Use of micro‐PIXE to investigate otolith Sr distributions of the anadromous striped bass, Morone saxatilis

Abstract Migration patterns of anadromous Atlantic coast striped bass, Morone saxatilis , have been determined primarily through mark and recapture studies. These studies provide little information about the duration, seasonality and frequency of estuarine and ocean migratory phases of migration, nor have they identified the age at which striped bass first exhibit anadromy. In order to investigate how otolith Sr distributions can contribute to these aspects of fish life histories, otoliths from striped bass of the Roanoke‐Albemarle Sound, North Carolina population were analyzed using a scanning proton microprobe (micro‐PIXE). The results suggest that micro‐PIXE can provide detailed information about migration patterns for this population. Differences in striped bass migration were observed. Two fish exhibited emigration to ocean habitats at 2 years of age. Interestingly, the two movement patterns observed, one resident and one migratory, were related to the three major genotypes (mtDNA) of this population, suggesting that timing and appearance of anadromy might be related to lineage for this species. Additional sampling will be necessary in order to confirm this hypothesis. Copyright © 2005 John Wiley & Sons, Ltd.