Microplastic pollution in water is harmful to aquatic life and can affect human health. A study looked at how three types of microplastics move through the food chain from algae to small water fleas to fish. They found that the microplastics with carboxylate and amine groups accumulated more than regular polystyrene microplastics. The highest concentration of microplastics in the fish was seen after 24 hours. The microplastics mainly gathered in the fish's intestines, showing that they build up along the food chain. This study confirms that microplastics can move up the food chain and accumulate in fish, which could have implications for human health.