Fishing Tactics in a Two-Species Fisheries Model: The Bioeconomics of Bycatch and Discarding

Abstract

The selections for fishing location largely determine the species mix and value of a fisher's catch. Because of travel costs, these choices also determine the profitability of a fishing trip. This paper develops a simple theoretical model for the selection of fishing locations by a fisher faced with two co-occurring species whose densities vary with distance from port. For each species there can be different catchability coefficients, handling times, and prices. The duration of each fishing trip is assumed fixed. The model is used to determine the profit-maximizing fishing tactics (the fishing locations and time spent at each location) and to explore the conditions that generate deliberate bycatch and discarding when one of the species cannot be sold because it is unmarketable or because of trip limits.