This award will enable collaborative research between Dr. Richard Radtke of the University of Hawaii and Dr. Robert Gauldie of the Fisheries Research Center, Ministry of Agriculture and Fisheries, Wellington, New Zealand. They will conduct research aimed at extracting life history and physiological information on fish from structural and chemical analyses of fish otoliths. Yearly, daily and population rhythmic patterns in fish maintained under experimental conditions will be correlated with otolith macro- and micro-structure as observed by light and scanning electron microscopy. Chemical analyses of otolith carbonate for stable isotopic and elemental concentrations will be used to examine experimentally entrained changes in chemistry which in wild fish would constitute the history of an individual fish. Microprobe analyses will be used to interpret short-term changes in temperature. The combination of structural and chemical analyses of fish otoliths can potentially yield life history profiles for individual fish, together with information on the environmental history of the fish. Such information will increase our understanding of the processes underlying recruitment and growth rate and would make it possible to link growth and mortality rates to nutritional and environmental occurrences. The analytical equipment available in Dr. Gauldie's laboratory, together with the complementary skills of Drs. Gauldie and Radtke, make this collaborative effort particularly attractive.