Spatial protection measures have become ubiquitous in fisheries management and marine conservation. Implemented for diverse objectives from stock rebuilding to biodiversity protection and ecosystem management, spatial measures range from temporary fisheries closures to marine protected areas (MPAs) with varying levels of protection. While ecological and economic benefits from spatial protection have been demonstrated for many reef and demersal species, they still remain debated and understudied for highly migratory fishes, such as tunas, billfishes, and pelagic sharks.
This article summarizes the spatial extent of fisheries closures implemented by the tuna Regional Fisheries Management Organizations (RFMOs), as well as MPAs worldwide, which together cover ~15% of global ocean area. The results from modelling and tagging studies, as well as fisheries-dependent research are also synthesized to provide an overview of the efficacy and benefits of present spatial protection measures for large pelagic fishes and their associated fisheries.
The authors conclude that: 1. many species with known migration routes, aggregating behaviour, and philopatry can benefit from spatial protection; but 2. spatial protection alone is insufficient and should be integrated with effective fisheries management to protect and rebuild stocks of highly migratory species.
The authors suggest tailoring spatial protection to the biology of large pelagic fishes, including improved protection for aggregation sites and migration corridors. It is highlighted that these features currently appear to be an important, yet overlooked, opportunity to safeguard depleted and recovering stocks and protect pelagic biodiversity.
Boerder et al. (2019) Not all who wander are lost: Improving spatial protection for large pelagic fishes. Marine Policy 105:80-90.