The definition of anthropogenic is from human sources and with global populations growing rapidly there have been increased impacts upon reefs (Hughes et al., 2003). Anthropogenic impacts occur at a local scale. Isolated reefs, such as the Chagos Archipelago, in the Indian Ocean, escape from these effects and remain in a much healthier state (Guitart et al., 2007). The anthropogenic damage comes from several sources, explained in this section:
1. Eutrophication: the effect of increased nutrients from agricultural runoff and sewage pollution.
2. Fishing: damage is due destructive fishing techniques and the removal of species.
3. Tourism: how the increase in the number of visitors on the reef damage the coral, through diving, anchoring and the effects of development.
Human impact can weaken the resilience of the reefs meaning that weak reefs will be more prone to the effects of the changing climate (Hughes et al., 2003).