Methods for Evaluating the Impacts of Fisheries on North Atlantic Ecosystems
Small Versus Large-scale Fisheries: A Multi-species, Multi-fleet Model For Evaluating Their Interactions And Potential Benefits
L. M. Ruttan*, F. C. Gayanilo Jr., U. R. Sumaila and D. Pauly
Fisheries Centre, University of British Columbia
*Present address: Workshop in Political Theory and Policy Analysis, Indiana UniversityAbstract
In this paper, we present a method for evaluating the economic losses and biological impacts of a lack of co-ordination of effort on the part of small versus large-scale fisheries. We illustrate our method using fisheries of the Gulf of Maine and the George’s Bank (USA). There are several novel methodological components of this work. First, we use an approach for defining which fisheries are small and which are large on a scale that is specific to political units since gear that is large-scale in one country may be categorized as small-scale in another. Second, we present a multi-species, multi-fleet, yield-per-recruit model that incorporates gear selection curves for each gear type. This permits an evaluation of the economic benefits of trade-offs in effort between the two small and large-scale fleets. Optimal combinations of effort by the two fleets are identified by subtracting costs of fishing effort from the gross value calculated by the model. Third, we estimate the value of foregone profits by comparing the rents produced at such an optimum with those produced by the current fishery. Finally, we identify a Nash bargaining solution that would be obtained if both sectors chose to cooperate by coordinating their levels of effort.