2% sodium hydroxide (NaOH) for 1 h and then with 5% NaClO without KMnO4 for 3 h (N3). Addition of KMnO4 as NaClO activator will control ClO gas released and then the bleaching process becomes more effective because the ClO gas will bleach the fiber, not releasing fast to the air. Furthermore, NaClO leads an oxidative fragmentation from the remaining lignin and then the lignin dissolves out from the fiber. The result shows that the highest crystallinity of the cellulose is the fiber which is treated by alkalization with 2% sodium hydroxide (NaOH) for 1 h, 0.01 n KMnO4 for 10 min, and oxidation with 5% NaClO for 5 h (KN5). Fourier transform infrared confirms the removal of some lignocellulosic components such as lignin, wax, and hemicelluloses; X‐ray diffraction reveals an increase of crystalline parts in the fiber via cellulose through crystallinity index value. Field emission scanning electron microscopy displays dimension and surface morphology of fiber. So the treatment can remove some amorphous part of the lignocellulose namely, lignin and hemicellulose to obtain cellulose with high crystallinity. [ABSTRACT FROM AUTHOR]

Coral reefs face an uncertain future under global climate change, with thermal-induced bleaching increasing in frequency such that corals will soon experience annual severe bleaching (ASB). Marine Protected Areas (MPAs) are therefore becoming increasingly important as a conservation tool. Here we evaluate (i) Indonesia's coral reefs' spatial variation in ASB, (ii) whether reefs projected to have a later onset of ASB (i.e. possible climate refugia) are protected within MPAs, and (iii) the ASB risk profiles for reefs related to MPAs receiving priority investments. Our results highlight considerable variability across Indonesia's reefs being at risk of ASB. The ASB risk before 2028 is greater for coral reefs protected by MPAs versus those outside MPA boundaries. The ASB risk before 2025 is greater for coral reefs protected by priority MPAs versus those protected by non-priority MPAs. Overall, our results show that only ∼45% of the coral reef areas that are currently located within MPAs will likely act as thermal refugia (ASB > 2044). This is unsurprising given that the MPA network in Indonesia has been established over many decades, with most MPAs designated before suitable bleaching risk projections were available to inform MPA placement. Our results highlight the scope to further incorporate potential climate refugia for reefs into new MPA designations. This study also provides strategic information, which can support the development of Indonesia's long-term MPA and coral reef conservation strategy to effectively manage, mitigate, and adapt to the impacts of climate change on coral reefs. [ABSTRACT FROM AUTHOR]

Anthropogenic stress has been shown to reduce coral coverage in ecosystems all over the world. A phase shift towards an algae-dominated system may accompany coral loss. In this case, the composition of the reef-associated fish assemblage will change and human communities relying on reef fisheries for income and food security may be negatively impacted. We present a case study based on the Raja Ampat Archipelago in Eastern Indonesia. Using a dynamic food web model, we simulate the loss of coral reefs with accompanied transition towards an algae-dominated state and quantify the likely change in fish populations and fisheries productivity. One set of simulations represents extreme scenarios, including 100% loss of coral. In this experiment, ecosystem changes are driven by coral loss itself and a degree of habitat dependency by reef fish is assumed. An alternative simulation is presented without assumed habitat dependency, where changes to the ecosystem are driven by historical observations of reef fish communities when coral is lost. The coral-algal phase shift results in reduced biodiversity and ecosystem maturity. Relative increases in the biomass of small-bodied fish species mean higher productivity on reefs overall, but much reduced landings of traditionally targeted species. [ABSTRACT FROM AUTHOR]