Ghost Sharks Are Being Eaten by Leopard Seals in World-First Discovery

Ghost sharks are being eaten by leopard seals off the coast of New Zealand, providing the first evidence the species utilizes chondrichthyans—fish that have cartilaginous skeletons—as a food source.

Krista van der Linde, from the World Wildlife Fund for Nature New Zealand, was lead author of a study looking at leopard seal diets. She said this is the first recorded case of leopard seals feeding on sharks anywhere in the world. "When we founded LeopardSeals.org, I knew we were going to find some interesting things, but this is the next-level of incredible.

"We were blown away to find that sharks were on the menu, but then we also found Elephant fish and Ghost sharks were also being hunted by the leopard seals. These fish have large spines to help protect them from predators and sure enough there were wounds on the leopard seals, sometimes even big spines embedded in their faces, one leopard seal had at least 14 such wounds."

Leopard seals have long slim bodies with a huge head containing enormous jaws. They can grow over 11 feet in length and weigh 1,100lbs. They are known to eat penguins, birds, fish, cephalopods and other seals—the only seals known to regularly hunt warm-blooded prey.

In the study published in December in Frontiers in Marine Science, researchers examined the diets of leopard seals in New Zealand waters by looking at their scats (droppings) and observations of them hunting. They had recorded 39 predation events and collected 127 feces samples and examined what species were being targeted by the seals.

Their findings showed the leopard seals were hunting three species of chondrichthyan—elephant fish, ghost sharks and spiny dogfish. Researchers said this is the first known account of leopard seals hunting and eating chondrichthyans and marks important evidence about the role these seals play in the local ecosystem.

"While this is the first published record of leopard seals feeding on chondrichthyans, the relatively high frequency of occurrence within our [New Zealand] records, and that certain individuals appeared to target this type of prey, indicates that these species could constitute a substantial, or important, part of the diet for some leopard seals in this region," the team wrote.

Study co-author Ingrid Visser, co-founder of LeopardSeals.org, said orca—the apex predator off the coast of New Zealand—are often seen eating sharks. "To know there is another marine mammal also munching on sharks, well, that has implications for the whole food web and our understanding of how it all is interlinked," she said.

leopard seal
Stock photo of a leapord seal. Researchers discovered leopard seals eat sharks. Getty Images