River Herring Nursery Habitat Use in Albemarle Sound, NC: Inferred Using Otolith Microchemistry

River herring stocks in North Carolina have been declining for more than 25 years.  Important river herring nursery habitat must be identified to ensure that harvest moratoriums and other recovery efforts are successful. Not only is it important to identify habitat use of juvenile fish, but it is essential to identify the nursery habitats used by mature adult fish, which represent successful recruits.  We used otolith microchemistry to infer nursery habitat use of adult and juvenile river herring in the Albemarle Sound, North Carolina.  Water samples and otolith elemental composition were used to identify unique signatures for individual watersheds. Inductively coupled plasma mass spectrometry was used to analyze adult and juvenile otoliths. We found individual watersheds and areas within individual watersheds to have distinct elemental signatures.  Based on otolith elemental composition, adult and juvenile river herring could be accurately assigned to their watershed of capture.  Comparing elemental concentrations in juvenile otoliths with the elemental concentrations of water samples allowed for determination of upstream and downstream habitat use.  In addition, otolith elemental composition could be used to trace movements of juvenile river herring between watersheds.  Based on movement and condition indices it appears some tributaries of the Albemarle Sound may provide better habitat for river herring than others.