Figure 4.

Parrotfishes play critical roles in coral reef ecosystems. (a) The giant humphead parrotfish (Bolbometopon muricatum) is a major external bioeroder and coral predator on Indo-Pacific reefs. Despite its critical functional roles, as a large species it is one of the first to be depleted by fishing. (b) Smaller-bodied parrotfish species such as Scarus schegeli are able to maintain their ecosystem role as grazers in the face of intensive fishing pressure. (c) Fishing activity such as spearing is highly selective, thereby affecting some ecosystem functions more than others. (d) Artisanal fishing of small parrotfishes may be sustainable in the short-term but the reefs that support them are increasingly vulnerable to loss of ecosystem functions (photos: (a,b) J. P. Krajewski; (c) J. Kritzer; (d) D.R.B.).