Can Bull Sharks Live in Freshwater? - Dutch Shark Society (2022)

The bull shark is one of the most dangerous shark species in the world. Also known as the Zambezi and the Lake Nicaragua shark, it’s also one of the most versatile. It is often found in the murky waters of estuaries and river mouths and frequently comes into contact with humans.

Because of this proximity, the bull shark is responsible for more shark attacks on humans than almost any other, apart from the great white.

Can Bull Sharks live in freshwater? One of the main reasons the bull shark comes closer to shore than other species is its ability to tolerate freshwater.

Most sharks can exist only in saltwater habitats. If a great white shark strayed too far up a river system and into freshwater, the higher level of salinity inside its body would cause it to bloat.

As freshwater entered through the gills, it would dilute the salt levels inside the shark, causing its cells to expand and rupture.

However, the bull shark has adapted to live in both salt and freshwater environments. They use several processes to regulate their bodily fluids and internal salinity levels.

Can Bull Sharks Live in Freshwater?

Can Bull Sharks Live in Freshwater? - Dutch Shark Society (1)

Bull sharks can live quite comfortably in 100% fresh water and occur in tropical river systems all over the world.

Although they usually frequent estuaries and river mouths, they occasionally venture further inland. In 1937, fishermen in Alton, a city situated 15 miles north of St. Louis on the Mississippi River, caught the culprit responsible for stealing their catch. To their surprise, it turned out to be a bull shark!

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Bull sharks have also been found in freshwater river systems and lakes in other parts of the world, including South America and Africa. Bull sharks have even been caught as far as 2,500 miles from the Atlantic Ocean!

Bull sharks are notoriously aggressive in the ocean, but very few shark attacks have been reported in freshwater environments. This could be because it’s generally younger bull sharks that are attracted to the freshwater, and they aren’t large enough to take on prey the size of a human being.

(Video) Bullsharks can swim in both salt and freshwater | Oceana

Why Can Bull Sharks Survive in Freshwater?

Bull sharks have developed an intricate process that aids salt retention and helps them adapt to freshwater living.

The bull shark’s gills play a critical role, absorbing sodium and chloride from the environment to regulate internal salinity levels.

The kidneys are also vital, enabling salt to be reabsorbed into the bloodstream. Bull sharks also adjust their urine output in response to water salinity, urinating 20 times more in freshwater than in the ocean.

The last quiver in the bull shark’s biological bow is an unusual rectal gland located just in front of the caudal fin.

All sharks possess this gland which, scientists believe, is made of “specialized salt-secreting tissue.” In other words, it removes excess salinity from the shark’s body.

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This gland is present in all sharks, but its function isn’t fully understood. It appears to play a critical role in controlling the shark’s internal concentrations of water and salt.

In bull sharks, this has evolved to the extent that they can live for long periods in freshwater. Quite why they made such adaptations is unclear, although scientists believe it may be a kind of a survival mechanism.

Although mature bull sharks have few predators, young bull sharks can fall prey to other shark species, including the tiger and the sandbar. Neither of these species is euryhaline, so they can’t adjust to different salinities as the bull shark can. Living in freshwater would therefore protect younger bull sharks from predation.

How Long can Bull Sharks Live in Freshwater?

Theoretically, bull sharks should be able to survive in freshwater for their entire lives, but there is no evidence to prove this. It appears that the bull shark moves into more coastal areas to breed and reproduce.

Bull sharks that were trapped when a dam was constructed on the Rio Bayano river in 1976 survived for around four years. This proved that they could “survive in freshwater for long periods,” but whether they could live there forever is still up for debate.

Can Bull Sharks Live in Freshwater Forever?

One study of the bull shark distribution in the Indian River Lagoon in Florida found that young bull sharks, measuring between 90 to 190cm (35” to 75”), occupied the freshwater river system all year round.

Adult-sized sharks, on the other hand, were only found in freshwater in the late spring and early summer. Not only that, but all these mature sharks were female, and the majority were either pregnant or carrying eggs.

