Quantifying the squeezing or stretching of fisheries as they adapt to displacement by marine reserves

Abstract

The designation of no-take marine reserves involves social and economic concerns due to the resulting displacement of fishing effort, when fishing rights are removed from those who traditionally fished within an area. Displacement can influence the functioning of the fishery and success of the reserve yet levels of displacement are seldom quantified after reserve implementation, and very rarely before that. Here we present a simple analytical framework based on set theory to facilitate reserve placement. Implementation of the framework requires maps of fishing grounds, effort, or catch per unit effort for at least two years. The framework quantifies the level of conflict that a reserve designation might cause with the fishing sector due to displacement and the opportunities to offset it through spatial mobility, or the ability of fishers to fish elsewhere. We also show how the outputs of the framework can be used to identify targeted management interventions for each fishery. The method is showcased in Honduras, where the largest marine protected area in Central America is being placed and spatial effort data are available for six fisheries and three years. In Honduras, the proposed closure will have a greater impact on shrimp and lobster SCUBA fisheries, which have little room to accommodate the displacement within existing fishing grounds, and will be forced to stretch and use new fishing grounds, which are available, but of unknown quality. Adaptation of these stakeholders will likely require compensatory measures to offset costly exploratory fishing and/or travel to fishing grounds further away from port. This article is protected by copyright. All rights reserved.