Colonization of Coral Communities in the Krakatau Strict Marine Nature Reserve, and Management Implications

Abstract

The eruption and near-total destruction of the volcano Krakatau on the 26 – 28 August 1883 was completely exterminating all ecosystems life in the Krakatau Islands and surrounding area (i.e. Sebesi, Sebuku and Legundi). After three months of minor activity, that catastrophic eruption destroyed over two thirds of Krakatau, only a fraction of Rakata remaining. The islands diversity is geomorphologically dynamic, and the effects of physical changes on the biota, and on the rate of successional turnover, are considerable interesting. In addition, the islands discrete, definable, tropical biota provides a rare opportunity for ecological studies, particularly of communities interactions that has develop in this area. The purposes of this research were to determine the condition and describe the colonization development of coral communities in the Krakatau Islands after total destruction, including disturbances from natural environment. Benefit was to provide amount recent information of composition, distribution, and structure of coral communities in the Krakatau Islands. Also for explain the extent of coral damage, and the implications for management of coral reefs in the Krakatau Strict Nature Reserve. This study showed that succession or development of coral communities (i.e. colonization) that found in Anak Krakatau indicated earlier stage of colonization. Where have different with coral communities that found in Rakata and Panjang. 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. Lifeform of coral communities found varied between sites, where sub-massive is dominated lifeform that found in Anak Krakatau, but massive and branching lifeform are more dominant in Rakata and Panjang. There are indication of dominance may already take place through competitive exclusion in 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 that found in Krakatau based on CMI value is low, in average, but high value found in the community of wave-exposed habitat. While, following CDI criteria, the extent of coral damage covered all six sites. This suggests that of the all transects were "hot spots'' that required management action. Although Krakatau Strict Marine Nature Reserve has been declared part of Ujung Kulon National Park in 1983, it is not managed as such because it falls under a different province. Furthermore, it has been managed subsequently by BKSDA Lampung since 1990.