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Very young or neonate bull sharks were also found in the river systems during spring and summer but, when the temperatures dropped in autumn, moved to more brackish waters.

When they found the bodies of bull sharks in Lake Bayano, researchers initially thought they’d starved to death, but this seems unlikely.

Studies of bull sharks’ feeding habits indicate they’re opportunistic and indiscriminate feeders that “will consume almost any kind of animal matter.” Therefore, the chances of a bull shark starving to death are decidedly slim.

Quite why the Lake Bayano bull sharks died so young is unclear. It may suggest that bull sharks aren’t suited to permanent freshwater residency despite their physiological adaptations.

Are There Bull Sharks in Freshwater Lakes?

Bull sharks occur in just one freshwater lake – Lake Nicaragua in Central America. Covering over 8,000 ㎢, this vast lake is often referred to as “the sweet sea” and resembles the oceans with its waves and islands.

Until recently, the so-called Lake Nicaragua shark was thought to be a distinct, land-locked species of freshwater shark. There appeared to be no way for an 11-foot-long shark to traverse the shallow river that connects the lake to the Caribbean Sea, suggesting it was stuck in a freshwater environment.

This was clear evidence that a bull shark could survive in a lake – or was it?

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Can a Bull Shark Survive in a Lake?

A bull shark can survive in a lake but doesn’t appear to live there permanently.

By tagging the bull sharks in Lake Nicaragua, researchers have discovered that they travel back and forth between the lake and the sea relatively frequently. This movement is called diadromous migration.

Can Bull Sharks Live in Freshwater? - Dutch Shark Society (2)

Besides Bull Sharks, What Other Shark Species Can Live in Freshwater?

Aside from the bull shark, which frequents tropical rivers all over the world, five other shark species can survive in freshwater.

#1 Ganges Shark

As its name suggests, the Ganges shark is found in the Ganges and Brahmaputra Rivers of Bangladesh and India. Critically endangered, the Ganges shark is similar to the bull shark in appearance but notably different in its physiology.

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Unlike the euryhaline bull shark that moves between different levels of salinity, the Ganges is a freshwater shark that rarely ventures into the open ocean. Their range rarely extends beyond tidal areas where there’s a combination of muddy waters and a low salinity.

There is little information available about the rare and secretive Ganges shark, although scientists think both the Borneo and Irrawaddy River Shark may belong to the same genus.

#2 Northern River Shark

There are thought to be just 250 mature Northern River sharks in the world, all of which spend their time in the bays, estuaries, and tidal rivers of Papua New Guinea and Australia.

Preferring murky waters and muddy bottoms, this unusual species relies on electrical impulses to find its prey.

The head of the Northern River shark is covered with special electroreceptors known as ampullae of Lorenzini. These sensing organs enable the shark to detect changes in water temperature and “sense electric fields in the water.”

Like young bull sharks, it appears to be the newborn and juvenile Northern River Sharks that frequent the freshwater, while the mature sharks remain in more coastal environments.

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#3 Speartooth Shark

Like the bull shark, the speartooth is a euryhaline species that can tolerate freshwater as easily as it does seawater. It inhabits tropical rivers, estuaries, and coastal marine waters in Australia and Papua New Guinea.

Its behavior is similar to that of the bull shark, with the juveniles venturing much further up the river system than the adults.

#4 Pondicherry Sharks

This shark species is so rare it was thought to be extinct for over 40 years. Sometimes known as “the lost shark,” there was no evidence of the Pondicherry’s existence until one was discovered at a Sir Lankan fish market in 2019.

The Pondicherry shark is so rare we know very little about the species, except that it appears to migrate between salt and freshwater areas only outside the breeding system.

#5 Greenland Shark

The enormous Greenland shark is a constant source of surprises. It lives for hundreds of years, can withstand depths over 7,000 feet and frigid waters of just 28℉. Not only that, but Greenland sharks can also tolerate freshwater!

