Sharks live in all five oceans and in every zone within them: tide pools, mangrove creeks, coral lagoons, open blue water, under Arctic ice and down to about 3,700 m in the deep sea.
A handful also live in fresh water. Bull sharks run thousands of kilometres up rivers, and the river sharks of the genus Glyphis spend their lives in tidal rivers in northern Australia and New Guinea. What decides where a given species sits is temperature, depth, food and the shape of the bottom, not distance from land — and most sharks occupy a far narrower band than the group as a whole.
- Oceans with sharksAll five
- Deepest reliable recordsAbout 3,700 m
- Sharks that live in fresh waterBull sharks and the river sharks
On this page
Every ocean, and the full range within them
Sharks are present in the Atlantic, Pacific, Indian, Arctic and Southern oceans, and the vertical range they cover is more striking than the horizontal one. At the top, the epaulette shark spends its life in water under three metres deep on Australian and New Guinean reef flats, and is regularly stranded in tide pools that lose most of their oxygen overnight; it survives by shutting down parts of its brain and walking between pools on stiffened fins. At the bottom, the deepest reliable shark records sit near 3,700 m, held by the Portuguese dogfish and the cookiecutter shark.
Between those two extremes the water is not evenly occupied. Coral reefs cover well under one per cent of the sea floor and support roughly a quarter of all marine species, so reef sharks are packed into a very small area. The open ocean is the opposite: enormous, thinly populated, and crossed by species that have to cover distance to eat.
One line in the older version of this page needs correcting. Sharks were described as not territorial and as changing habitat constantly. Many species are in fact strongly site-faithful. Lemon sharks return to the nursery where they were born to give birth, and white sharks come back to the same aggregation sites in the same months year after year. Moving long distances and returning to a fixed place are not opposites.
Temperature does most of the sorting
The simplest way to divide sharks by habitat is by water temperature, and the three-way split into tropical, temperate and polar species holds up well. Tropical sharks — blacktip reef sharks, nurse sharks, most of the wobbegongs — sit in water that rarely drops below the low twenties Celsius and usually stay within a small home range. Temperate species range more widely because their water moves more.
Polar sharks are a much shorter list. The Greenland shark is the definitive case: it lives in Arctic and North Atlantic water close to freezing, has been recorded down to 2,200 m, and radiocarbon dating of eye lens tissue puts the oldest individuals at several centuries. It manages this at a pace that would be slow for a person walking. The black dogfish shares the same cold, and the full Arctic list is shorter than most people expect.
A small group cheats the boundary. The mackerel sharks — the salmon shark, the porbeagle, the great white — run counter-current heat exchangers that keep the swimming muscles, gut and brain several degrees above the surrounding water. That is why salmon sharks hunt in the sub-Arctic Pacific and white sharks work cold seal colonies that most large sharks could not use.
The habitats, from the surf line down
Estuaries and mangroves. Where a river meets the sea the water is brackish, murky and full of small prey, and it is where a great many sharks are born. Young lemon sharks spend their first years among mangrove roots, and the long-running work at Bimini has followed individual animals from birth through that nursery phase.
Sand and mud flats. The continental shelves are mostly soft bottom, which suits ambush hunters. Angel sharks lie buried with only the eyes showing and strike upwards; sawsharks work the sediment with a toothed rostrum and a pair of barbels.
Coral reefs. Reef sharks are small, abundant and highly local. Blacktip reef sharks stay above 30 m for the most part and patrol the same stretch of reef flat for years.
Open ocean. The pelagic zone is where the fast, wide-ranging species live: blue sharks, makos, oceanic whitetips and the threshers. Prey there is scattered and mobile, which selects for speed and for the ability to cross an ocean.
The deep sea. This is where most shark species actually are. Lanternsharks, catsharks, dogfishes, the frilled shark and the goblin shark all belong to water below the light. The goblin shark, incidentally, is not a common animal: it is recorded between about 40 and 1,300 m and encountered rarely enough that most specimens come from fishing bycatch.
The sharks that live in fresh water
Very few sharks can handle fresh water, because a shark's body chemistry is built around retaining urea to stay in balance with seawater. Dropping into a river means dumping that load and running the kidneys and rectal gland at a completely different rate. Two groups manage it.
