Pacific sleeper sharks, also known as Greenland sharks, are commonly seen in the waters around Alaska and have been known to grow up to 14 feet in length. If a sleeper shark has managed to survive in Lake Iliamna, Wright says it would have an abundance of fish to feed on and no natural predators.

[,,,] Wright says the sleeper sharks have "proven themselves to be very adaptable" and may become the Arctic's top predator due to the effects of global climate change. The sleeper sharks traditionally live in the icy cold depths of the Arctic but have recently been seen by fisherman in warmer waters, including the St. Lawrence River near Quebec's Baie-Comeau. One news report claims the sharks are "Canada's crocodiles" and have allegedly attacked caribou near the mouth of the river. Last year, a conservation group began seeking funds to install webcams in the St. Lawrence that would monitor and help preserve the sleeper sharks residing there.

‘Alaska lake monster’ may be a sleeper shark, biologist says