Abstract: The present invention uses fish bones and fish hard parts to remediate, clean-up, stabilize, immobilize, or otherwise treat metal-contaminated water, soil or waste of any sort. The fish bones and fish hard parts can be mixed in with soils and wastes, or emplaced as a permeable reactive barrier in a trench or excavation, or emplaced as a liner or barrier surrounding a waste form, disposal site, or contaminated site. All that is needed is intimate contact between the fish bones and fish hard parts and the contaminated waste form, soil particles, or water. In a system of, for example, soil, waste, groundwater, surface water, waste streams, or the digestive tracts of animals, the presence of fish bones and fish hard parts reduces the amount of metal that can mobilize and migrate out of the system. Fish bones and fish hard parts remove metals from waters passing through the system or originating within the system.