Publication Abstract

Modelling fishing location choice within mixed fisheries: English North Sea beam trawlers in 2000 and 2001

T. Hutton, S. Mardle, S. Pascoe and R.A. Clark

Numerous studies have proposed methodology to model fishermen’s behaviour in order to predict the outcomes of the decision-making process on board a fishing vessel. Both short- and long-term processes (e.g. investment) impact on fleet dynamics. The structure of models that have been proposed depends on the nature of the fishery and the control variables (technical restrictions, quotas, effort control and/or closed areas). For example, within the context of multi-stock, multi-fleet fisheries (mixed fisheries), a skipper will allocate effort (as an input to the production process) in order to harvest a range of species. In addition, spatial complexity is normally excluded in models of behaviour. In this paper, two alternative spatial analyses are presented for the modelling of location choice: a simplified simulation model of individual vessels and a model based on random utility model (RUM) methodology. These models are applied to the English beam trawl fleet operating in the North Sea in 2000. The results from the RUM indicate that the number of trips, average trip length and average effort in each ICES rectangle are significant variables affecting location choice, in addition to a value weighted index of the catch rate for the previous year (i.e. 1999). The results validate the assumption (applied in the simulation model of fishing effort) that fishermen will make decisions as to their spatial location on expected catch rates (i.e. based on past activities). The simulation model is used to predict the distribution of the same fleet for one month during the temporary closure in the North Sea in 2001. It is shown that the predicted values for effort are well associated with the observed fishing patterns.

Reference:

T. Hutton, S. Mardle, S. Pascoe and R.A. Clark (2004) Modelling fishing location choice within mixed fisheries: English North Sea beam trawlers in 2000 and 2001. ICES Journal of Marine Science, 61(8): 1443-1452