Phytoplankton in the coastal waters of South Sulawesi were studied to see how they are affected by pollution. Researchers found 31 different species of phytoplankton, with some being harmful when they grow too much. The abundance and types of phytoplankton varied between different areas and rivers. Pollution levels were linked to the amount of one type of phytoplankton called Dinophyceae. One harmful species, Ceratium furca, had a big impact on the diversity of phytoplankton, reducing the number of different species present. Overall, the study showed that pollution can change the types and amounts of phytoplankton in coastal waters.