There have been reports of Greenland sharks in the cold, deep waters of Canada’s Saguenay and St Lawrence rivers. Very little is known about how long the Greenland shark can survive in freshwater, or about its migratory patterns to and from these river systems.

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Final Thoughts

The bull shark is one of a handful of shark species that can tolerate freshwater and traverse between river systems and the ocean. Known as a euryhaline shark, the bull shark has a special renal gland that aids salt retention and enables it to survive in different salinities.

As few other shark species have this ability, it seems likely that the bull shark developed it as a survival mechanism. Younger bull sharks can effectively “hide” in freshwater, out of reach of saltwater species like the sandbar and tiger shark.

Although the bull shark can survive in freshwater, it doesn’t appear to stay there forever, preferring to move towards more coastal zones as it matures.

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Nicky Hoseck

Nicky is a British adventurer and animal lover who spends her time exploring the natural world and writing about her experiences. Whether on horseback, underwater, running, hiking or just standing with a fishing rod in hand, she embraces everything her adopted home of South Africa has to offer.

(Video) Sharklab Malta World Ocean Day 8 June 2020


Can Bull Sharks Live in Freshwater? - Dutch Shark Society? ›

The bull shark is one of a handful of shark species that can tolerate freshwater and traverse between river systems and the ocean.

Where does the bull shark live? ›

Bull sharks are found in coastal waters all over the world. In the United States they are found off the East Coast and in the Gulf of Mexico. Unlike most sharks, bull sharks can survive in freshwater for long periods of time. They have even been found in the Mississippi and Amazon Rivers.

Can bull sharks live in brackish water? ›

Bull sharks are the exception to this rule – they can tolerate brackish and even freshwater conditions because of their advanced ability to osmoregulate, or maintain a constant concentration of water in their bodies despite changing salinity levels in the water.

What shark can live in both saltwater and freshwater? ›

Bull sharks can thrive in both salt and fresh water and can travel far up rivers. They have been known to travel up the Mississippi River as far as Alton, Illinois, about 1,100 kilometres (700 mi) from the ocean. However, few freshwater human-shark interactions have been recorded.

What sharks can survive in freshwater? ›

Join us as we discover just which sharks can live in freshwater and how they do it.
  1. Greenland Shark.
  2. Pondicherry Shark. ...
  3. Speartooth Shark. ...
  4. Northern River Shark. ...
  5. Bull Shark. A bull shark. ...
  6. Ganges Shark. The Ganges is one of the most populated rivers in the world. ...
Nov 12, 2021

Can a bull shark be in a lake? ›

Bull sharks can survive in both saltwater and freshwater, and have been known to frequent the lake.

Can bull sharks live in freshwater and saltwater? ›

As freshwater entered through the gills, it would dilute the salt levels inside the shark, causing its cells to expand and rupture. However, the bull shark has adapted to live in both salt and freshwater environments. They use several processes to regulate their bodily fluids and internal salinity levels.

Do bull sharks need salt water? ›

Sharks must keep salt in their bodies to survive, and most can live only in salt water. But bull sharks have developed special adaptations—the way their kidneys function and special glands near their tails—that help them keep salt in their bodies even when they're in freshwater.

What do bull sharks eat in freshwater? ›

When the bulls hit freshwater, their diet gets a little more interesting. They feast on tarpon fish, crabs, shrimp, squid, sea urchins, turtles and sawfishes.

Where are bull sharks found in freshwater? ›

Bull sharks have been found in freshwater around the world: thousands of miles up South America's Amazon, in Central American lakes and as far up the Mississippi as Illinois, according to National Geographic.

What is the biggest bull shark ever recorded? ›

According to the International Game Fish Association (IGFA), the largest bull shark caught on rod and reel weighed 771 lb. 9 oz. (347 kg) and was caught near Cairns, Australia.

How many sharks can go from saltwater to freshwater? ›

All in all, there are more than 400 species of sharks that can move between saltwater and fresh. As for the hippos, they were not impressed.

