Many scientists believe that artificial reefs are likely to create more problems than benefits. First, the fact that more fish are reported as being caught near artificial reefs doesn't necessarily mean that overall populations of fish have grown larger. Remember how reefs work, wreaths attract fish to them, right? This means that fish that once lived in more distant locations have moved to and stay near these reefs. So the higher catch numbers may simply mean that the reefs have attracted a lot of fish that once lived somewhere else. In fact, by attracting a lot of fish to a single location, artificial reefs may cause a decrease in fish populations because they help fishers to catch so many fish that the fish cannot maintain their populations. Second, it's a bad idea to allow small scale fishers to create artificial reefs in secret locations and not tell other people where they are. Not knowing where the reefs are can cause all kinds of safety problems. For example, other fishers who use large nets to catch fish can get their nets caught on reefs and destroyed as a result. In shallow waters, boats might even crash into secret reefs. Now, the only way artificial reefs can be made safe is to make their locations known, but when relocations are public, small scale fishers have no competitive advantage in using those reefs. Finally, artificial reefs can cause serious environmental damage, even when harmful chemicals have been removed from them. This happened to the Osborne reef. The Osborne reef was an artificial reef made of used car tires. The tires were bound together, but when a storm came, parts of this artificial reef came loose and started crashing into the surrounding sea floor. The loose parts of the Osborne reef, propelled by the force of the storm, caused a lot of environmental damage, harming many marine plants and animals living on the sea floor.