Bull Sharks In The Great Lakes – Myth Or Fact?

A lot of people have wondered whether Bull Sharks can live in the Great Lakes.

Just like the Loch Ness monster in Scotland, there are now rumors circulating that these creatures have been living around the towns of the Great Lakes for hundreds of years.

Just like with whales, there have been many shark sightings over the years and humans have started to create interesting stories alongside these sightings. 

There have been documentaries on the Discovery Channel that talks about sharks swimming in lakes and rivers. It isn’t impossible, but it is a rare thing to happen.

Yet these shows and stories spark people’s imaginations that they think that a shark could be in the Great Lakes.

In this article, we will be discovering whether seeing a Bull Shark or any shark in the Great Lakes is a fact or just a myth. 

Could A Shark Survive In The Great Lakes?

Sharks need several things to be able to survive, and they are all lacking in the Great Lakes. This is due to the cold temperatures of the lakes and that the majority of sharks need salt water in order to survive.

There is believed to be one species of the shark that is able to survive in the Great Lakes. However, this is a really rare exception. The species of shark in question is the Bull Shark.

This is because the Bull Shark is one of very few species that has physiologically changing abilities. Also, their other abilities are much stronger than other species of sharks as well. 

Typically, you will find a Bull Shark in freshwater all over the world.

Sharks Need Saltwater

For the majority of sharks, they need saltwater in order to survive. Yet the Bull Shark has the special ability to recycle salt in its kidneys, thus making it able to survive in freshwater conditions and environments. 

The Bull Shark is the only species of shark that could potentially live in the Great Lakes waters. For any other species of shark, the lack of salt will cause the salt in the shark’s body to dilute.

This then causes cells in the animal’s body to burst, which then results in the shark dying.

Great Lakes Waters Are Too Cold

Sharks typically don’t like to live in areas that have cold waters. Often sharks will try to avoid any large changes in the water’s temperature.

Once again, Bull Sharks are the only species of shark that could withstand the cold temperatures of the Great Lakes.

Thus, they may end up in the lakes during the end of summer because the water is slightly warmer. 

If the Bull Shark could deal with the temperatures of the lakes in winter, and the lack of good.

Then it is possible that Bull Shark could live in the Great Lakes for a while if it came in from the ocean.

Although, the temperature drops almost to freezing during the winter months, which is too cold for Bull Sharks. 

Lack Of Food

When it comes to freshwater, there aren’t many positives for sharks. The main disadvantage being the lack of food that a shark would typically find in their natural habitat.

In the Great Lakes, the fish are much smaller than the typical prey that sharks hunt for in the ocean. 

With limited prey, they will then struggle to mate during the breeding season. Then on top of that, they would have to deal with the issues and stresses of being in freshwater and the lack of salt.

Hence, the Great Lakes aren’t a great place for a lot of species of sharks. 

When it comes to Bull Sharks, it is known that they hunt for quite large prey. Such as smaller shakers or large bony fish. This kind of prey is very scarce and rare in freshwater areas.

There have been stories that Bull Sharks have attacked humans in the past, but humans aren’t these sharks preferred meal choice. 

With this being said, due to the distribution of Asian Carp through the Midwest and Mississippi waters, this could offer the Bull Sharks a reliable food source. 

Location Of The Great Lakes

It is quite rare for a shark to get so close to the Atlantic coast or near the St Lawrence River. Especially, as the shark would have to swim past and through the lock system of the Niagara Fall.

Hence, the chances of seeing the fins of a shark during the summer seem quite rare and improbable, as the shark would have to swim past many barriers unnoticed. 

Bull Sharks In Lake Superior or Michigan?

There haven’t been any reports of any sharks in Lake Michigan. Although, there have been reports of dead sharks being washed up onto the beaches of Lake Erie and Huron in Ontario.

Yet there is no way to know whether the sharks made their own way there. Or were they planted there. 

Also, there have been no reports of any shark sighting in Lake Superior at all. Bull Sharks will rarely swim beyond the Mississippi basin.

Mainly due to the eclectic barrier found by Chicago. Which is to keep invasive species out. 

Mistaken Identity

It is very probable that the Rock Sturgeon, also known as the Lake Sturgeon is mistaken for a shark. It is a large freshwater fish, which is very new to the Great Lakes.

This is an invasive species, which has a dorsal fin and tail like a shark. Thus people may have seen this creature instead of a Bull Shark, as it does swim close to the surface. 


People have wondered whether there is a chance of a shark being in the Great Lakes. From what we have discussed, the chances of a shark being in the Great Lakes is very low.

It is quite unlikely that you will see a Bull Shark in the Great Lakes, especially as there isn’t much food for them to eat, and a lot of barriers in their way to the lakes.

Hence, these reports of a Bull Shark, may be instead people seeing a Lake Sturgeon who has a similar appearance to a shark.

We hope you have found this article interesting and have a better understanding of what you may have been seeing in the Great Lakes.

Mikayla Adams