SS1.02 Geochemical Tracers in Calcified Structures: Implications for Fisheries Research
Date: Tuesday, June 11, 2002
Time: 4:15:00 PM
Location: Carson A
 
PattersonHM, School of Marine Biology, James Cook University, Townsville QLD, Australia, Heather.Patterson@jcu.edu.au
Kingsford, M, J, School of Marine Biology, James Cook University, Townsville QLD, Australia, Michael.Kingsford@jcu.edu.au
McCulloch, M, T, Research School of Earth Sciences, The Australian National University, Canberra ACT, Australia, Malcom.McCulloch@anu.edu.au
 
ELEMENTAL SIGNATURES IN PRESETTLEMENT CORAL REEF FISH OTOLITHS AT HIGH SPATIAL RESOLUTION USING LA-ICPMS
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The paradigm has long been that coral reefs are open systems, where recruits at a location may originate from multiple source reefs. Recent evidence, however, suggests that populations are also seeded by larvae from natal reefs. Otolith chemistry has the potential to identify the spawning/hatching location of recruits if each reef has a unique signature; otolith chemistry is derived primarily from water chemistry although this relationship is complex and poorly understood. In a three-year manipulative study at One Tree Island on the southern Great Barrier Reef we experimentally determined that presettlement Pomacentrus coelestis exposed to different water masses produced different elemental signatures in the otoliths. Analysis using LA-ICPMS at very high spatial resolution detected changes in Ba/Ca that potentially reflect the depletion of Ba in the water column due to algal blooms. It was also possible to document daily fluctuations in the deposition of elements into the aragonite matrix. Otolith chemistry, therefore, is a promising method to address the broader issue of connectivity among coral reefs and events happening through early life.