A Shark Found in the Salmon River in Idaho… Yes Idaho!

Rare underwater photograph of a Salmon Shark in open water, elusive predator of the Northern Pacific ocean.
Warren Metcalf/Shutterstock.com

Written by Katie Downey

Updated: August 23, 2023

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On Tuesday, August 15, 2023, Idaho Fish and Game went to the Salmon River in Idaho to check out claims that came by email and phone call from numerous people that a shark had washed up on its shore. After careful examination, it appears that the shark is a Salmon Shark (Lamna ditropis), which is bewildering since the river and shark share the same name. After all, salmon sharks are from the Salmon River in Idaho, right?

Some Sharks Can Live in Freshwater

Bull shark facts - a bull shark swimming

Bull sharks have been found 2,485 miles up the Amazon River.

The Salmon River is over 500 miles from the ocean, and Idaho is still a landlocked U.S. agricultural state. The only shark known for its ability to swim up rivers from the ocean is the bull shark. The bull shark is capable of swimming in brackish and even freshwater because of their enlarged kidneys and a gland near their tail. The two help keep salt in the shark’s body while filtering out fresh water. By urinating twenty times more in freshwater than they do in salt water, they can live in freshwater full-time if they want. The salmon shark is not able to filter out freshwater and would die if it tried to live in it.

Salmon Shark Facts

The rare and elusive Salmon Shark, in the open ocean of Alaska.

The rare and elusive Salmon Shark swims in the open ocean of Alaska, not the Salmon River in Idaho.

Salmon sharks are native to the northern Pacific Ocean. They can grow to be 10 feet long and up to 660 pounds. These rarely-seen sharks can also swim at speeds of 50 mph for short bursts. They are related to the mako and great white sharks. Sometimes mistaken for the great white shark and the northern Atlantic porbeagle shark, though the salmon shark’s nose is blunt. Since they live in cold water as low as 34 degrees Fahrenheit, being endothermic, like the great white, keeps them warmer than the water they reside in.

The Truth

Wild westslope cutthroat trout caught and released in the Middle Fork of the Salmon River, Idaho

At the bottom of the story about the salmon shark in the Salmon River is the truth. The salmon of Salmon River are safe from sharks, and there is no reason to be even remotely concerned with sharks in the river. The salmon shark lives 500 miles away in the saltwater ocean and will remain there for the length of its life. The shark found in the Idaho River was a very obvious hoax and a play on words. The small shark was likely caught while an Idaho resident was visiting the ocean and brought back to trick the locals. Somewhere, someone has been laughing about this for days.

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About the Author

Katie Downey is a writer for A-Z Animals where her primary focus is on wildlife, arachnids and insects. Katie has been writing and researching animals for more than a decade. Katie worked in animal rescue and rehabilitation with handicapped cats and farm animals for many years. As a resident of North Carolina, Katie enjoys exploring nature with her son, educating others on the positive role that insects and spiders play in the ecosystem and raising jumping spiders.

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