Multicriteria analysis of log-set strata closures to reduce the mexican tuna fishery incidental catch

Abstract

 Concordance analysis, a multicriteria technique, was used as a decision-making tool. To exemplify the use of this tool, five closure options were evaluated to decrease incidental catch of mahi-mahi or dolphin-fish, Coryphaena spp., by the Mexican eastern Pacific tuna fishery using log-sets. The options consist of combinations of spatial and temporal strata subject to closures, and were evaluated using four eco-biologic and techno-economic criteria. A set of solutions was generated using 286 parametric representations of the weights-vector due to the difficulty of knowing the real preferences of decision-makers. The option with the highest probability of being chosen (almost 0.6) closes three large areas throughout the year for log-sets. This option would reduce mahi-mahi incidental catch in just over 85%, and almost 92% that of other species. However, this option represents the highest cost in terms of lost gross revenues and leaves only eight strata open for the log-set fishery.