Standard Presentation Australian Marine Sciences Association Annual Meeting 2023

Using Aerial Imagery to Estimate Non-lethal Anthropogenic Scarring Rates in the East Australian Humpback Whales (#314)

Stephanie Stack 1 2 , Emily Gregory 1 , Barry McGovern 1
  1. Pacific Whale Foundation Australia, Hervey Bay, QLD, Australia
  2. Griffith University, Gold Coast, QLD, Australia

The East Australian humpback whale population has made an impressive recovery from the historical threat of commercial whaling. However, new anthropogenic threats such as entanglement in fishing gear and vessel strikes pose a significant risk to their continued population recovery. A scar assessment to understand the extent of these threats, was conducted between June and September 2022 in Hervey Bay, Queensland to assess the degree of entanglement and vessel related scars on individual whales. Images of humpback whales in the bay were extracted from high resolution videos taken using an unoccupied aerial system (drone). The whale’s dorsal surface was divided into five sections, and each was assigned a scarring code based on the presence or absence of scars associated with entanglement or vessel strikes from quality graded images. This allowed for the calculation of minimal, conditional, and maximal scarring proportions (6.1%, 6.3%, 9.8%) for 101 assessed individuals. The findings of this study will aid in management measures to ensure the continued recovery of the East Australian humpback whale population. Future studies will integrate body condition indices to quantify the energetic costs of entanglement and vessel strikes, providing a more comprehensive understanding of the impact of these threats on the population.