Risk sensitivity and the behaviour of fishing vessels

Risk sensitivity is an important component of fisher behaviour, yet its impact on fisher decision-making and utility is poorly understood. Here, we incorporate various forms of risk in a model of location choice by fishing vessels targeting broadbill swordfish, Xiphias gladius, and evaluate the importance of risk sensitivity for predicting location, perceived utility and profit over a fishing season. We consider short-term, or trip-level, risk as natural, social or endogenous. Longer-term, or seasonal, risk includes accumulated profit as a state variable. When considering only short-term risk, endogenous and social risks are predicted to have the largest impact on profit, while natural risk also is predicted to impact on location choice. When longer-term (seasonal) risk was considered, the impacts of short-term (trip-level) risks on profit were reduced. Model results were somewhat sensitive to assumed input parameters. The model allows users to quantify the extent of risk interaction and the relative sensitivity of perceived utility, location choice and profit. By providing a utility function capturing the fisher decision-making process, the model provides a platform for the consideration of simultaneous forms of risk under different circumstances.