Trading with resilience: Parrotfish trade and the exploitation of key-ecosystem processes 

Publication review

Parrotfish play two important roles in coral reef social—ecological systems; first as important sources of food for reef dependent people, and second by underpinning the ecological function of herbivory (i.e., grazing of algae) on coral reefs.

Overfishing of herbivores can be detrimental to coral reef ecosystems because their removal may allow algae to outcompete corals. However, little is known about the drivers behind the exploitation of parrotfish.

We describe the trade of parrotfish in Zanzibar with the aim to visualize the linkages between ecological function, market price, and socioeconomic drivers behind their exploitation. Three interesting findings emerge. First, parrotfish are an important part of the fish trade in Zanzibar and are traded at all market scales (from local consumers to international tourists). Second, size is an important determinant of price, with larger fish generating much higher values. Third, size determines which market parrotfish are sold to. Overall the study shows that all sizes of parrotfish are exposed to exploitation, leaving no size-refuge for escaping harvest.

In light of an increasing global demand and high market prices, we thus propose that traditional fisheries management be complemented with assessments of both ecological understanding and socioeconomic dynamics to take into account of global market drivers behind parrotfish exploitation at local scales.