IAP-25-035
Vocal behaviour of killer whales and the dual pressures of ship noise and predation on Arctic marine mammals
Climate change is reshaping the ecosystems of the Canadian Arctic, acting nearly four times faster than in the rest of the world(1). As sea ice declines, the open water season lengthens, leading to an increasing vessel activity(2) and enabling the oceans’ top predator, the killer whale (Orcinus orca), to expand further north and for longer periods each year in Arctic and sub-Arctic Canadian waters(3). These changes add stressors to Arctic endemic species, such as narwhals (Monodon monoceros) and belugas (Delphinapterus leucas), altering ecosystem structure, and function more broadly, as killer whales are known to strongly influence the food web and trophic position through top-down control(4).
Increasing shipping in the Arctic has been documented over the last decade, variating in exposure between regions(2). Ship traffic has been seen leading to changes in communication(5,6) and avoidance behaviour in Arctic toothed whales(7,8), potentially displacing them from ecological important areas and placing additional pressure on species already facing habitat changes from declining sea ice. In addition to stress induced by shipping activities, the increasing presence and vocalizations of predators like the killer whale have been seen inducing avoidance behaviours in marine mammals(9,10). The displacement of endemic Arctic species, resulting from both anthropogenic noise (11) and predator-driven acoustic cues, from critical feeding and breeding grounds has ecological implications, especially for understudied endangered sub-populations with narrow ecological niches11 and directly affects Inuit communities, for whom these species are key cultural and subsistence resources(12).
Yet, Arctic toothed whales are highly mobile marine species inhabiting remote and understudied regions, leaving important knowledge gaps regarding their ecology and responses to stressors, particularly in the context of a rapidly changing climate. Information on these northward expanding killer whales is particularly limited, with no information on their vocal behaviour. Addressing these gaps is essential for understanding their ecological role in a rapidly changing Arctic soundscape.
This project aims to develop an understanding of Eastern Canadian Arctic (ECA) toothed whales’ ecology, with a particular focus on killer whale predation on key Arctic marine mammals such as narwhals and belugas. First, the impact of shipping lanes on Arctic endemic species and how such pressures may displace them from hunting areas vital to Inuit communities will be assessed. This project will then investigate the presence and behaviour of this newly expanding Arctic predator, with emphasis on vocal behaviour analyzed through passive acoustic monitoring (PAM) and acoustic tagging. We will also examine how killer whale occurrence and activity overlap with ecologically important areas of prey species.
Methodology
This project will then investigate the presence and behaviour of killer whales as a newly expanding Arctic predator, with emphasis on vocal behaviour analyzed through passive acoustic monitoring (PAM) recordings and data from acoustic tags attached to killer whales. An automated detection system for each species will be used, and manual corrections will be applied to reduce computational errors. . The PAM analyses will be conducted as part of the CASE collaboration with a placement to work alongside Dr Marianne Marcoux.
Tag data will be collected using sound and movement recording tags attached to killer whales using suction cups(9). Tagging efforts will take place in collaboration with DFO partner Dr Cory Matthews. Acoustic recordings in the tag records will be audited in detail to extract any sounds produced by the tagged killer whales, to create a sound catalogue, including documentation of call types. Kinematic data from the tag data will be calibrated using standard techniques, to enable a decription of the behaviour of the killer whales when they do, and do not, produce sounds.
Project Timeline
Year 1
The first year will include analysis of PAM recordings to quanitify the occurence of toothed whales between 2023 and 2026 on the North and East coast of Baffin Island which is the geographic area most affected by shipping traffice. Noise levels in the frequency bands containing shipping noise will the quantified and related to data from AIS tracks of vessels that transitted the study area during the recording period. Fieldwork for tagging killer whales in the study area will be conducted in Year 1, with the student contributing to fieldwork, calibration of kinematic data, and auditing of the tag recordings.
Year 2
Additional fieldwork for tag data collection with killer whales in the ECA will take place in year two.
Analysis of PAM data will continue with a focus on occurrence and occupancy of killer whales will be assessed using hydrophone data from 2023, 2024 and 2025 in different parts of the ECA. The student will work with the CASE partner also in year 2. Frequency and call type variations (13)will also help defining different activities across regions. To investigate the Atlantic population these killer whales might be part of, the bag of calls approach(14) paired with call type catalogues available to highlight repertoires similarity indices(15) will be used to identify group-specific differences in the usage of call types. The use of machine learning and graph detection signals(16,17) will also complement these first method. Call classification will permit to highlight potential variations across regions(13) and habitat use.
Year 3
Year 3 will focus on quantifying the vocal behavior and kinematic patterns of ECA killer whales from Dtags deployed in years 1 and 2. Kinematic patterns e.g. depth and speed, will be related to vocal behaviour. Variations in call types will be combined with kinematic data from the tags to infer the behavioural context of specific events such as feeding(9). This integration will permit to link acoustic signals to fine-scale behavioural states as well as potential group coordination or feeding events. This would inform on the reliance on acoustic communication for this population, helping to clarify predator-prey interactions and within group interactions.
