Qualitative analysis of recreational fisher response and the ecosystem impacts of management strategies in a data-limited situation

The behavioural responses of recreational fishers to changes in fisheries management are rarely investigated and as a result may be poorly understood. Changes in fisher behaviour following the introduction of new management strategies can generate unexpected outcomes, such as a shift towards targeting alternative species. Such changes can create new problems for management but even basic data are rarely available to predict the impacts of behavioural changes. Qualitative modelling can be a useful technique in data-limited situations to investigate potential shifts in management problems. This technique was used to investigate the effects of changes in fisher behaviour following the implementation of a seasonal fishing closure on a suite of high-value demersal scalefish. A simple ‘core’ model was used to investigate the dynamics involved in the general management of recreational fishing. A second more detailed model examined recreational fishing in the West Coast Bioregion of Western Australia. Similar results were obtained between the core and detailed models with an increased abundance of primary target species as a result of the closure and a decline in the alternative target species due to target switching. A strong ‘spike’ in fishing effort following the re-opening of the fishery may actually increase fishing effort as a result of a seasonal closure. Additional management strategies, including increased recreational fishing restrictions were investigated. The study identified the need for an understanding of target switching, effort spikes and the ‘value’ placed on primary versus alternative target species.