Are there differences between the types of artificial reef materials?
Top Yes, different materials have different chemical and physical properties which can effect the life that grows on them and can even determine what kind of life can grow on them. Some materials are known to be toxic to marine life (which is why ships must be cleaned very well before they are made into artificial reefs) and some are known to provide nutrients which (unnaturally) enhance growth. Chemicals that cause toxicity or enhance growth can be leached (gradually released) from some artificial reef materials and effect the colonization of life onto the reef. Also, the physical characteristics, such as size of crevices present or created, and shape of the artificial reefs can effect marine life colonization. Another difference is that some materials fall apart quickly in sea water or are unstable on the ocean floor, which can prevent the colonization of life. There is much debate as to whether certain materials are better or worse than others.
