Marine Dispersal Scales Are Congruent over Evolutionary and Ecological Time

The degree to which offspring remain near their parents or disperse widely is critical for understanding population dynamics, evolution, and biogeography, and for designing conservation actions. In the ocean, most estimates suggesting short-distance dispersal are based on direct ecological observations of dispersing individuals, while indirect evolutionary estimates often suggest substantially greater homogeneity among populations. Reconciling these two approaches and their seemingly competing perspectives on dispersal has been a major challenge. Here we show for the first time that evolutionary and ecological measures of larval dispersal can closely agree by using both to estimate the distribution of dispersal distances. In orange clownfish (Amphiprion percula) populations in Kimbe Bay, Papua New Guinea, we found that evolutionary dispersal kernels were 17 km (95% confidence interval: 12–24 km) wide, while an exhaustive set of direct larval dispersal observations suggested kernel widths of 27 km (19–36 km) or 19 km (15–27 km) across two years. The similarity between these two approaches suggests that ecological and evolutionary dispersal kernels can be equivalent, and that the apparent disagreement between direct and indirect measurements can be overcome. Our results suggest that carefully applied evolutionary methods, which are often less expensive, can be broadly relevant for understanding ecological dispersal across the tree of life. •Evolutionary estimates of dispersal matched direct observations in clownfish•Dispersal kernels across short and long timescales were highly similar•Our results suggest that evolutionary estimates of dispersal can be applied broadly Population genetic patterns often suggest widespread dispersal in the ocean, despite direct observations of local larval retention. Here, Pinsky et al. reconcile the two approaches and demonstrate that both estimate the same dispersal kernel. This suggests that evolutionary approaches could be used to study dispersal across many more species.