Mapping global shipless areas and conflict zones between shipping and large marine vertebrates

Abstract

The growth of global maritime traffic poses increasing threats to marine biodiversity, including vessel collisions, behavioural disturbances, and pollution. Protecting areas with minimal shipping activity and identifying high-risk conflict zones between biodiversity and vessel traffic is crucial for conservation and mitigation efforts. However, a comprehensive assessment of these threats has yet to be conducted. We present a global analysis of shipless areas and examine the overlap between shipping density and the distribution of marine taxa known to be impacted by vessel activity—namely, cetaceans, sea turtles, pinnipeds, and seabirds. We identify regions where high biodiversity coincides with either low or intense vessel activity, designating them as Priority Preservation Areas and Priority Mitigation Areas, corresponding to low- and high-conflict zones. We also assess the extent to which Marine Protected Areas, Exclusive Economic Zones, and High Seas encompass these zones. Our results show that MPAs currently cover 12.1 % of shipless areas, 15.2 % of PPAs, and 16.2 % of PMAs, while no-take MPAs cover 6.8 % of shipless areas, 9.5 % of PPAs, and 5.6 % of PMAs. Our findings reveal that shipless areas are mainly restricted to polar and remote oceanic regions. PPAs are mostly located at high southern latitudes, while PMAs are concentrated along coasts, particularly in the mid-Pacific, southern Indian Ocean, and South Atlantic. We underscore the need to preserve low-conflict zones and implement targeted mitigation strategies—such as traffic rerouting and speed reductions—in high-conflict areas. Our framework supports global marine conservation goals, including the 30 × 30 biodiversity target.