Year 3.5
This period will focus on thesis writing and examination.
Training
& Skills
References & further reading
1. Rantanen, M., Karpechko, A. Y., Lipponen, A., Nordling, K., Hyvärinen, O., Ruosteenoja, K., Vihma, T. & Laaksonen, A. (2022). The Arctic has warmed nearly four times faster than the globe since 1979. Communications earth & environment, 3(1), 168.
2. Sander, G., & Mikkelsen, E. (2025). Arctic shipping 2013–2022: the traffic has grown, with big variation between regions, seasons and ship types. Polar Research, 44.
3. Ferguson S.H., Higdon J.W., Chmelnitsky E.G. (2010). The rise of killer whales as a major Arctic predator. In:Ferguson SH, Loseto LL, Mallory ML (eds) A little less Arctic. Springer, 117−136.
4. Higdon J. W., & Ferguson S. H., 2009. Loss of Arctic Sea ice causing punctuated change in sightings of killer whales (Orcinus orca) over the past century. Ecological Applications, 19(5), 1365-1375.
5. Vergara, V., Mikus, M. A., Chion, C., Lagrois, D., Marcoux, M., & Michaud, R. (2025). Effects of vessel noise on beluga (Delphinapterus leucas) call type use: ultrasonic communication as an adaptation to noisy environments?. Biology Open, 14(3), bio061783.
6. Tervo, O. M., Blackwell, S. B., Ditlevsen, S., Garde, E., Hansen, R. G., Samson, A. L., Conrad, A. S. & Heide-Jørgensen, M. P. (2023). Stuck in a corner: Anthropogenic noise threatens narwhals in their once pristine Arctic habitat. Science Advances, 9(30).
7. Mayette, A., Shuert, C. R., Hussey, N. E., & Marcoux, M. (2024). Proximity analysis between icebreakers and narwhals in Tasiujaq, Nunavut, Canada. The Journal of Wildlife Management, 88(8).
8. Pirotta, E., New, L., & Marcoux, M. (2018). Modelling beluga habitat use and baseline exposure to shipping traffic to design effective protection against prospective industrialization in the Canadian Arctic. Aquatic Conservation: Marine and Freshwater Ecosystems, 28(3), 713-722.
9. Miller, P. J., Isojunno, S., Siegal, E., Lam, F. P. A., Kvadsheim, P. H., & Curé, C. (2022). Behavioral responses to predatory sounds predict sensitivity of cetaceans to anthropogenic noise within a soundscape of fear. Proceedings of the National Academy of Sciences, 119(13).
10. Matthews, C. J., Breed, G. A., LeBlanc, B., & Ferguson, S. H. (2020). Killer whale presence drives bowhead whale selection for sea ice in Arctic seascapes of fear. Proceedings of the National Academy of Sciences, 117(12), 6590-6598.
11. Hague, E. L., & McWhinnie, L. H. (2024). Narwhal, beluga and bowhead whale responses to marine vessel traffic: a systematic map. Ocean & Coastal Management, 255, 107251.
12. Van Luijk, N., Carter, N. A., Dawson, J., Parker, C., Grey, K., Provencher, J., & Cook, A. (2022). Community-identified risks to hunting, fishing, and gathering (harvesting) activities from increased marine shipping activity in Inuit Nunangat, Canada. Regional Environmental Change, 22(1), 24.
13. Selbmann, A., Deecke, V. B., Filatova, O. A., Fedutin, I. D., Miller, P. J., Simon, M., Bowles, A. E., Lyrholm, T., Lacey, C., Magusdottir, E. E., Maunder, W., Wensveen, P. J., Svavarsson, J. & Samarra, F. I. (2023). Call type repertoire of killer whales (Orcinus orca) in Iceland and its variation across regions. Marine Mammal Science, 39(4), 1136-1160.
14. Vester, H., Hammerschmidt, K., Timme, M., & Hallerberg, S. (2014). Bag-of-calls analysis reveals group-specific vocal repertoire in long-finned pilot whales. arXiv preprint arXiv:1410.4711.
15. Ford, J. K. (1991). Vocal traditions among resident killer whales (Orcinus orca) in coastal waters of British Columbia. Canadian journal of zoology, 69(6), 1454-1483.
16. Roch, M. A., Scott Brandes, T., Patel, B., Barkley, Y., Baumann-Pickering, S., & Soldevilla, M. S. (2011). Automated extraction of odontocete whistle contours. The Journal of the Acoustical Society of America, 130(4), 2212-2223.
17. Brown, J. C., & Miller, P. J. (2007). Automatic classification of killer whale vocalizations using dynamic time warping. The Journal of the Acoustical Society of America, 122(2), 1201-1207.
