Coral connectivity: Biophysical drivers, key knowledge gaps and emerging empirical advances

Chinenye Jane Ani , Camille Grimaldi, Anna Cresswell, Takuya Iwanaga, Barbara Robson 

Coral reefs are experiencing widespread decline from climate change and anthropogenic stressors, increasing the need to understand the processes that maintain and replenish coral populations. Connectivity—the exchange of individuals between coral populations—underpins population recovery, yet major uncertainties remain in larval biology and behaviour during dispersal and settlement. This review synthesises current knowledge of the physical and biological drivers of coral connectivity across hard and soft corals. We highlight well-studied processes such as spawning timing and identify key data gaps, including buoyancy, mortality, and competency during dispersal. High variability across taxa and locations complicates the identification of general connectivity patterns, particularly for processes that are difficult to observe in situ. Emerging techniques—including larval colouring, time series competency assays, acoustic enrichment, AI-based behavioural tracking and genetic barcoding—offer promising avenues to address these gaps. By summarising existing evidence and recent methodological advances, this review provides a foundation for improving empirical measurements and predictive models of coral connectivity to support conservation and restoration in dynamic oceans.