What happens if you put a shark in freshwater? ›

In freshwater, which has no salinity, a shark will take in too much water. This can lead to a dulling of the senses, bloating, and eventually, death. Furthermore, since sharks do not have a swim bladder like fish, they rely completely on their livers to help them stay buoyant.

How much does a bull shark cost? ›

BULL SHARK Starting At: $248.75DOG SHARK Starting At: $238.80
Bull Shark Mount - Fish Replica / Taxidermy / Marine Decoration.Dog Shark Mount - Fish Replica / Taxidermy / Marine Decoration.
HAMMERHEAD SHARK Starting At: $225.00LEMON SHARK Starting At: $225.00
22 more rows

Are bull sharks aggressive? ›

Bull sharks are aggressive, common, and usually live near high-population areas like tropical shorelines. They are not bothered by brackish and freshwater, and even venture far inland via rivers and tributaries.

Could bull sharks survive in the Great Lakes? ›

But Bull Sharks are able to recycle salt in their kidneys, maintaining salt levels critical to its survival. Yet even the Bull Shark would not be able to make its way into the Great Lakes watershed and survive! The water temperature in the Great Lakes is far too cold for most sharks (including the Bull Shark).

Can bull sharks survive in cold water? ›

Bull sharks prefer living in warmer waters and do not usually occupy cold water regions. They like the water temperature to be at least 68℉ or more. Moreover, they prefer shallow waters or freshwater regions where the water is brackish.

Has a shark been found in lake Erie? ›

There are no sharks in Lake Erie," pronounces Officer James Mylett of the Ohio Department of Natural Resources (ODNR).

Why are there no freshwater sharks? ›

It is exceptionally hard for sharks that have evolved in saltwater to transition to freshwater due to the lack of salt. Without retaining salt inside of their bodies, the sharks cells can rupture, causing them to bloat and die.

How long can a bull shark survive out of water? ›

Death will follow between four and six minutes after that. Without oxygen, most large shark species will suffer a very similar fate. Hypoxia will rapidly cause brain damage, so while an oxygen-deprived shark may appear to be still alive, it will likely rapidly suffer irreversible damage in just a few minutes.

What is the farthest inland a bull shark has been found? ›

The furthest inland a bull shark has ever been seen in North America is Alton, Ill. Alton sits along the Mississippi River about 15 miles north of St. Louis, and 1750 miles from the Gulf of Mexico.

How old is a 7 foot bull shark? ›

Matures at approximately 14-18 years of age (about 7 feet) and is estimated to live longer than 30 years.

How strong is a bull shark? ›

The bull shark's bite packs quite a punch, at a whopping 5,914 Newtons (1,330 pounds/foot). Compared to the 4,000 Newtons of a great white, and the tiger shark, at 3,300 Newtons, the bull shark's bite is incredibly powerful!

How long does a bull shark live? ›

Bull sharks reach sexual maturity between the ages of 8 and 10. They breed in brackish waters in summer months. Females give birth to a litter of between one and 13 live young after a 10 to 11-month pregnancy period. Bull sharks can live to be at least 14 years old.

Why do bull sharks bump before attacking? ›

"Bump and bite" encounters involve a shark circling and often bumping a human before the attack, possibly to assess the size and strength of its prey. And in "sneak" attacks, the shark will strike without any warning.

What is the bite force of a bull shark? ›

In a direct comparison, they report that a 9-foot-long bull shark has a bite force of 478 pounds, while an 8-foot-long great white has a bite with 360 pounds of force. "An 18-foot-long great white will still have a more powerful bite than an 11-foot bull shark, just by virtue of its size," Motta says.

Do bull sharks jump out of the water? ›

Breaching is not a behavior typically associated with bull sharks, and has led to species misidentifications in the past. The behavior was observed on 18 occasions over a two year period in the study site, including a day in which 11 breaches were observed in a small estuarine creek.

