Colonization of Coral Communities in the Krakatau Islands Strict Marine Nature Reserve, Indonesia

Krakatau Islands diversity is geomorphologically dynamic, and these physical changes influence on organisms including community successional. The purposes of this research were to determine the condition and describe the recent colonization development of coral communities in the Krakatau Islands after sterilization. Transects were done at six stations at two different depth (i.e. 5 and 10 m) using line intercept transect. While observations of coral communities were done with video transect. This study showed that succession or development of coral communities (i.e. colonization) that found in Anak Krakatau indicated earlier stage of colonization. It has different coral communities compared with those that found in Rakata and Panjang island. The diversification of coral communities on both islands, showed that opportunistic and pioneer species (i.e. Pocillopora and Seriatopora) that generally found in Anak Krakatau has been replaced. There are indications of dominance may already take place through competitive exclusion in the coral communities. Three community types were distinguished based on characteristics for each sites, as follows: communities of wave-exposed habitats, communities of semi- exposed to sheltered habitats, and communities of sheltered habitats. The extent of coral damage covered all six sites based on coral damage index (CDI). This suggests that of the all transects were hot spots that required management action. These results indicate that colonization and the level of coral damage have to be taken into account on the manegement of coral ecosystem in the region.