Scars from above

We will explore the use of aerial imagery to assess large whale entanglement and its energetic consequences.
Entanglement in fishing gear is a major threat to large cetaceans such as humpback whales. In the North Atlantic, up to half of all humpbacks bear the resulting scars and entanglement is a leading cause of anthropogenic mortality.

However, knowledge gaps still remain in the field. Entanglement rates are typically calculated by assessing scars from photos taken from boats, in which only a small proportion of the whale’s body is visible. Furthermore, the true cost of entanglement is almost certainly greater than direct mortality. Fishing gear restricts movement, which may hinder swimming or feeding. Therefore, entanglement likely has energetic consequences.

In this project, we will investigate the use of aerial images taken by drones (aka unoccupied aerial vehicles) to address these knowledge gaps for humpback whales. We will focus on Steingrímsfjörður, a remote fjord in the Icelandic Westfjords. This area is a coastal humpback feeding ground in summer and autumn, allowing us conduct all of our fieldwork from land.

Leading on from recent work from other research groups, we have three specific aims:

  1. Investigate the suitability of drone aerial images to assess entanglement scars on humpback whales.
  2. Determine entanglement rates for different age classes.
  3. Determine the impact of entanglement on individual body condition.
Achieving this will require a huge collaborative effort. In Steingrímsfjörður, we will work with Judith Scott, a whale-watching guide for Láki Tours, who has amassed a huge photo-identification data set in recent years. We’ll also continue to work with the University of Iceland. Dr Charla Basran, co-director of the university’s Research Centre in Húsavík, will supervise this project. Meanwhile, we also plan to use drone images collected in Skjálfandi Bay by Maria Glarou, a PhD student, and Prof. Marianne Rasmussen, co-director of the research centre.

This project is still at an early stage, so stay tuned for updates and developments!