Fish Otoliths as indicators: results of the V International Otolith Symposium (IOS2014)

The implementation of ecosystem-based approaches to marine management points to several shared objectives between conservation and fisheries management that require: better knowledge of the life history of the exploited resources; to elucidate the information encoded into the calcified tissues (otoliths, scales, bones, shells and corals) of marine and freshwater organisms; to support knowledge-based sustainable ocean management and use. IOS2014 was the 5th in a series of independent symposia which have been convened, beginning in 1993, to encourage the exchange of information and expertise and promote the development of new techniques and applications for otolith-based analysis in ecology, management, and conservation. The aim of the Symposium was to explore the use of calcified tissues as tools to support management and define indicators at environmental, community, population and individual levels. Despite the economic difficulties worldwide, a total of 329 registrants from 45 countries attended the Symposium. The symposium was organized around four themes: Environmental indicators, Community indicators, Population indicators, and Individual indicators. One day was devoted to workshops; on Otolith Shape Analysis and on Age Validation. The traditional approach of using calcified tissues to determine fish age and therefore to determine the fish population structure has been augmented by new applications to address questions of population connectivity, migrations, and trophic ecology. These tools have become increasingly important as we transition to spatially explicit and ecosystem-level management tools. They are now extended to applications related to spatial use (essential habitats) and to the use of otoliths as a record of past and present environmental conditions. Otoliths are valuable as individual bio-recorders, and – as demonstrated in the variety of presentations at the symposium – also as indicators for higher levels of organisation. The increased appreciation for otolith archives was also apparent; taking advantage of the extended otolith sampling for stock assessment and providing ample collections from different species, as well as from the fossil records.