Some 290 km offshore of eastern Nova Scotia, perched at the edge of the continental shelf, lies one of Canada’s most unique islands. A strip of sand 42 km long and 1.3 km wide, Sable Island is home to many unique and even endemic species – species that can be found nowhere else on Earth.
Zoe Lucas, who lived and worked on the island for many years, describes it as “an island of sand, far offshore and exposed on all sides to the full force of the Northwest Atlantic. […] an irreplaceable platform for studying and understanding our atmospheric and marine environments.”
While the island is best known for its population of wild horses, some 400 to 600 strong, these are not the only mammals to call this island home.
Grey seals, which can reach about 2 m long and 350 kg, use this island as a key breeding ground. In December, grey seals arrive on the island to give birth to their pups, who will triple in weight in just 16 days.
Yet, from the 1940s to the 1960s, the species was thought to be all but extinct in south-eastern Canada, following about 170 years of intensive commercial sealing, mostly for the seal’s oil. In the 1960s, only about 100 seals were observed on Sable Island. Then, in the 1960s, the beginnings of marine mammal protection in Canada emerged with the 1966 Seal Protection Regulation under the Fisheries Act. Under this act, sealing permits became mandatory, and quotas dictated how many seals could be taken. These regulations continue to be fine-tuned and were amalgamated into the 1993 Marine Mammal Regulations.
Today, Sable Island is the birthplace of about 85% of grey seal pups born in Canada, with some 80,000 pups being born yearly. As with most wild animals, juvenile recruitment – meaning the number of pups who make it to adulthood – is not very high. Nonetheless, the Sable Island and coastal Nova Scotia populations have increased from approximately 2,300 animals in 1960 to an estimated 380,000 animals in 2017. The total number of grey seals in Canada is about 424,300.
Conservation work to manage commercial sealing and to protect key breeding and feeding grounds, such as Sable Island, is the cause of this rebound. Recent census data suggest the increase in population may be slowing and potentially nearing a plateau as competition for resources, such as food and space, intensifies.
Learn more about Sable Island’s grey seals at https://parks.canada.ca/pn-np/ns/sable/nature/animaux-animals/phoques-gris-grey-seals
Lia Robles Gil is a science communicator who currently resides in Bridgewater. You can find them on Instagram and Bluesky @liaroblesgil.
