The conservation status of 845 zooxanthellate reefbuilding coral species have been assessed using IUCN Red List Criteria. Of the 704 species that could be assigned conservation status, 32.8% are in categories with elevated risk of extinction. Declines in abundance are associated with bleaching and diseases driven by elevated sea surface temperatures, with extinction risk further exacerbated by local-scale anthropogenic disturbances. The proportion of corals threatened with extinction has increased dramatically in recent decades and exceeds most terrestrial groups. The Caribbean has the largest proportion of corals in high extinction risk categories while the Coral Triangle (western Pacific) has the highest proportion of species in all categories of elevated extinction risk. Our results emphasize the widespread plight of coral reefs and the urgent need to enact conservation measures.Coral reefs harbor the highest concentration of marine biodiversity. They have high esthetic, recreational and resource values that have prompted close scientific scrutiny, including long-term monitoring (1, 2) and face increasing threats at local and global scales. Globally, rapid build-up of carbon dioxide (and other greenhouse gases) in the atmosphere is leading to both rising sea surface temperatures (with an increased likelihood of mass coral bleaching and mortality) and acidification (8). Ocean acidification is reducing ocean carbonate ion concentrations and the ability of corals to build skeletons (9). Local threats include human disturbances such as increased coastal development, sedimentation resulting poor land-use and watershed management, sewage discharges, nutrient loading and eutrophication from agrochemicals, coral mining, and over fishing (1-7). Local anthropogenic impacts reduce the resilience of corals to withstand global threats, resulting in a

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Abstract. The 2015–2016 El-Niño and related ocean warming has generated significant coral bleaching and mortality worldwide. In Indonesia, the first signs of bleaching were reported in April 2016. However, this El Niño has impacted Indonesian coral reefs since 2015 through a different process than temperature-induced bleaching. In September 2015, altimetry data show that sea level was at its lowest in the past 12 years, affecting corals living in the bathymetric range exposed to unusual emersion. In March 2016, Bunaken Island (North Sulawesi) displayed up to 85 % mortality on reef flats dominated by Porites, Heliopora and Goniastrea corals with differential mortality rates by coral genus. Almost all reef flats showed evidence of mortality, representing 30 % of Bunaken reefs. For reef flat communities which were living at a depth close to the pre-El Niño mean low sea level, the fall induced substantial mortality likely by higher daily aerial exposure, at least during low tide periods. Altimetry data were used to map sea level fall throughout Indonesia, suggesting that similar mortality could be widespread for shallow reef flat communities, which accounts for a vast percent of the total extent of coral reefs in Indonesia. The altimetry historical records also suggest that such an event was not unique in the past two decades, therefore rapid sea level fall could be more important in the dynamics and resilience of Indonesian reef flat communities than previously thought. The clear link between mortality and sea level fall also calls for a refinement of the hierarchy of El Niño impacts and their consequences on coral reefs.

Indonesia is part of the coral triangle region which is known as the world’s highest marine biodiversity, including stony corals. This situation used to benefit local people by trading ornamental corals. The aims of this study are to investigate the potential stock of ornamental corals as well as the reef conditions. The study took place in Kendari, Luwuk, Sumbawa and Belitung where the ornamental coral-collecting activities used to occur. The result indicates there were approximately 110 species of corals found with the majority of coral status are common (harvest limited) and uncommon (harvest with cautions). Based on the juvenile existence, only 66 corals have potential stocks. Euphyllidae (Euphyllia glabrescens and Plerogyra sinousa) had the highest potential stock in Kendari and Luwuk, while Fungiidae (Fungia spp) held the highest potential stock in Belitung and Sumbawa. This difference is likely related to different locality or habitat type. In general, coral reefs in Kendari, Luwuk and Belitung are in good condition, while fair condition occurs in Sumbawa. To conclude, the stock of ornamental corals is still high and the reefs are generally good, suggesting the collecting activities may be allowed with proper quota and continuous monitoring habitat condition to ensure the sustainability.

