PhD defence: Helena Sofia Gomes Costa

Thesis title​​​:

Whale exhale: Innovating pathogen surveillance in free-swimming cetaceans through novel field and in vitro experimental techniques

Trial lecture topic:

The use of drones in ecological and conservation research

Evaluation Committee:

• Professor Patricia Arranz Alonso, Department of Animal Biology, Soil Science and Geology, University of La Laguna, Spain
• Postdoctoral Fellow Javier Sánchez Romano, One Health project, Institute of Zoology (IoZ), UK
• Professor Hetroney Mweemba Munang’Andu, Fakultet for biovitenskap og akvakultur, Nord University

Supervisory Committee:

• Main supervisor: Associate Professor Courtney Alice Waugh, Fakultet for biovitenskap og akvakultur, Nord University
• Co-supervisor: Senior Researcher Jorge Manuel de Oliveira Fernandes, Department of Renewable Marine Resources, Institute of Marin Sciences (ICM-CSIC), Spain
• Co-supervisor: Associate Professor Susan Bengtson Nash, Department of Environmental Sustainability and Management, Griffith University, Australia

Thesis summary​:

When three killer whales (Orcinus orca) were sighted in Northern Norway, in winter 2023, displaying severe signs of infectious disease, it became clear how difficult it is to assess the health status of wild cetaceans - and how urgent is the need for novel methods to sample live whales, in the region.

To address this, a consumer drone was validated for blow sampling, offering new opportunities for cetacean health assessments. This method was subsequently employed to sample four cetacean species in the North-East Atlantic, leading to the first detections of cetacean morbillivirus (CeMV) in Norway, including in humpback (Megaptera novaeangliae), sperm (Physeter macrocephalus), and long-finned pilot whales (Globicephala melas). Herpesviruses were detected in co-infection with CeMV, while no Brucella spp. or avian influenza virus were detected. Further, using fibroblasts cultured from wild killer whales, it was shown that high exposure to Persistent Organic Pollutants increased CeMV replication in vitro, highlighting the potential role of these immunotoxic pollutants in exacerbating infection severity in the wild.

Collectively, this work establishes novel methodologies for live cetacean health monitoring and underscores the importance of integrative approaches to assess risks to marine mammals in the face of rapid environmental change.