Otolith science entering the 21st century

A review of 862 otolith-oriented papers published since the time of the 1998 Otolith Symposium in Bergen, Norway suggests that there has been a change in research emphasis compared to earlier years. Although close to 40% of the papers could be classifed as 'annual age and growth' studies, the remaining papers were roughly equally divided between studies of otolith microstructure, otolith chemistry and non-ageing applications. A more detailed breakdown of subject areas identified 15 diverse areas of specialisation, including age determination, larval fish ecology, population dynamics, species identification, tracer applications and environmental reconstructions. For each of the 15 subject areas, examples of representative studies published in the last 6 years were presented, with emphasis on the major developments and highlights. Among the challenges for the future awaiting resolution, the development of novel methods for validating the ages of deepsea fishes, the development of a physiologically-based otolith growth model, and the identification of the limits (if any) of ageing very old fish are among the most pressing.