Rekrutmen Karang pada Substrat Batu di Gosong Pramuka, Kepulauan Seribu DKI Jakarta

Abstract

Gosong Pramuka is an area of coral reefs in the center of the Kepulauan Seribu region economy. The existence of the stony substrate around Gosong Pramuka as a potential habitat for coral larval settlement. Research aims to determine the recruitment of coral stony substrate in the Gosong Pramuka, Kepulauan Seribu. Research was conducted from April to June 2013 at Gosong Pramuka, comprising four stations: Exposed I, Exposed II, Sheltered I, and Sheltered II. Observations were conducted by observing all surface of stony substrate for coral recruits. Each coral recruits were vertically photographed using underwater camera with macro setting, thus identified until genus level. Images of coral recruit were processed by Image J to measure coral diameter and width. There were 95 colonies of coral recruits with the largest number of colony observed at Station Exposed I (35 colonies) belonging to Acropora and Porites. Lifeform of coral recruit for Acropora comprised of branching, digitate, tabulate and encrusting, while for Porites was massive and submassive. Average width of coral recruit was 25-50 cm2, while average diameter was 9-12 cm. Average index of coral health was 2-3, referring to CoralWatch method, indicating stressed colonies. Density of coral recruit for Station Exposed I was 0.22 colony/m2, Sheltered I 0.11 colony/m2, Exposed II 0.13 colony /m2 and 0.11 colony /m2 at Sheltered II. Correspondence analysis revealed that the presence of Porites coral recruit was influenced by depth, salinity, pH, temperature, while Acropora by distance from reef/stone bottom. Average diameter and width of coral recruits were closely associated with orthophosphate. Diameter of coral recruit was closely affecting the coral width.