Chronic overfishing was not immediately recognized as a threat by coral reef researchers (Hughes, 1994). However, growing coastal populations and their associated consumption of seafood has driven fisheries down the food chain from larger predatory species like snappers, triggerfish, and groupers, to smaller herbivorous reef grazers like parrotfish and sturgeonfish (Hughes, 1994).

Overfishing of grazers can upset the balance of coral reef system with the following consequences (Hughes, 1994):

• Less grazing of macroalgae

• Increased competition with zooxanthellae for sunlight

• Decreased reef growth rate

• Increased risk of phase shift from a coral dominated system to an algal dominated system

• Increased susceptibility to other stressors