How far up river can a bull shark go? ›

The two scoured hundreds of bull shark reports and research to understand the movements of these mysterious creatures. They have now published their findings and officially confirmed that bull sharks travel more than 1,000 miles up the Mississippi River! And just when you thought it was safe to go back in the water…

Are there sharks in the Great Salt Lake? ›

Are There Sharks in the Lake? There have been many rumors of sharks in the Great Salt Lake. There have also been rumors of an old sea captain capturing whales and transporting them from the ocean to the lake. However, no one has proven these claims.

Is a tiger shark bigger than a bull shark? ›

Bull sharks are quite a bit smaller than the massive tiger shark. The bull shark is one of the larger predatory sharks around, although it isn't nearly as large as the tiger shark. Most bull sharks measure between 7-11 feet long when they reach maturity, although rare individuals can get longer.

What's the biggest bull shark caught in freshwater? ›

In the Breede River in South Africa, a team of scientists had landed a 13-foot 1000-pound female shark in the river, and it set the world record as the largest Bull Shark ever caught. It was released back into the river, causing controversy with many of the locals.

How shallow of water can bull sharks swim in? ›

And that's fine. Everybody can make their own personal decision, but realizing that sharks can get into water as shallow as five of six feet deep is something that people need to realize.”

Do lemon sharks like humans? ›

Since these sharks are gentle animals and generally non-aggressive towards humans, they are very popular shark divers. There has never been a recorded fatality due to a Lemon Shark bite and most bites are the result of the shark being spooked.

Can lemon sharks live in freshwater? ›

The lemon shark is commonly found in subtropical shallow water to depths of 300 feet (90 m) around coral reefs, mangroves, enclosed bays, sounds and river mouths. However, this species do not venture far into freshwater systems.

Do bull sharks eat humans? ›

Hunting. They are found cruising the shallow, warm waters of all the world's oceans. Fast, agile predators, they will eat almost anything they see, including fish, dolphins, and even other sharks. Humans are not, per se, on their menus.

Are bull sharks blind? ›

Compared to their cousins the tiger and blue sharks—whose large, dark, disc of an eye make them such efficient sight hunters—the bull shark is as blind as Magoo. They often hunt in murky waters where visual acuity is less of a factor.

Why do bull sharks swim up river? ›

Heithaus, of Florida International University, speculates that "probably the biggest reason is that [freshwater tolerance] allows the juveniles, the little guys, to be in a place that's relatively safe from being eaten by other sharks." Adult bull sharks likely gain their own competitive advantages from salt retention.

How long can a bull shark live out of water? ›

Death will follow between four and six minutes after that. Without oxygen, most large shark species will suffer a very similar fate. Hypoxia will rapidly cause brain damage, so while an oxygen-deprived shark may appear to be still alive, it will likely rapidly suffer irreversible damage in just a few minutes.

If you wanted one of nature’s ultimate hunters in your home, would it be possible to have a tiger shark aquarium?

In fact, the tiger shark is, by average size, the third-largest fish in the ocean, coming in behind the biggest, the whale shark (Rhincodon typus), the basking shark (Cetorhinus maximus) at number two, and the great white shark (Carcharodon carcharias).. Sand tiger sharks also tend to have a far more docile nature than tiger sharks (it has no confirmed human fatalities), making them more relaxed aquarium inhabitants.. The sand tiger sharks also generally inhabit cooler waters than tiger thanks which, depending on the location, could make it more economically viable to keep them compared to the costs of heating large volumes of water for a tiger shark’s requirements.. As we already mentioned, at the time of writing, the Georgia Aquarium has a tiger shark which it keeps in its massive exhibit with great hammerhead sharks, silvertip sharks, and sand tiger sharks.. However, animals like the tiger shark are so difficult to keep successfully that, on balance, it seems to this author that they do not belong in a tiger shark aquarium and should be studied exclusively in their natural environment.

