The value of iron for a seal

This past winter, on a cold, sandy island about 200 miles off the coast of Nova Scotia, a pair of shaggy wild horses supervised the efforts of a small group of seal researchers. “They just stood there and watched us work for a little while,” said Michelle Shero, a marine biologist at WHOI. “They seemed very curious about what we were doing.”?

As the horses looked on, Shero and her team worked carefully to capture, weigh, and measure a mother and pup pair of gray seals. The researchers drew blood and milk samples from the animals and took whisker clippings to analyze later. The stout brown horses, apparently bored with the research process, headed further down the noisy beach, crowded with hundreds of other seals.?

Sable Island, a 12-mile crescent-shaped sandbar, is home to around 500 feral horses that have been living off the island’s beach grass since they were released there in the 1700s. In winter, they are joined by close to 500,000 gray seals—the largest breeding population of gray seals in the world. Shero and her collaborators—including researchers from Texas Tech University, the University of Alaska Fairbanks, and Fisheries and Oceans Canada—spent over a month living in a converted lighthouse keeper’s home on the island, studying gray seal mothers and pups.?

“There are hundreds of thousands of seals, and they’re in every nook and cranny you can think of,” Shero said. “At the house, we’ll often see seals walking past the kitchen window. They’re in the yard, scattered on our walkways, and some of the pups even hang out under the stairs to our sheds. They’re just everywhere.”?