While many parrotfishes are able to survive human fishing activities on coral reefs, the giant humphead parrotfish (Bolbometopon muricatum) is highly sensitive to fishing pressure. With the loss of this species ecosystem processes on coral reefs are fundamentally changed. Photos J.P. Krajewski.

The bridled parrotfish (Scarus frenatus) is one of many small parrotfish species that graze the algal-covered reef surface. Unlike its larger relatives this species can withstand some human fishing pressure. Through its grazing activity it can buy time reefs while we confront the coral reef crisis. Photo J.P. Krajewski.

Smaller-bodied parrotfish species such as Scarus schegeli are able to maintain their ecosystem role as grazers in the face of intensive fishing pressure. Photo J.P. Krajewski.

Fishing activity such as spearing is highly selective, thereby affecting some ecosystem functions more than others. Photo J. Kritzer.

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. Photo D Bellwood

Free copyright is granted for use of these images in conjunction with ARC Centre of Excellence news stories