Ongoing environmental and anthropogenic changes in the Canadian Arctic have raised concerns regarding the capacity of marine mammal populations to adapt to these new and expanding stressors. In order to assess and mitigate potential impacts from stressors like climate change and the expansion of high Arctic marine shipping activities, a better understanding of contemporary marine mammal stocks, behaviour, and movements in the Canadian High Arctic is needed.Efforts will focus on narwhal (Monodon monoceros) and beluga whale (Delphinapterus leucas) populations in the Gulf of Boothia and Cumberland Sound, NU during summer and fall. Killer (Orcinus orca) and bowhead (Balaena mysticetus) whales are also known to inhabit these areas in summer and may be opportunistically sampled as part of this research program. This study will use remotely-piloted aircraft (drones) to collect photographs and video to assess population structure (i.e. age, sex), body condition and behaviour of individuals and groups of whales. Photos will contribute to ongoing photo-identification studies and population abundance estimates. Videos will be used to assess dive behaviour and group dynamics. Additionally, drones will be used to collect blow samples for hormone and genetic analysis.We will use remote tissue biopsy sampling methods to assess genetic relationships, hormone levels, and diet of Arctic whales. Biopsy tissue samples will be collected using custom crossbows, air rifles, and drone-deployed methods. GPS satellite tags will be applied to adult whales to monitor summer movements and provide information on dive behaviour. Location and movement data will be used to monitor behaviour, habitat use, and seasonal migrations. Dive information (time spent at the surface vs. at depth) will be used to inform correction factors to improve population estimates derived from recent aerial surveys conducted throughout the Arctic.Methods will employ least-invasive techniques and technologies to minimize stress on whales and achieve project goals. Drone operations will be led by licensed and experienced pilots and will follow approved standard operating procedures for operating drones near marine mammals. Biopsy sampling and tagging will use remote sampling methods and utilize small boats and drones to deploy biopsy darts and tags on the water or from land. Only trained and experienced operators will be responsible for tagging/biopsy efforts. No animals will be captured or handled during this study. Field studies in Cumberland Sound will be based from the community of Pangnirtung and carried out by two Nunavut Beneficiaries hired through the Pangnirtung Hunters and Trappers Association. Research in the Gulf of Boothia will be carried out by two to four Nunavut Beneficiaries hired through the Taloyoak Umaruliririgut Association. Two Fisheries and Oceans (DFO) staff will accompany the Gulf of Boothia field team during the initial onset of the field work in 2025. Work will be based from a local Inuit hunting camp in Lord Mayor Bay (Lat. 69.661422 Long. -92.671292) for a period of 3-4 weeks in summer. Field crews will rent local Inuit-owned cabins for lodging and Inuit-owned small boats (<10 m length) with experienced Inuit boat operators familiar with the local environment and marine mammal behaviour. Crews will operate daily excursions from the base camp when weather permits.Project Schedule:Cumberland Sound: 01-Jun-2025 to 01-Dec-2025Gulf of Boothia:01-Aug-2025 to 01-Nov-2025