Age in Years from Otoliths of Adult Tropical Fish

Abstract

Otoliths of fish are hard, calcified internal structures that assist in orientation and sound perception (Popper et al. 2005, Green et al., Chapter 1, this volume). As otoliths grow inside each fish’s head they record an extraordinary amount of information about the life of that fish and the environments that it experiences (Begg et al. 2005). The challenge to scientists is to retrospectively access this information, to interpret it accurately in terms of the biology and life history of the fish, and to use the data to appropriately understand and manage the natural resources of the fish population and the broader aquatic ecosystem. The greatest application of otoliths to date has been in providing information on the age and growth of fish in years, which has ultimately been used in the management of associated fisheries (Campana & Thorrold 2001, Campana 2005). Prior to the 1980s, and stretching back to the late 19th Century, most such ageing work was done in the temperate regions of the world and contributed to managing the enormous fisheries in the oceans of these regions (Beamish 1992, Beamish & McFarlane 1995).