Habitat use of juvenile striped bass Morone saxatilis (Actinopterygii: Moronidae) in rivers spanning a salinity gradient across a shallow wind-driven estuary

摘要

Transient and resident habitat utilization patterns were described for juvenile striped bass Morone saxatilis in Albemarle Sound, North Carolina, using otolith elemental chronologies. As fish grew and migrated across the sound and into river habitats, influences from the ambient environment became dominant on elemental patterns. Otolith Ba:Ca was the most reliable element to discern fish movement across the salinity gradients in Albemarle Sound. Resident fish displayed faster growth (mean +/- standard deviation: 1.3 +/- 0.23 mm/d) than transients (1.1 +/- 0.22 mm/d), indicating that residents may have located high quality habitats and remained there, while transient fish expended energy searching for more optimal habitat. Faster growth rates (1.31 +/- 0.22 mm/d) and only resident fish were found in the Pasquotank River, which may be an important nursery habitat for juvenile striped bass. Slow growth (1.19 +/- 0.26 mm/d), and more transients (53 %) were found in traditional nursery areas in Batchelor Bay at the mouth of the Roanoke River, indicating that these habitats may not be supporting high growth, causing fish to move out of these areas. This study discerns fine scale movements of juvenile striped bass and identified resident and transient contingents by combining otolith microchemistry with daily increment analysis to investigate the consequences of migratory behavior on fish growth.