Why do fishers fish where they fish? Using the ideal free distribution to understand the behaviour of artisanal reef fishers

We used the theory of the ideal free distribution (IFD) as a framework to understand the mechanisms underlying fishing site selection by Anguillian artisanal fishers exploiting shallow-water coral reefs. Contrary to the predictions of IFD, fishers did not distribute themselves so that average reward was equal among fishers using different fishing methods or among fishers using the same method. In addition, fishing pressure did not increase with resource availability. Key assumptions of the IFD were not met. The distribution of Anguillian fishers was not "ideal" because lack of knowledge prevented fishers from choosing fishing grounds with the greatest rewards. Not all fishers sought to maximise profit. In addition, all fishers were not "free" to distribute themselves among reefs owing to variation in social, economic, and physical characteristics of fishers that constrained fisher movements and ability to extract resources. This study shows that as a null model the IFD is useful to frame studies designed to gain detailed insights into the complexity and dynamics of a small-scale fishery. Alongside ecological data, this framework may inform efficient and effective development of reef and fishery management practice.