New advances and challenges from the 7th International Otolith Symposium

Abstract

Fish otoliths are calcareous structures that have been widely used for decades to determine in age and growth determination as basic information that is paramount for the management of fish stocks globally. The rapid growth in in technological advances in the last decades, such as the analysis of the chemical composition within the otolith structure and of the otolith morphometry, has meant that otoliths can now be used more widely to inform our knowledge of the life history of fishes, both past and present, and of fish population changes. This special issue of Fisheries Research contains the latest contributions from the 7th International Otolith Symposium (IOS 2023), held in October 2023, in Viña del Mar, Chile. A total of 205 delegates from 39 countries participated in the IOS 2023, with scientific presentations covering numerous topics related to otolith research. These included: otolith formation and composition, evolutionary biology of fish, life history studies, and aquatic ecosystem ecology. Studies using chemical composition of otoliths were seen to be providing valuable insights into habitat use, demographic patterns, trophic ecology, palaeo-reconstruction of ichthyofauna, physiological processes, and fish migration pathways. In addition, case studies using otolith-based biochronologies, demonstrated the usefulness and application of this technique to help reveal biological patterns at annual to centennial time scales to potentially provide long-term ecological insights into the impacts of climate change on aquatic ecosystems. The symposium scope was enhanced by four disciplinary workshops and six keynote conferencesspeakers, all of which highlighted the importance of continued research in otolith science, and the need for interdisciplinary approaches combining otolith-based records with other fields of study.