Our project aims to engineer ostreococcus, a a strain of filamentous algae, to absorb microplastics, efficiently retain them, and then produce luminescence to indicate that absorption of microplastics is complete. The algae would also be altered so as to prevent rapid reproduction and mitigate the formation of harmful algal blooms. Once the engineered algae has served its function and outputs its signal, the algae would be removed from the water body and the high microplastic concentration along with it.