Using Biogeochemical Markers to Track Migratory Histories of Diadromous Fishes

The development of isotopic and trace elemental micro-analytic methods revolutionized ecology and fisheries science.  Although both realms enable studies of energy flow and food web organization, they also provide “natural tags,” incorporated into hard and soft tissues, and can be used to follow migrations.  As a result, we have gained many new insights into the complexity and diversity of migratory behaviors, and are beginning to understand movements in “the black box” of marine phases of diadromous fishes.  We provide a brief history of the field, provide examples, and look forward at future developments.