Otolith chemistry of juvenile snapper Pagrus auratus in Victorian waters: natural chemical tags and their temporal variation

Abstract

Determining contributions of juveniles from different areas to adult populations is difficult using traditional methods such as manual tagging and recapture. Environmental variation can, however, produce natural chemical tags in the otoliths of juvenile fish. Spatial variation in the otolith chemistry (Ba, Sr, Mn) of age 0+ snapper collected from inlets along the coast of Victoria, southeastern Australia, enabled characterisation of otolith chemical tags for specific areas. In particular, a tag based largely on high Ba levels was specific to snapper from the largest juvenile area and most important fishery, Port Phillip Bay. This tag enabled accurate discrimination between snapper from this ..