Dispersal corridors enhance modelled near-bed larval connectivity across deep-sea protected area networks

The Clarion–Clipperton Zone (CCZ) is the focal region for imminent deep-sea nodule mining, with over 1.1 million square kilometres already under exploration licence. Although the International Seabed Authority has designated Areas of Particular Environmental Interest (APEIs) to protect regional biodiversity from mining impacts, there has been no formal assessment of whether this network functions as a coherent connected system. Here we use Lagrangian dispersal modelling and network analysis to provide a region-wide assessment of modelled larval connectivity across the CCZ and show that simulated larval exchange among APEIs is extremely limited. Under physically driven near-bed dispersal and reasonable pelagic larval dispersal times of 19–69 days, fewer than 0.02% of particles reach another APEI, with inter-APEI gaps exceeding modelled dispersal capacity. CCZ-wide dispersal is structured into four semi-isolated connectivity communities, and under mining disturbance when self-supply is removed from Areas of Mining Interest, unprotected non-mining areas emerge as the dominant modelled source of replenishment. Strategic corridor additions increase inter-APEI dispersal 406-fold and nearly doubles modelled replenishment from protected areas under disturbance, providing a reproducible, connectivity-informed evidence base for conservation design ahead of commercial mining.