Seascape heterogeneity and predictability drive movement strategy selection in estuarine predators

Animal movement strategies, or suites of correlated traits reflecting how individuals respond to their environment, are often shaped by spatiotemporal heterogeneity and predictability in physicochemical conditions, resources or risk. While movement strategies have been well studied in terrestrial animals using high-resolution satellite telemetry, our understanding of how seascape heterogeneity influences movement strategies in aquatic systems remains limited due to technological constraints. We used a non-gridded passive acoustic telemetry array to identify and classify movement strategies of Common Snook (Centropomus undecimalis) and Atlantic Tarpon (Megalops atlanticus) within two estuarine systems in Everglades National Park, Florida. We then evaluated how seasonal heterogeneity and environmental predictability influenced movement strategy selection. Using a suite of movement metrics, we identified three statistically distinct movement strategies that varied in movement frequency, home range size and site fidelity. Fish in more homogeneous environments tended to adopt strategies involving frequent movements, larger home ranges and shorter stays in a given location. In contrast, increased seascape heterogeneity was associated with movement strategies characterized by less frequent movements, smaller home ranges and longer residence times. We also found species-level differences in strategy use, with the predictability of dissolved oxygen, salinity and turbidity emerging as key environmental drivers of movement strategy selection. These results demonstrate that seascape heterogeneity and predictability strongly influence the emergence and selection of movement strategies in estuarine predators. Our findings provide a novel approach for identifying movement strategies in aquatic systems using passive acoustic telemetry and highlight the broader importance of seascape complexity in shaping animal behaviour and predicting responses to environmental change.