Artificial coastlines, including human-made dikes and other engineered constructions, can help prevent erosion and protect from storms and flooding. However, ecological functions remain unprotected from many of these structures. So researchers in China have investigated the use of specialized types of cement. The team started with a limestone and clay cement that hardens underwater and then added polyacrylamide and chitosan. The two treatments were mixed into the cement to form the hardened substrate, and they were sprayed onto previously hardened cement as a surface treatment. After two days, biofilm was found active and growing well on the surface-treated samples.