Predatory fishes are key drivers of coral reef community structure and ecosystem function, yet their distribution across complex, submerged seascapes remains understudied. Submerged reef features such as pinnacles and seamounts represent ubiquitous yet understudied habitats in tropical oceans. Initial research by our group in Papua New Guinea, demonstrates that submerged pinnacle reefs may act as "ecological magnets," supporting 2 to 4 times higher abundance, biomass, and diversity of predatory fishes than adjacent emergent nearshore and offshore reefs. These hotspots harboured distinct species assemblages, driven by resident reef predators (e.g., serranids and lutjanids) alongside schooling pelagics (e.g., carangids and sphyraenids) likely capitalising on local hydrodynamic currents and pelagic trophic subsidies.
To investigate this phenomenon across broader seascapes, we expanded our research to the seamount reefs of the Coral Sea. By integrating fine-scale benthic structural complexity derived from ROV video transects with broad-scale biogeographic drivers (distance from the Coral Triangle, proximity to the Great Barrier Reef, reef area, and reef isolation), we modeled predator distributions across spatial scales and mesophotic depth gradients. Findings indicate that while local benthic complexity may influence predator abundance, macro-scale biogeographic drivers and isolation shape community structure and functional trait composition—differentiating schooling pelagic predators from resident ambush species. Synthesising local pinnacle "magnet" dynamics with seascape-scale biogeography highlights the critical role of submerged reefs in sustaining predator biomass and functional diversity, providing vital insights for regional marine spatial planning and tropical reef conservation.