Simulation modelling of management issues related to hoki fishing in New Zealand

Abstract

The overall aim of the thesis was to apply the system dynamics simulation modelling approach to investigate factors which have an influence on the profitability and management of a vessel actively involved in hoki fishing in New Zealand. The general analytic perspective adopted was that of shareholders, potential investors, a strategic planning manager, or CEO. The focus of the model was not operational day to day management but rather identifying and analysing issues relevant to strategic planning over the economic life of the vessel. Factors affecting the economic returns or net present value of the vessel were investigated and compared. The study began with a review of wider fisheries management, policy and issues, then the focus narrowed to that of the hoki fishery in New Zealand. An annualised simulation model was developed based on a factory freezer vessel assumed to be used exclusively for hoki fishing. It was also assumed the fishing operation modelled did not impact on the market or the fish population modelled. The base case included a 'stock shock' that allowed management policies to reduce the effect of external instability to be examined. A range of sensitivity tests and policy experiments were conducted using the model. The study indicated the long term nature of the fishing operation required to achieve positive net present values, and hence the need for long term strategic planning. Five factors were found to affect the net present value by more than 100% with a (+/-) 10 percent change in each factor. The factors were price change, quota catch rate (whether the operation took all of its quota), the conversions factor (conversion of greenweight fish to final product), the exchange rate, and quota owned. The correct setting of Total Allowable Commercial Catch reduces the risk of fisheries collapse and of the deleterious effects of competition for catch under the Quota Management System. The model and some of the findings can be applied to other fisheries within New Zealand and overseas.