Search

Debates on the role of coral reefs, whether as a carbon source or carbon sink, started in the early 1990s. These debates continue until today, especially with the increasing concern of global climate change and global warming. Although several studies have been done to calculate the flux of pCO2 between reefs and the atmosphere, there is no clear evidence whether the coral reef is a source or sink. This paper reviews the development of studies of carbon flux of reefs, with how pCO2 is different in several reef type habitats and assess if geographical latitude of reef affected the flux of CO2. In general, coral reefs act as a carbon source to the atmosphere. However, this role depends on the habitat type of reef, whether they are coral-dominated or algal-dominated reef. The geographical location of reefs may also affect CO2 flux between reefs and the atmosphere. [ABSTRACT FROM AUTHOR]

Coral recruitment is a critical component in the management of coral reefs. Coral recruitment is the main factor in the recovery of the coral ecosystem, because of the addition of new individuals. The high recruitment of corals is an indication of natural recovery in the reef community. This study aims to determine the density of coral recruitment in Gili Pandan Island at a depth of 3 meters and 8 meters. Two sites were used as a sampling site. Juvenile corals with diameters less than 5 cm were observed in quadratic transects with 1x1 meter sizes randomly and performed with ten repetitions at each point. Coral density was calculated for the determination of recruitment rates. T-test was used to determine whether there is a difference in coral recruitment between 3 and 8 meters in depth. The results showed that the average density of coral recruitment of site 1 and site 2 at a depth of 3 meters was 5.9-7.6 individual/m², categorized as high recruitment, while at a depth of 8 meters were 3.3-4.3 individual/m², categorized as low recruitment. T-test results showed that there is a significant difference in coral recruitment density between 3 and 8-meter depth both at sites 1 and 2. [ABSTRACT FROM AUTHOR]

Gili Labak has an excellent coral reef condition but has many problems, including coral disease. This study aims to identify bacteria that are associated with Acropora Formosa corals, which have the potential as antibacterial white plague disease in Acropora sp. The method used in the antibacterial test is the overlay test and agar diffusion test and laboratory analysis using bacterial isolation, DNA extraction, DNA amplification, sequencing, and phylogenetic analysis. Based on bacteria morphology, four bacterial isolates were found from healthy Acropora, namely AF1, AF2, AF3, and AF4. From the results of the antibacterial activity test using the pathogenic bacterium Bacillus Firmus, isolates AF1 produced an inhibitory zone in three days of 5.10 ± 0.10 mm, 2.7 ± 0.04 mm, and 3.80 ± 0.02 mm, respectively, while AF3 produced an inhibitory zone of 2.90 ± 0.16 mm, 3.10 ± 0.06 mm, and 2.7 ± 0.11 mm, respectively. Meanwhile, the antibacterial activity test using pathogenic bacteria Bacillus dretensis, AF2 produced an inhibitory zone of 3.80 ± 0.01 mm, 2.20 ± 0.15 mm, and 1.30 ± 0.09 mm, respectively, while AF4 produced an inhibitory zone of 4.60 ± 0.060 mm, 2.90 ± 0.06 mm, and 1,00 ± 0.06 mm, respectively. The results showed that all isolate from healthy Acropora formosa had potential antibacterial activity against bacteria of white plague disease. The phylogenetic analysis showed that AF1, AF3, and AF4 had 99% similarity with Virgibacillus salarius, and AF2 had 98% similarity with Halomonas sp. [ABSTRACT FROM AUTHOR]