Kematian alami karang di Laut Jawa

NATURAL DEATH OF CORALS IN JAVA SEA. Bleaching and death of hermatypic coral was observed in the Java Sea at the end of the west monsoon i.e. from March to May 1983. This phenomenon occurred in extensive area, from the coast of Banten (West Java) to Seribu Islands (off Jakarta) and Karimun jawa Islands (Central Java). The dead corals were seen as white patches on the reef flat down to about 15 meter depth. In selected area of 50 m2, the percent cover of the discoloured corals appeared to be 40 - 50% and the dead ones about 10 - 15%. In the middle of May the corals death in the same area increased to 80 - 90% and by the end of July they ceased increasing and some of the colonies seemed to recover. The corals affected were scleratinian, hydrocorals (Millepora) and soft corals. A total of 72 species of scleractinians comprising of 33 general were affected. Histological observation on the discoloured coral tissue (endoderm) showed little or no endosymbiotic algae (zooxanthellae) which are abundant in the normal tissue. The primary cause of this disaster is not yet clear. The increase of water temperature is suspected to be one of the cause.