Rebuilding ecosystems, not sustainability, as the proper goal of fishery management

Abstract

We propose that rebuilding ecosystems, and not sustainability per se, should be the goal of fishery management. Sustainability is a deceptive goal because human harvesting of fish leads to a progressive simplification of ecosystems in favour of smaller, high-turnover, lower-trophic-level fish species that are adapted to withstand disturbance and habitat degradation. Present fisheries management seems unable to reverse this trend for several reasons. Because of this effect on the ecosystem, sustainable harvests are generally incapable of ever being defined using single species-population dynamics, yet almost all fishery science has been long engaged in trying to do this. Even if our science and management were capable of sustaining exploitation at a defined ecosystem structure, we argue that this is the wrong goal. Aquatic systems are likely capable of producing large harvests of high-production, low-trophic-level species, perhaps much in excess of current global fishery yields of around 100 million tonnes per year, yet such exploitation would shift their structure and nature in a way, and lead to products, that would be unacceptable to many. Primal systems, defined as those existing before humans used large-scale harvesting, are generally characterized by an abundance of large top-predator species. An approach to the primal abundance of such systems may have an increasingly higher economic value than present systems in an era where demand is outstripping supply. Therefore, we argue that management that moves aquatic systems in the direction of their primal states and abundance should be rewarded, and that this rebuilding and restoration of ecosystems should be the overarching goal of the new fisheries management.