Exploring the Relationship Between Scale and Otolith Geochemistry in Striped Bass (Morone saxatilis).

Alper, Brian¹, Lisa Kerr², Zachary T. Whitener³, Roger A. Rulifson⁴, Nathan R. Miller⁵, Alicia Cruz-Uribe², John A. Mohan¹, ¹University of New England, Biddeford, ME, ²University of Maine, Orono, ME, ³Gulf of Maine Research Institute, Portland, ME, ⁴East Carolina University, Greenville, NC, ⁵University of Texas at Austin, Austin, TX

Striped bass (Morone saxatilis) are an anadromous species that support commercial and recreational fisheries along the eastern coast of North America. Due to population declines, the species is recently classified as “overfished”, with overfishing occurring. Since striped bass migrate annually, there is often spatial overlap between populations with different natal origins in coastal waters. Stock identification methods that allow for distinguishing between populations can help determine effective management strategies to maintain population diversity. Otoliths have become a standard tool in stock identification because they accrete throughout the lifetime of the fish and incorporate elements from surrounding water that reflect gradients in water chemistry. Otolith sampling is lethal which can present challenges for species at low abundance or with harvest restrictions. Fish scales might offer a non-lethal chemical tracer of environmental history, if their elemental composition proxy those in otoliths during concurrent growth. Additionally, scale sampling could involve recreational catch-and-release anglers. In this study, we compared the trace elements of striped bass scales and otoliths (n=17) targeting the first year of life to determine if scales could be used as a reliable proxy of juvenile habitat use. We find that both strontium and barium display significant positive correlations between scales and otoliths, highlighting the potential of scales have as a non-lethal alternative to otoliths.