Field Update: Seals and Satellite Tags

When people think of Manitoba, they don’t often think of the ocean, yet the northernmost part of our province is the coast of Hudson Bay. It is a unique ecosystem home to marine mammals such as belugas, seals, and polar bears. Hudson Bay is the world's most southern arctic and subarctic ecosystem and is sensitive to a changing climate and human activity. Our conservation team conducts research along Hudson Bay in the Churchill region to better understand this fascinating ecosystem.

The most recent trip this May was focused on harbour seals, one of the three species found near Churchill (ringed seals and bearded seals are the other two). Harbour seals are found in the Arctic but are more adapted to warmer waters. They also are one of the few seal species that use rivers and freshwater.

Our team spent 15 days working with partners to understand how harbour seals use the marine and freshwater environments around Churchill. This work builds on research that we previously led showing that the number of harbour seals has increased in the area since the 1990s. This seal population increase is what you would expect in a region like Churchill that is warming due to climate change.

Learning about seal behaviour, movement, diet, and population numbers provides many benefits both to Manitobans and seals. The research will provide information to wildlife managers so that seals and people can coexist, provide insight into how these northern seals can survive, give a baseline so new threats can be detected and reduced, and provide local ecotourism operators with more information to share with visitors.

This spring, our team was focused on putting satellite tags on harbour seals. They successfully tagged four harbour seals, three males and one female. Because we were working on the sea ice, this was a bit different than you may have seen on season 2 of Arctic Vets (Episode 2 @ 12.39). The sea ice can be dangerous, and it is prime polar bear habitat, so the team was assisted by a local guide and was accompanied by a polar bear monitor. 

Our team sets up a special net perpendicular to the ice edge to capture the seals

To capture each seal, the team works from the floe edge, where the ice meets the open water. They stretch out a special seal net perpendicular to the ice edge and monitor it until a seal swims into the net. Once the seal is in the net, it is quickly pulled to the edge and onto the ice. Once out of the net the team works as quickly as possible to take measurements, and samples, and to attach two types of tags onto the seal. One provides a lot of detailed information for a few months before it falls off and the other only transmits a location when the seal is out of the water but will last about two years.

When handling any animal, our team does everything possible to minimize stress on the animal. They spend around 30 to 50 minutes with each seal, and an APC veterinarian is part of the team to administer sedation if needed, monitor animal health, and assist with sampling and tagging. All research projects are reviewed by animal care councils and the research ethics review committee here at APC.

The team carefully extracts a seal from the bag used to safely weigh it

Access to wild seals is a rare opportunity, so our team maximizes the scientific benefit of each encounter by collaborating with other research organizations that can benefit from samples, and data, or provide training opportunities. On this trip, APC partnered with the Department of Fisheries and Oceans, Manitoba Hydro, and students from the University of Manitoba and the University of Victoria.

Over the next few months and years, our team will continue to monitor these tagged seals to learn more about their movements and behaviour in western Hudson Bay. This seal research is part of a larger overarching effort to better understand the Western Hudson Bay ecosystem. With other projects such as the invertebrate sampling using DNA barcoding in the same western Hudson Bay area and Beluga Bits, the research and conservation projects APC contributes to in Churchill are connected.

Understanding the western Hudson Bay ecosystem and recognizing changes helps provide valuable data to support the establishment of a National Marine Conservation Area (NMCA) and adjacent terrestrial Indigenous Protected and Conserved Areas in the region. NMCAs are established and managed to protect and conserve representative marine areas for the benefit, education, and enjoyment of the people of Canada and the world.

This research, and all the work that the APC conservation and research team participates in, contributes to the understanding and protection of our natural heritage. You can also help by reducing your carbon footprint to reduce climate warming, getting involved in initiatives to protect northern ecosystems like the Seal River Watershed IPCA, or supporting the work of the Conservation and Research team by donating to the Wildlife Conservation Fund.