PELEPASAN DENSITAS Zooxanthellae KARANG Acropora sp. PADA BEBERAPA TINGKAT SALINITAS

Abstract

Coral reef ecosystems are strongly influenced by marine environment factors, one of which is salinity. The effect of high salinity (hipersalin) and low salinity (hiposaline) on corals causes osmotic stress so that zooxanthellae will come out of polyps may cause bleaching and coral death in long-term exposure. The purpose of this study is determining the effect of several salinity concentrations on zooxanthellae density and their relationship to photosynthesis (NPP), respiration and primary productivity (GPP). This research used experimental method was conducted on November 13 – February 7, 2020 at Coastal Development Laboratory (LPWP). Corals used as research objects are Acropora sp. taken from the waters of Pulau Panjang, Jepara. Acropora sp. is given salinity concentration treatment (25 /oo, 30 /oo, 35 /oo). Observations were made at 0, 3, 6 and 9 day time intervals. The results showed that the difference in salinity concentration significantly affected the density of zooxanthellae. Salinity concentration 25 /oo treatment causing the highest zooxanthellae release pressure with a decrease of 21 animals per day. Zooxanthellae density affects the value of photosynthesis (NPP), respiration and gross primary productivity (GPP) of corals. The lower the zooxanthellae density, the lower the NPP, respiration and GPP of corals tends to be.