Evaluation of habitat quality for juvenile fishes in contrasting mid-Atlantic seascapes

Estuarine and coastal areas facilitate the growth and survival of juvenile fishes and are critical for recruitment and fisheries production. Identification of high-quality habitats for economically important juvenile fishes can provide guidance for protecting these habitats and ensuring long-term fishery stability. We used a seascape approach to identify essential habitats for juvenile summer flounder Paralichthys dentatus and spot Leiostomus xanthurus in the Piankatank River, a sub-estuary of Chesapeake Bay, USA, and an Atlantic coastal lagoon on the Eastern Shore of Virginia, USA. Our approach characterized marsh, oyster, seagrass, and unstructured soft-bottom habitat features at multiple spatial scales and evaluated relationships between habitat features and fish relative abundance, body condition, and growth. Juvenile summer flounder and spot exhibited an affinity for marsh habitats. Mid-Atlantic marshes are vulnerable to multiple threats including sea-level rise, and continued loss may negatively affect juvenile fish production. Habitat quality (as indicated by body condition and growth) for both species was similar across study areas despite notable differences in seascape composition. Seascape characteristics had equivocal influences on relative abundance, body condition, and growth of both species, which may suggest use of multiple habitat types or that our study areas were functionally similar in terms of habitat quality. Comparison of juvenile fish habitat quality in seascapes with wider ranges of ‘good’ and ‘poor’ seascape characteristics could elucidate these relationships. Evaluation of fish-habitat relationships would also benefit from consideration of species-specific habitat thresholds and fish movements.