Movement Ecology of a Mobile Predatory Fish Reveals Limited Landscape-Scale Connectivity within a Temperate Estuary

The scales over which fishes move mediate habitat requirements, food-web dynamics, adaptability to environmental perturbations, and management strategies. We acoustically tagged and monitored the movement of 34 red-drum (Sciaenops ocellatus) within a temperate North Carolina estuary specifically to identify the dispersal rate of fish from a representative marsh complex, the spatial extent of their foraging arena (area covered per unit time) within the estuarine landscape, and the degree of connectivity between spatially distinct marsh complexes (0.5 – 2.0 km apart)?  We analyzed fish detection data through time relative to hydrophone distances from the release location and the spatial variance structure of those detections among all hydrophones.  Movement patterns could be readily characterized after only 1-2 weeks showing that fish typically remained within a 3-5km radius of the release location while occupying a weekly foraging arena of ~1 km². Overall, red-drum demonstrated significant preferences for a single marsh complex with little connectivity to similar habitat complexes despite distances of <1 km. These data highlight potential within-estuary spatial structure for mobile fishes, and should guide subsequent efforts to track energy flows in coastal food webs, predict the footprint of local habitat restoration benefits, and design survey regimes to quantify overall population demography.