This award supports the transportation and per diem costs of six U.S. participants in a U.S.-Australia Joint Workshop on Skeletal Microchemical Marine Fish Analysis, to be held in Hobart (Tasmania), Australia, March 2-6, 1992. The meeting takes place under the auspices of the U.S.-Australia Cooperative Science Program, and will bring together researchers who are using the relatively new technique of skeletal microanalysis to study marine fish populations. This approach, which involves x-ray spectrometric analysis of ossified structures (e.g. otoliths) in fish, offers an opportunity for greater understanding of the migration patterns of some commercially important fishes. The basis of this promise is the observation that trace element composition and isotope ratios in fish skeletal structures show differences depending on the environmental history of the fishes, such as the particular river system or other area where spawning occurred. The co-organizers of the seminar are Professor Robert C. Francis, Director of the Fisheries Research Institute, University of Washington, and Dr. Ronald Thresher, of the Australian CSIRO Division of Fisheries, Hobart, Tasmania. Australian participation is being supported by the Australian Department of Industry, Technology, and Commerce. There will also be a few attendees from other countries. The extent of dispersal of fishes from their spawning areas, as a result of passive movement of larvae and, later, the active migration of fish juveniles and adults, determines the geographic size of marine populations. Knowledge of the size, structure, and origins of these populations is of importance to ecologists, fisheries biologists, and those responsible for management of coastal habitats. Older procedures used to measure the movement of fishes, and thus the spatial scale of fish populations, have given ambiguous results. The relatively new technique of skeletal microanalysis offers important advantages, if it can be further de loped. Australian scientists are world leaders in this area, and most of the scientists using the new methodology are either in the U.S. or Australia. Different research groups are using different approaches, and difficulties still remain in the interpretation of results. The seminar will permit some of the most active practitioners of skeletal microanalysis to share their experimental details and results with their colleagues and with other scientists more grounded in the physical basis of the measurements. This is expected to lead to a greater understanding and utilization of the technique, and to a greater efficiency of effort in exploiting it in the future. The technology has potential for application in the U.S. Global Change Research Program (GLOBEC), an initiative to understand the marine animal population and ecosystem responses to global change. Based on the seminar, a summary document on applications of microchemical techniques to analysis of marine populations will be prepared.
