‘A devastating impact’: Canada’s wild horses destroy its biodiversity but the public can’t let them go

The horses were deposited on the island in the 1700s by a Boston merchant, along with pigs, sheep and cattle. Photograph: Wirestock, Inc./Alamy

On a narrow crescent of land off the coast of Nova Scotia in the Atlantic Ocean, hundreds of horses run free, galloping along the rolling dunes, their chestnut coats standing out against the white sands and rich blues of the ocean.

After a particularly hard winter, nearly 150 of these horses have died, raising questions about the future of the famed and deeply controversial feral herd of Sable Island.