Water quality study in several seaweeds culture sites in the post-earthquake-tsunami Palu Central, Sulawesi Province

On September 28, 2018 the Palu City and its surroundings experienced an earthquake of M 7.4 and Tsunami. This incident had a major impact on the community, especially seaweed farmers. The study aims to determine the effect of water quality on the production of seaweeds (Kappaphycus alvarezii and Spinosum sp) post-earthquake-tsunami in Central Sulawesi. This study are located Parigi Moutong and Donggala Regency. The research variables were observed include quality of the seawater and seaweeds production before-after the earthquake-tsunami Palu. Suitability of seaweed culture identification using Principal Component Analysis (PCA). The results showed that the location most suitable seaweeds culture is at a spacing of 300-500 meters from the river mouth while the water quality such as temperature, salinity, brightness, depth, dissolved oxygen, pH, surface current, pH, phosphate, nitrate, TDS and TSS, still within acceptable limits for the growth and production of seaweeds. Gracilaria sp. can no longer becultivated after an earthquake disaster due to the pond water quality not supporting its growth. Spinosum sp is more cultivated than Kappaphycus alvarezii in Parimo and Donggala, with a decrease in seaweeds production 50-60% after the earthquake-Tsunami Palu.