Optimizing the Methodological Design in Fish Stock Delineation from Otolith Chemistry: Review of Spatio-Temporal Analysis Scales

Abstract The otolith chemistry is one of the most commonly used tools to elucidate the structure of fish stocks. The correct application of this methodology depends on the fulfillment of several assumptions. One of the most relevant assumptions is that the otoliths and water chemistries vary at appropriate spatio-temporal scale in relation to the hypotheses being addressed. Due to the increase in the number of publications where this assumption is not properly considered, it is essential to discuss and order different concepts to contribute to the correct interpretation of the information provided by the otolith chemistry applied to the delimitation of stocks. Herein, the opportunity for dispersal concepts in otolith chemistry-based stock discrimination methods is discussed integrating the space-time scales, and biogeographic foundations. Additionally, a graphic guide was developed to facilitate hypothesis testing and their respective interpretations. This article encourages further use and attention on age and growth data, dispersal ability and life history, but further integration of the issue of biology versus management, as well as how the integration of other approaches may assist, is recommended, as most likely there will be no single approach to resolve stock structure.