Oral Presentation Australian Society for Fish Biology Conference 2024

What's in a saw? An exploration of the chemical fingerprint of rostral teeth to gain insights into sawfish life history and spatial ecology  (111616)

Veronika N Biskis 1 2 , Patrick Reis-Santos 2 , Bonnie Holmes 2 , Bronwyn Gillanders 3 , Kathy A Townsend 4 , Barbara E Wueringer 1 5
  1. Sharks And Rays Australia, Cairns, QLD, Australia
  2. Science Technology and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
  3. School of Biological Sciences, The University of Adelaide, Adelaide
  4. Science Technology and Engineering, University of the Sunshine Coast, Hervey Bay, QLD, Australia
  5. School of Natural Sciences, Macquarie University, Wallumattagal Campus, NSW, Australia

Sawfishes are emblematic of many of the current challenges faced in marine conservation. Despite comprehensive protection measures across various levels in Australia, populations remain under threat from bycatch and illegal take for their rostra. While commonly available in collections, trophy rostra often have little associated location data, limiting their use in distribution analyses critical for effective conservation strategies. This study evaluates the use of trace elemental analysis via Induction Coupled Plasma Mass Spectrometry (ICPMS) of rostral teeth to identify capture location and origin estuary for narrow (Anoxypristis cuspidata), green (Pristis zijsron) and freshwater (Pristis pristis) sawfishes along the Queensland coast. We also analysed transects along the growth axis of adult teeth aiming to reconstruct life-histories movements, providing much needed insights on endangered elasmobranchs predominately represented in literature by juveniles. Preliminary spot results from 146 teeth across 16 estuaries show promise to pinpoint rostra origin at the regional level, reducing uncertainty by several hundred kilometres. This analysis not only bridges a knowledge gap in sawfish ecology, but also suggests that rostral teeth can serve as a non-lethal solution in obtaining life history data, continuing to build on the structures that can be used as tools in conservation and marine spatial planning.