Bull sharks have an even fiercer bite than great whites, but we're still more dangerous to them than they are to us. Learn more with these bull shark facts.

They may lack the widespread name recognition of great whites , but bull sharks are also considered a potential threat to humans who venture into the ocean, with more than 100 historical attacks linked to their species.. At the same time, however, a beachgoer is more likely to be killed by rip currents or lightning than by a bull shark (or by any other shark), and these ancient fish face far more danger from us than we do from them.. The species can bite with a force of 5,914 Newtons, the study found, which is more powerful than the bite of 12 other sharks and sharklike fish the researchers used for comparison—including the great white shark and the great hammerhead.. Rainervon Brandis / Getty Images. While most sharks are limited to marine habitats, bull sharks can live for long periods and even reproduce in either freshwater or saltwater.. After a roughly 11-month gestation period, the mother gives birth to a litter of one to 13 pups, often opting for a freshwater or low-salinity part of her range, such as coastal lagoons, river mouths, or estuaries.. While adult bull sharks have no natural predators (aside from humans), their pups can fall victim to other sharks.. Great whites are relatively rare in New Jersey, especially in inland waterways, and two of the attacks took place in a creek in Matawan, located about 10 miles from the ocean.. Bull sharks are much more commonly found in habitats like this, and although great whites have more of a reputation for attacking people, bull sharks are also considered one of the most dangerous shark species for humans.. Research suggests sharks do not see humans as enticing prey, and most "attacks" are actually exploratory bites, after which the shark typically moves on.. That said, for large predators with powerful bites like bull sharks, even a test bite like this can fatally wound a person, so they should be treated with caution and respect.. While sharks kill fewer than 10 people globally per year, people kill an estimated 100 million sharks every year, largely due to fishing, finning, and accidental bycatch.. Rodrigo Friscione / Getty Images. Bull sharks are still a common species, found in many warm waters around the world, but even these formidable and flexible predators are at risk from humans.. The IUCN says the bull shark is "caught as target and bycatch in artisanal, industrial, and recreational fisheries across its range with multiple fishing gears including gillnet, longline, and trawl.. These entrap juvenile bull sharks in both freshwater and saltwater estuaries.

Their ability to tolerate freshwater is rooted in salt retention. Sharks must retain salt inside their bodies. Without it, their cells will rupture and cause

22 related questions found Instead of drinking water, the shark absorbs some seawater (and salt) through its gills .. Though there are 43 species of sharks that will occasionally take short swims through freshwater looking for food, most sharks cannot live in freshwater for sustained periods of time.. ... For now, it is unlikely to find Bull Shark anytime in Lake Michigan because of the low water temperature .. Secondly, most sharks can only tolerate saltwater, or at the very minimum, brackish water, so freshwater rivers and lakes are generally out of the question for species such as great white sharks, tiger sharks, and hammerhead sharks.. According to National Geographic, a great white shark typically can't survive for very long in fresh water because their bodies need salt.. The only shark that is known to be able to switch from sea water to fresh water is the bull shark.. Bull sharks can survive in both saltwater and freshwater , and have been known to frequent the lake.. ... Bull sharks can survive in freshwater by regulating the amount of salt in their bodies.. Types of Freshwater Sharks: The sharks of rivers and lakes. The Ganges Shark (Glyphis Gangeticus) is often mistaken for the more dangerous Bull Shark.. Salmon sharks are large sharks that live in the north Pacific where they hunt their favorite prey – salmon.. Whilst it is theoretically possible for bull sharks to live purely in fresh water, experiments conducted on bull sharks found that they died within four years .. Freshwater sharks are sharks able to live in freshwater lakes and rivers, including: ... the bull shark , Carcharhinus leucas, which can swim between salt and fresh water, and are found in tropical rivers around the world.. The average shark can't live outside a saltwater environment any more than you could live in outer space , but there are quite a few species of sharks that swim in freshwater for short periods of time, and some that have nearly completely adapted to a non-salty lifestyle.


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