Mussel can purify water. Mytilus edulis is considered as a natural purifying agent for aquatic organisms, which has a certain effect on cleaning up toxic and harmful substances in water. Its main principle is to purify water quality and improve water ecological environment by ingesting or adsorbing refractory organic substances such as wastes, parasites, bacteria and algae in water. In addition, mussels can secrete a lot of clear mucus, which makes pollutants adhere to their surfaces, which is helpful to filter, decompose and absorb pollutants in water.