Are There Sharks in the Great Lakes USA?

If you ever find yourself in the Northern USA, you may be wondering…are there sharks in the Great Lakes? With so much deep water, it’s important to understand the lake ecosystem before you decide to go for a late-night swim!

Swimming is a great way to relieve stress and relax, especially in the beautiful wilderness. If you’re used to swimming in nature, you may find yourself frequently asking if the water is safe and if any creatures are lurking where you can’t see them, which can make it unsafe for you. 

Sharks, especially, can cause some concern wherever a large, open body of water exists – whether it’s freshwater or salt water.

To understand if there are sharks in the Great Lakes, it’s important to know a little more about where sharks live, why they live there, and if they’re likely to pose a danger to you or your family.

So, without further ado, let’s dive into the answers for those questions!

Where Do Sharks Live?

You may wonder if there are Great Lakes sharks because the water is open, dark, and deep, and it can be a little scary to go swimming without knowing what lives there. When wondering about sharks, however, it’s essential to know where they can live and if you’re likely to frequent that area.

Like many marine creatures, different sharks can only live in specific environments. While most sharks only live in saltwater, a few breeds can travel from saltwater to freshwater, including the Bull shark.

Learn more:

• Are There Sharks In The Mediterranean?
• Are There Sharks Or Crocodiles In Puerta Vallarta, Mexico?
• Should You Be Worried About Sharks In Costa Rica?

Adapting to different aquatic environments is one factor that has enabled sharks to exist long before humans. Due to their longevity, they have adapted to coastal waters, marine depths, and shallow reefs. Although sharks can be found in coastal environments, the Great Lakes are freshwater, unsuitable to most shark breeds, and far too cold for ideal shark conditions. 

So why do sharks have to live in saltwater habitats? Read on to learn more!

Why Can’t Sharks Live Outside Their Ecosystem?

Many conditions must be met for sharks to find a home in a marine environment. First of all, as previously mentioned, the water usually has to be made of salt. This is the primary reason there aren’t any Great Lakes sharks, as lakes are made up of freshwater. But why is saltwater important for a shark, and couldn’t one migrate to freshwater, even just for a little bit?

Saltwater is important for a shark’s survival because sharks, like most living things, must retain salt in their bodies. Unlike most living things, however, a shark’s salt retention is so instrumental to its survival that without it, its cells rupture and die.

Instead of being lower in saline than the surrounding water, like most other marine life, sharks, instead, have a higher saline content. In fact, their bodies contain such a high concentration of salt that if they were to swim into freshwater, their kidneys wouldn’t be able to diffuse all of it, which would lead to the shark’s death.

Because of this need for saltwater, most species of shark cannot simply enter and adapt to living in freshwater, with a few notable exceptions. One such species of shark which has adapted to living in both salt and freshwater environments is the Bull shark.

Unlike other members of its same species, the Bull shark is adapted to living in both salt and freshwater environments. So, if this shark can do it, does that mean that there’s a chance there might be sharks in the Great Lakes? Fortunately, no. Bull sharks have a unique physical composition that allows them to recycle their body’s salt through diffusion in their kidneys, which keeps them able to live in freshwater.

So if a Bull shark can live in freshwater, like a lake, then why aren’t they a threat to the Great Lakes? The truth is that sharks are all cold-blooded, even the ones adapted to survive in both fresh and saltwater. As a result, they don’t thrive in water temperatures that stay cold for too long. As a result, the Great Lakes, as far north as they are, aren’t ideal water temperatures for sharks. 

Because a shark’s body temperature is dependent on its surroundings, water that stays cold for too long at a time can cause sharks to slow down their swimming and eventually freeze. Therefore, even if a shark is adapted to both salt and freshwater, it still has to pick where it lives with care because if the water is too cold, it will cost the shark its life.

Are the Great Lakes Connected to a Saltwater Source?

Even though sharks live in the ocean and need salt water to live, it may have crossed your mind that if the Great Lakes are connected to the ocean, sharks could wind up in the lakes, even by accident. The lakes themselves are connected to the St. Lawrence River, which does ultimately lead to the Atlantic Ocean. All five Great Lakes are also connected.

So does that mean sharks can swim between bodies of water?

In theory, a couple of the Great Lakes have temperatures that could sustain a Bull shark; however, any sightings of these animals have been proven as hoaxes. There is also a natural deterrent at the base of the St. Lawrence River because the temperature is cold enough to dissuade sharks from swimming into it, even if they can survive in freshwater. 

Are Sharks a Threat to Swimmers In The Great Lakes?

Sharks have suffered in reputation for the last few decades. Due in part to sensationalized media and in part to their toothy appearance, the appearance of a shark fin in the water causes quite a negative stir. Even all the facts about shark habitats in the world may not be convincing, especially given that there have been numerous shark sightings in the Great Lakes over the years.

Despite conjecture, there has never been an officially confirmed shark presence in the Great Lakes. Whether or not you find the Great Lakes shark free, however, there are plenty of facts about the dangers sharks pose to swimmers. In short: these creatures have a bad reputation for relatively little interference with humans.

There are hundreds of species of shark, but so far, the number of species that have been known to attack humans is relatively small. Movies may have taught us that sharks can and do hunt humans as a means of terror and food, but the truth is much less dramatic. Truthfully, sharks’ diets consist mainly of fish and smaller marine animals, and even the biggest species of sharks mainly feed on the occasional seal in addition to fish.

A shark’s diet consists of what is readily available and easy to eat. On the rare occasion that a shark does attack a human, it’s likely due to being confused, injured, or curious. Humans pose far more of a threat to sharks than the other way around. As a result, sharks don’t generally pose a threat to swimmers and boaters, although, as with all wild creatures in nature, it’s best to coexist peacefully and respectfully in water.

Are the Great Lakes Safe for Swimming?

Even if Great Lakes sharks aren’t your primary concern, there are other considerations for swimming in some of the USA’s largest bodies of inland water. Unlike most smaller lakes, the Great Lakes contain currents that run parallel to the shore and rip currents that run perpendicular to it. These currents cause many drowning deaths yearly, far more than the number of deadly national shark attacks.

Of course, there will always be a risk of drowning in any body of water, so it’s vital to check current guides and have emergency plans in place should you or your loved ones find yourselves in troubled waters.

Even if there aren’t sharks in the Great Lakes , there are plenty of other wildlife to see and be aware of as you spend your time lakeside. There are numerous types of fish to see and try and catch, but wolves and eagles also exist.

Are There Sharks in the Great Lakes? And….What If You See One?

Even though by now you know that there aren’t any Great Lakes sharks, you probably want to know what to do in case you feel like you’ve spotted one.

If you think you see a shark in the Great Lakes, firstly – don’t panic. Consider the possibility that what you’re seeing is one of the many large fish that live in the water. Make sure to remind yourself of the ideal living conditions for sharks, and breathe. 

Remember: there hasn’t been a confirmed shark living in the Great Lakes! 

Swimming in nature comes with its list of risks, from wildlife to currents and even sun damage. Thankfully, you probably won’t have to worry about sharks if you spend time in the Great Lakes. The cold water temperature and low saline content are enough to keep them away. So enjoy your time in nature, and leave your shark worries at the beach.