The bull shark is the famous one. It moves between salt and fresh water at will, and the records are long: animals have been reported some 4,000 km up the Amazon, and one was reported caught on the Mississippi at Alton, Illinois, in 1937, more than 1,700 miles from the sea. Bull sharks also use Lake Nicaragua, reaching it through the rapids of the San Juan River rather than being trapped there, which was the earlier assumption. They still breed in salt or brackish water; the rivers are feeding and nursery habitat, not a full life cycle.
The genuine freshwater specialists are the river sharks of the genus Glyphis, and almost nobody sees them. The speartooth shark lives in the tidal rivers and estuaries of northern Australia and New Guinea in water between zero and 40 m deep, hunting catfish and prawns in visibility of a few centimetres. Adults are known from a handful of specimens. The Ganges shark is in the same position on the Indian subcontinent. Both are threatened, and both are limited to river systems that are heavily fished and heavily modified.
Depth, and the figures that get quoted wrong
The ocean averages about 3,682 m deep, not the two and a half miles the older version of this page gave, and its total volume is in the region of 1.3 billion cubic kilometres. The claim that "over 300 million cubic miles" of it counts as the pelagic zone was really a restatement of the volume of the whole ocean, which is close to 320 million cubic miles. Nearly all of the sea is open water, and nearly all of it is dark.
Individual depth records are worth keeping straight, because they show how badly the surface picture misleads. The whale shark, an animal people meet snorkelling, has been tracked to 1,928 m. Great whites have been recorded to about 1,200 m. The frilled shark is usually between 500 and 1,000 m. The cookiecutter shark commutes daily from 3,700 m to the surface and back, taking circular plugs of flesh out of tuna, dolphins and other sharks on the way.
Put together, the honest answer to where sharks live is that a swimmer sees a thin slice of it. The great majority of species are small, deep and cold-water, and they will never meet a person in the water. If you want the version organised by country rather than by habitat, that is what sharks around the world is for.
Frequently asked questions
Where do sharks live?
In all five oceans and at every depth within them, from tide pools a few centimetres deep to roughly 3,700 m down. They occupy coral reefs, sandy shelves, estuaries, kelp forests, open ocean and Arctic water under the ice. A small number also live in rivers, and bull sharks move freely between rivers and the sea.
Do any sharks live in fresh water?
Yes, but very few. Bull sharks travel thousands of kilometres up rivers and use lakes such as Lake Nicaragua, while still breeding in salt or brackish water. The river sharks of the genus Glyphis, including the speartooth shark of northern Australia and New Guinea, spend their whole lives in tidal rivers.
How deep in the ocean do sharks live?
The deepest reliable records sit near 3,700 m, held by the Portuguese dogfish and the cookiecutter shark. Most of the world's shark species are deep-water animals: lanternsharks, catsharks and dogfishes living hundreds of metres down. Even surface species go far deeper than expected, with whale sharks tracked to 1,928 m.
Are there sharks in the Arctic?
Yes, though the list is short. The Greenland shark is the best known, living in water close to freezing and recorded to 2,200 m, and the black dogfish shares the same range. Cold water slows everything down, which is part of why the Greenland shark is the longest-lived vertebrate known.
Do sharks stay in one place or migrate?
Both, and often in the same animal. Reef sharks may spend years on one stretch of reef. White sharks cross ocean basins and then return to the same aggregation site in the same month each year, and lemon sharks return to the nursery where they were born to give birth. Long movement and strong site fidelity coexist.
Which sharks live in coral reefs?
Blacktip reef, whitetip reef, grey reef and Caribbean reef sharks are the common ones, along with nurse sharks, zebra sharks and the wobbegongs on the bottom. Reefs cover a tiny fraction of the sea floor but support about a quarter of marine species, so reef sharks live at unusually high density in a very small area.
Why can't most sharks live in rivers?
Because a shark keeps its body chemistry in balance with seawater by retaining urea in its blood. In fresh water that becomes a liability, and the animal has to dump urea and run its kidneys and rectal gland at a completely different rate. Only bull sharks and the river sharks have the physiology to do it.
Where do most shark species actually live?
In deep, cold water that people never enter. The majority of the 500-plus described species are small lanternsharks, catsharks and dogfishes living on continental slopes and seamounts hundreds of metres down. The large coastal sharks that dominate public attention are a small minority of the group.
References
A small team focused on researching sharks and making marine biology easy to understand. Every page is reviewed against current species records and the SharkSider attack database, and updated when new incidents or research appear.
Published January 26, 2016 · Last updated September 23, 2026 · Filed under Cool Shark Facts.
