Standard Presentation (15 mins) Australian Marine Sciences Association 2022

Continental-scale acoustic telemetry and network analysis reveal new insights into shark stock structure (#435)

Colin A Simpfendorfer 1 2 , Elodie J.I. Ledee 1
  1. College of Science and Engineering, James Cook University, Townsville, Qld, Australia
  2. Institute for Marine and Antarctic Studies , University of Tasmania, Hobart, Tas, Australia

Delineation of population structure is crucial for successfully manage of exploited species and to address conservation concerns for threatened species. Migration and associated movements are key mechanisms through which discrete populations mix and are thus important determinants of population structure. Detailed information on migration and movements is becoming more accessible through advances in telemetry and analysis methods; however, such information is not yet used systematically for investigating population structure. Here, we described how detections of acoustically tagged sharks across a continental-scale array of acoustic receivers were used to assess population structure in seven species and compared to findings from genetic and conventional tagging. Network analysis revealed previously unknown population connections in some species, and in others bolstered support for existing stock discrimination by identifying nodes and routes important for connectivity. Our study shows the power of continental-scale acoustic telemetry networks to detect movements among management jurisdictions. We highlight methodological issues that need to be considered in the design of acoustic telemetry studies for investigating stock structure and the interpretation of the resulting data. The advent of broad-scale acoustic telemetry networks across the globe provides new avenues to understand how movement informs population structure and can lead to improved management.