Is Alaska's Lake Iliamna monster actually a Pacific sleeper shark? It's a hypothesis that's been debated in these pages. In fact, it's possible that other legendary lake monsters actually are Pacific sleeper sharks, too. More research to test this theory was planned for this summer.
A summer solstice revelation from King Cove Lagoon corroborates the Pacific sleeper shark theory.
Wednesday morning, Chris Babcock of King Cove, Alaska, spotted something in the shallow water of the King Cove Lagoon, a lake of brackish water. Closer inspection revealed a Pacific sleeper shark rolling and thrashing around. The shark's antics were filmed and posted on YouTube -- you can see that video below.
According to Babcock, the fish approached him when he entered shallow water, but later moved to deeper water.
Every time you have a close look at this species, it surprises you. The behavior Babcock described has not been reported for sleeper sharks. Indeed, this species looks pretty confused and unshark-like.
Sleeper sharks as a species take advantage of climate change and have become a dominant predator in the North Pacific and Arctic oceans. They may also be capable of using freshwater and salmon-filled lakes for food and refuge.
Sleeper sharks in Alaska reach 20 feet and weigh up to 4 tons, feeding on flounder, pollock and cephalopods and marine mammals. “Pacific sleeper sharks, which are also known scavengers, can glide through the water with little body movement and little hydrodynamic noise making them successful predators,” according to Wikipedia. “They feed by suction and cutting of their prey. They have large mouths that can inhale prey and their teeth cut up any pieces that are too large to swallow. They show a characteristic rolling motion of the head when feeding.”
Nearly every marine species in the Arctic has been found in the stomachs of these sharks, which makes sleepers a unique predator. Scientists who examined a dozen Greenland sharks from Iceland found that six sharks contained remnants of marine mammals, accounting for a quarter of the total mass of stomach contents and, perhaps, a majority of the energy ingested based on the energy content of marine-mammal blubber.
Bruce Wright is senior scientist at the Aleutian Pribilof Island Association, where he's worked sinc 2005. He's the author of "Ecology and Conservation of Alaska's Predators" and "Alaska's Great White Sharks." Reach him at brucew(at)apiai.org. Used with permission.