Speed Presentation 2024 Australian Marine Sciences Association Annual Meeting combined with NZMSS

Mesoscale ocean dynamics predict fisheries interaction risk for an endangered seabird (#360)

Ho Fung Wong 1 , David Schoeman 1 , Luke Halpin , Lily Bentley 2 , Samhita Bose 3 , Igor Debski 3 , Johannes Fischer 3 , Graeme Elliott 3 , Kath Walker 3 , Peter I Miller 4 , Kylie L Scales 1
  1. University of Sunshine Coast, Brisbane, QLD, Australia
  2. University of Queensland, Brisbane, Queensland, Australia
  3. Department of Conservation, New Zealand Government, Wellington, New Zealand
  4. Plymouth Marine Laboratory, Plymouth, UK

Fisheries bycatch has been widely studied to identify risk hotspots and inform management. However, uneven attention has been placed on seabird life-history stages while few studies have incorporated real-time oceanographic signals. Here, we modelled hotspots of interaction risk using tracking data from all life-history stages of 192 Antipodean albatrosses between 2019 and 2022, overlaid with Automatic Identification System (AIS) vessel-tracking data. We characterised bio-physical conditions underlying interaction risk hotspots on monthly scale and multi-year seasonal climatologies by building Generalised Additive Models (GAMs) with mesoscale turbulence and other sub-mesoscale signals to investigate the underlying pattern of (i) seasonal presence of overlap and; (ii) monthly intensity of interaction risk. Overall, the interaction risk of albatross was significantly higher during the austral Autumn and Winter (May–August) and in juveniles. Locations with elevated interaction risk varied between the life stages. Frontal frequency was the best predictor climatologically. The best predictor for the monthly intensity was Finite Size Lyapunov Exponents, exhibiting the association with attracting Lagrangian coherent structures (LCS). Higher interaction risk was expected at sea surface temperature between 15 and 21˚C. Our study showed that mesoscale turbulence was informative in explaining fisheries-bycatch hotspots and their potential to support dynamic ocean management.