UK Fleet Restructuring Model - Mathematical Aspects

Summary

Whilst this report deals exclusively with technical aspects of the current SFIA approach to mathematical modelling of the UK Fishing Fleet, it is important to be aware of some background and justification. Early attempts at fleet modelling by the White Fish Authority led to the formation of the Interdepartmental Fisheries Modelling Group, with members from WFA. MAFF and DAFS. Their objectives were to predict the ‘best’ UK fleet composition required to take allowable catches foreseen under various scenarios of EEC policy and fishery resource conservation. This was first tackled using a linear programming (LP) model designed to allocate the fleet in some optimal way, such as to maximise overall profit whilst satisfying strict physical constraints (species quotas, vessel number, etc). Although LP solutions are often acceptable, the method has its drawbacks in applications such as this one. It invariably produces violent changes in fleet allocation in pursuit of some marginal benefit; it is extremely selective in deciding which parts of the fleet to use, ignoring the rest altogether; finally, it always gives solutions on the very limits of what is feasible. Nevertheless, the LP approach did bring benefits, such as amalgamating detailed data from England, Wales and Scotland. This report has been produced from a scanned original and may therefore contain some formatting and other inaccuracies. In cases where this affects the technical content, a paper copy of the original report can still be obtained from Seafish

Publication Reference No.

SR192

Publication date

01 November 1982