Pb heavy metal distribution patterns in seaweed (Kappaphycus alvarezii) cultivation locations by season in Bantaeng Waters, South Sulawesi

Abstract

Heavy metals found in the waters can be absorbed and accumulated in the seaweed thallus. Heavy metals affect plants by changing the position of essential ions in cells. Seaweed is useful in absorbing heavy metals so that the heavy metals contaminating the water can enter the seaweed thallus. This research was conducted at the seaweed cultivation location in the coastal waters of Bantaeng Regency, South Sulawesi. The method used is a survey and laboratory testing. Each location is determined by 3 substations (short, medium, and long-distance). Water and seaweed sampling at each station are carried out twice a month. Pb heavy metal analysis from water and seaweed samples was carried out in the laboratory of the Faculty of Mathematics and Natural Sciences of Hasanuddin University. Distribution pattern of Pb heavy metal content with spatial analysis of Geographic Information Systems (GIS) based on a mapping approach. The results showed that the concentration of Pb heavy metals in waters during the rainy season ranged from 0.25 to 0.98 ppm and during the dry season ranged from 0.20 to 1.13 ppm, whereas seaweed in the wet season ranged from 4.64 to 7.00 ppm and in the dry season ranged from 1.20 to 20.87 ppm. Pb heavy metal distribution patterns in waters and seaweed are high in areas close to the coast and low in areas far from the coast. The average concentration of Pb heavy metals in waters and seaweed is higher in the dry season than in the rainy season. The content of Pb heavy metal in water has exceeded the threshold for the designation of fishery water 0.08 ppm (KEP. MENLH N0 51, 2004). The content of Pb heavy metals in seaweed has passed the threshold for food 2.0 ppm.