Microplastics in tropical coastal areas host a wide variety of plankton, including harmful species like dinoflagellates. By studying beach sediments in the Johor and Singapore Straits, researchers found that microplastics provide a suitable environment for diverse plankton communities. The most polluted site had the highest plankton diversity, with dinoflagellates, fungi, and chlorophytes dominating the communities. This shows that microplastics can transport toxic plankton species in marine environments, highlighting the impact of human activities on marine ecosystems.