Where are the chokepoints? Exposing the global straits’connectivity pattern using the port-strait bimodal network

Maritime straits are pivotal nodes in the global shipping network, with their significance shaped by both intrinsic characteristics and connectivity to onshore ports. While prior studies emphasize traffic volume, the structural connectivity of straits remains underexplored. This study constructs a bimodal maritime network linking major ports and straits, integrating traffic data with network analysis to assess strait importance. The study reveals that from 2012 to 2022, core straits, notably in the Indo-Pacific, Mediterranean, and eastern North Atlantic regions, show a clustering trend in connection strength. In terms of connectivity breadth, the number of core straits with the highest port connections has decreased, with primary links between ports and straits concentrated in the Indo-Pacific straits and ports across Asia and Europe. Regarding connectivity precision, from 2012 to 2019, the centrality of straits in the core network has generally increased, with a notable dip in 2020 followed by a rebound in 2022. Assessing chokepoints based on connectivity strength, breadth, and precision, global chokepoints include the Malacca, Taiwan, and Korean Straits, while regionally impactful ones comprise the Gibraltar Strait, Tunis Strait, Palk Strait, Qiongzhou Strait, and Dardanelles Strait, alongside nine others with local influence.