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<p><strong>Abstract.</strong> The 2015–2016 El-Niño and related ocean warming has generated significant coral bleaching and mortality worldwide. In Indonesia, first signs of bleaching were reported in April 2016. However, this El Niño has impacted Indonesian coral reefs since 2015 through a different process than temperature-induced bleaching. In September 2015, altimetry data shows that sea level was at its lowest in the past 12 years, affecting corals living in the bathymetric range exposed to unusual emersion. In March 2016, Bunaken Island (North Sulawesi) displayed up to 85 % mortality on reef flats dominated by <i>Porites</i>, <i>Heliopora</i> and <i>Goniastrea</i> corals with differential mortality rates by coral genus. Almost all reef flats showed evidence of mortality, representing 30 % of Bunaken reefs. For reef flat communities which were living at a depth close to the pre-El Niño mean low sea level, the fall induced substantial mortality likely by higher daily aerial exposure a least during low tide periods. Altimetry data was used to map sea level fall throughout Indonesia, suggesting that similar mortality could be widespread for shallow reef flat communities, which accounts for a vast percent of the total extent of coral reefs in Indonesia. The altimetry historical records also suggest that such event was not unique in the past two decades, therefore rapid sea level fall could be more important in the dynamics and resilience of Indonesian reef flat communities than previously thought. The clear link between mortality and sea level fall also calls for a refinement of the hierarchy of El Niño impacts and their consequences on coral reefs.</p>

Black band disease (BBD) is the oldest recognised disease associated with scleractinian corals. However, despite this, few BBD surveys have been conducted in the Indonesian archipelago,one of the world’s hot spots for coral diversity. In this study, we show that BBD was recorded in the reefs of Kepulauan Seribu, Indonesia, at the time of surveying. The disease was found to mainly infect corals of the genus Montipora. In some instances, upwards of 177 colonies (31.64%) were found to be infected at specific sites. Prevalence of the disease ranged from 0.31% to 31.64% of Montipora sp. colonies throughout the archipelago. Although BBD was found at all sites, lower frequencies were associated with sites closest to the mainland (17.99 km), as well as those that were furthest away (63.65 km). Despite there being no linear relationship between distance from major population centers and BBD incidence, high incidences of this disease were associated with sites characterized by higher levels of light intensity. Furthermore, surveys revealed that outbreaks peaked during the transitional period between the dry and rainy seasons. Therefore, we suggest that future surveys for disease prevalence in this region of Indonesia should focus on these transitory periods

Sumberdaya rumput laut alam yang berlimpah di perairan Indonesia merefleksikan besarnya potensi penyerapan karbon oleh rumput laut untuk mengurangi gas rumah kaca, CO2, yang merupakan salah satu faktor penyebab terjadinya fenomena perubahan iklim. Penelitian ini bertujuan untuk menganalisis potensi serapan karbon oleh rumput laut alam di kawasan pesisir Labuhanbua, Kabupaten Sumbawa, NTB dan Ujung Genteng, Kabupaten Sukabumi, Jawa Barat. Pengumpulan data lapangan berdasarkan titik-titik pengamatan yang disebar pada transek garis yang tegak lurus terhadap garis pantai; meliputi data luas tutupan, jenis, dan kandungan karbon rumput laut alam yang dominan ditemukan pada kedua lokasi penelitian. Hasil penelitian menunjukkan bahwa jenis-jenis rumput laut yang ditemukan di kawasan pantai Ujung Genteng terdiri atas 36 spesies dan di Labuhanbua 28 spesies. Berdasarkan besarnya simpanan karbon dalam bentuk biomassa pada berbagai spesies rumput laut alam di kedua lokasi penelitian, maka Sargassum sp., Padina sp., Dictyota dichotoma, Hydroclathrus clatratus, Gracilaria sp., G. foliifera, G. salicornia, Gelidium sp., dan Turbinaria sp., merupakan spesies potensial yang berperan sebagai media penyimpanan karbon biru, dan semua jenis tersebut dapat dikembangkan melalui aktivitas budidaya.