The blue paradox: Preemptive overfishing in marine protected areas

About

Can the announcement of an impending no-take marine reserve trigger an unintended race-to-fish? While no-take marine reserves are designed to catalyze environmental improvements, the announcement of a marine reserve —which can precede its actual implementation and enforcement by a year or more—may inadvertently trigger adverse environmental effects. With the knowledge that they will soon lose access to their fishing grounds, fishers might increase their fishing activity inside the proposed marine reserve. Such preemptive behavior has the potential to undermine the anticipated benefits of the marine reserves by temporarily depleting populations below where they would have been without the announcement. As a result, it may be years or decades before the new marine reserve recovers back to its pre-announcement status. 

We tested this theory, using the Phoenix Islands Protected Area (PIPA) in Kiribati as a case study. 

Approach

We leveraged Global Fishing Watch’s vessel tracking dataset to look at fishing effort within PIPA, one of the world’s largest and most celebrated marine reserves, and a control region composed of two other island groups in Kiribati. We observed the fishing effort both before and after a total ban of commercial fishing in PIPA was implemented on January 1, 2015. 

Key Findings

Within PIPA and relative to the control region, we observed a dramatic spike in fishing effort in the period leading up to the ban, as fishers preemptively harvested resources while they still could. This extra fishing — equivalent to 1.5 years of avoided fishing during the ban — placed PIPA in a relatively impoverished state when the policy was eventually enforced. We call this phenomenon the “blue paradox.” Extrapolating this behavior globally, we estimate that if other marine reserve announcements were to trigger similar preemptive fishing behaviour, it could temporarily increase the share of global over-extracted fisheries from 65% to 72%. To reduce this blue paradox effect, we recommend reducing the policy design period and the duration of time between marine reserve announcement and enforcement.

Partners

This project was a collaboration with Dr. Grant McDermott at the University of Oregon, completed with support from Global Fishing Watch.