Plastic waste in water breaks down into tiny pieces called microplastics, which can harm aquatic animals like Daphnia magna. When nickel, a heavy metal, mixes with microplastics, it can be even more toxic to these tiny creatures. In this study, scientists tested two types of microplastics with different properties and found that the combination of nickel with microplastics affected Daphnia magna differently than nickel alone. They discovered that Daphnia magna exposed to nickel with a carboxyl group-coated microplastic were more affected than those exposed to nickel with a different type of microplastic. This shows that the type of microplastic and pollutant can change how harmful they are when mixed together. More research is needed to understand how different combinations of microplastics and pollutants affect aquatic life.