Metal content of Gracilaria changii originating from different seaweed cultivation areas in South Sulawesi, Indonesia

Food safety is one of the crucial issues in aquaculture. The metal waste from various activities on land can enter the waters and accumulate in aquaculture products, such as seaweed. This study aimed to examine the metal content of seaweed Gracilaria changii. This study covered three marine areas around South Sulawesi, namely the Gulf of Bone, the Flores Sea and the Makassar Strait, while seaweed samples were taken from four seaweed cultivation locations (Regencies of Bone, Sinjai, Takalar and Pangkep). The heavy metal concentrations analyzed were copper (Cu), cadmium (Cd), and lead (Pb). The results showed that Cu concentrations in G. changii were greater than that in the sea water, but the difference was not significant (P>0.05). Cd concentrations in G. changii were significantly greater than that in the sea water (P<0.05), while the Pb concentrations in the seaweed were smaller than in the sea water, but not significantly different (P>0.05). G. changii was able to accumulate metals, but its accumulation ability was inconsistent. The Cu, Cd and Pb may accumulate or be released back into the surrounding sea water, which is an advantage from a food safety point of view. Despite the accumulation of Cu, Cd and Pb in G. changii thallus, these metals are likely to be released back during the G. changii processing as food or when products are stored as food or feed.