Tire reefs especially when combined with concrete rubble are very effective here in NJ waters where most of the sea bottom is mud or sand - kinda like anoasis in the middle of the desert ofr marine life - fish, crabs, lobster, etc. However I could see where damage would be done to an area of natural reef that would be nearby - not too bright. Also amazing to look at those shots with no signs of marine life after all those years - here grasses, barnacles and mussells grow with 12 months and migratory fish will move in almost immediately. Problem with tires here is that they get covered up by sand over the course of a few years and disappear, so the Reef Commitees in New Jersey have opted for old boats, ships and concrete rubble.