Tracking shark spatial mobility patterns using 14C measurements on vertebrae growth bands
Dr Yota Harada1, Dr Johan Gustafson2, Dr Quan Hua3, Dr Philip M. Riekenberg4, Dr Axel Steinhof5, Dr Ricardo Fernandes6,7,8
1 Biogeochemistry Research Center, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan, 22. Coastal and Marine Research Centre, Southport , Australia, 33. Australian Nuclear Science and Technology Organization , Kirrawee , Australia, 44. NIOZ, Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Den Hoorn, Netherlands, 55. Max-Planck Institute for Biogeochemistry, Jena, Germany, 66. Max Planck Institute for the Science of Human History, Jena, Germany, 7University of Oxford, Oxford, United Kingdom, 8Masaryk University, Brno, Germay
Information on shark spatial mobility patterns is crucial to understand their feeding ecology and to identify prospective marine protected areas essential for their conservation. In this respect, radiocarbon can make a useful contribution by exploring spatial variations in marine radiocarbon reservoir effects. Here, we report data for seven sharks (1× scalloped hammer head, 1× tiger shark, 2× great hammer head, 3× great white shark) found dead off the Brisbane coastal region in Australia between 2016 and 2019. To examine temporal variations in dwelling areas and feeding habits, separate growth band samples were taken from a vertebra of each specimen for AMS 14C measurements, for carbon and nitrogen stable isotope analyses of bulk collagen, and nitrogen stable isotope analysis of single amino acids. Here we show considerable variability in 14C values among the different specimens and across time for each specimen which is indicative of individual spatial mobility patterns. We will discuss the use of novel Bayesian approaches to map temporal dwelling areas for each specimen by comparing shark vertebrae 14C results with the spatial distribution of surface marine radiocarbon levels effects . This has the potential of offering a new research tool for conservation purposes.
Biographies to come