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Coral reef is an ecosystem which provides suitable habitats for sgroups of biota that has important ecological and economic values which can be used as bio-indicators to assess the health of the environment. Research on megabenthic fauna in Kendari waters and its surroundings, Southeast Sulawesi was carried out at nine permanent stations in 2015 to 2018. The data was collected using the Benthos Belt Transect method that modified from the Belt Transect method on 8 types or groups of megabenthos in these waters. The purpose of this study was to determine the density fluctuation of megabenthic fauna over the years. The mean density of individuals found at each station during the study did not differ significantly. The Kruskal-Wallis test on density of megabenthic fauna during this period of times did not show a significant difference (H = 28.511 > df 7 = 14.067). Drupella spp. was the group species of megabenthic fauna with the highest density each year (1,079-1,738 ind/ha), while lobster was the group species of megabenthic fauna with the lowest density each year (0 - 39.7 ind/ha). The crown of thorns starfish Acanthaster planci had the highest fluctuation where density increased from 28.3 to 71.4 ind/ha.

IDENTIFIKASI BAKTERI PATOGEN PENYEBAB PENYAKIT PURPLE SYNDROME PADA KARANG FUNGIA DI PULAU HARI SULAWESI TENGGARA Nowadays coral disease is one of the causes of damage to coral reefs in Indonesia. Causative agents were found for some types of coral disease. This study aims to identify the type of pathogenic bacteria that cause purple syndrome which attacks Fungia corals. The study was conducted using descriptive exploratory methods. Corals infected with purple syndrome were collected on Pulau Hari, Southeast Sulawesi, through scuba diving. Then, microbiological analysis was carried out which included isolation using the scatter method, purification using a scratch method, a challenge test (antagonistic), a Koch Postulate test, and DNA analysis of putative bacterial isolates. Results showed that 5 bacterial isolates lived in symbiosis with the corals infected with purple syndrome (PSMH1, PSMH2, PSMH3, PSMH4, and PSMH5). Based on the Koch postulate test, 2 bacterial isolates which were pathogenic were obtained, namely PSHM2 and PSHM4 isolates. These bacteria infected the test corals with the characteristics of coral skeleton damage and coral bleaching (dead). Based on biomolecular testing, the two isolates were members of Enterobacter cloacae with a 99% similarity level.Keywords: Coral disease; Enterobacter cloacae; Fungia coral; Hari island; Purple syndromeABSTRAKSaat ini penyakit karang menjadi salah satu penyebab kerusakan terumbu karang di Indonesia. Penyebab pembawa untuk beberapa jenis penyakit karang sudah ditemukan. Penelitian ini bertujuan untuk mengidentifikasi jenis bakteri patogen penyebab penyakit purple syndrome yang menyerang karang Fungia. Penelitian dilakukan menggunakan metode deskriptif eksploratif. Sampel karang yang terinfeksi purple syndrome diambil di Pulau Hari, Sulawesi Tenggara, melalui scuba diving. Selanjutnya, analisis mikrobiologi dilakukan yang meliputi isolasi menggunakan metode sebar, purifikasi menggunakan metode gores, uji tantang (antagonistik), uji Postulat Koch, dan analisa DNA isolat bakteri yang diduga bersifat patogen. Hasil penelitian menemukan 5 isolat bakteri yang bersimbiosis dengan karang yang terinfeksi penyakit purple syndrome (PSMH1, PSMH2, PSMH3, PSMH4, dan PSMH5). Berdasarkan uji postulat Koch, 2 isolat bakteri yang bersifat patogen didapatkan, yaitu isolat PSHM2 dan PSHM4. Bakteri tersebut menginfeksi karang uji dengan ciri kerusakan skeleton karang dan pemutihan karang (mati). Berdasarkan uji biomolekuler kedua isolat tersebut merupakan anggota Enterobacter cloacae dengan tingkat kemiripan 99%.