ing coral communities it is likely that human intervention is a cause for reef degradation In the case of change that seems related to past cycles, natural causes are a likely cause Neither of these cases can provide a sure distinction between causes, and in some cases both causes may be present 31Referenceshttp//en.wikipedia.org/wiki/Great_Barrier_Reef http//www.reefhq.com.au/ Van Woesik, R., Don