BULL SHARK
FACTS.

Top 10 bull shark facts

1. Bull sharks are one of the few sharks that can live in both saltwater and freshwater.
2. Researchers have recorded them far up major rivers, including the Amazon and the Mississippi, and in Lake Nicaragua.
3. Adult bull sharks typically reach 2 to 3 meters (7–10 ft) long — the biggest, always females, approach 3.5 meters (11 ft).
4. In southern Africa they’re known as Zambezi sharks, after the river they swim up.
5. Pups are born in estuaries and river mouths — sheltered nurseries where young sharks can grow.
6. In 2025, researchers documented the first known transoceanic crossing by a bull shark — from Mozambique, around the southern tip of Africa, to Nigeria.
7. Our tracking in Mozambique shows bull sharks living year-round in the Bazaruto Seascape.
8. Bull sharks are powerful top predators that eat fish, including other sharks, as well as rays.
9. Females return to the nursery areas where they were born when it is time to give birth.
10. Bull sharks are listed as Vulnerable on the IUCN Red List.

How big do bull sharks get?

Adult bull sharks typically measure 2 to 3.5 meters (7–11 ft) long. Their heavy, muscular build gives the species its name. Females grow larger than males. The growth studies put the maximum size for females at around 3.2 meters, although the largest individuals can grow longer. Pups are about 80 cm long when born.

They aren’t the longest sharks in the sea, but few species match their bulk. A large female bull shark is an imposing animal.

Why can bull sharks swim in freshwater?

This ability sets bull sharks apart. Almost all sharks live only in the sea because their body chemistry depends on saltwater. Bull sharks are euryhaline: their kidneys and special rectal glands can retune how much salt they keep or release. This lets them move between the sea, brackish estuaries, and freshwater.

That is why bull sharks turn up hundreds of kilometers up the Amazon and Mississippi rivers, in Lake Nicaragua, and in African rivers such as the Zambezi. The river gives the species its southern African name: the Zambezi shark. Young bull sharks often use rivers and estuaries as nurseries, where many large marine predators cannot follow.

Where do bull sharks live?

Bull sharks live in warm coastal waters around the world. They usually stay close to shore in the tropical and subtropical Atlantic, Indian, and Pacific Oceans, as well as in connected rivers and estuaries.

They were long thought to hug coastlines. Then, in 2025, researchers including MMF’s Dr Stephanie Venables documented the first recorded transoceanic movement by a bull shark. A female tagged off southeast Africa was tracked through southern Mozambique and South Africa, then turned up in a fishery off Nigeria — a journey of more than 7,000 kilometers (4,500 miles) around the southern tip of Africa and up the Atlantic coast. It is the longest movement ever recorded for the species, and it changed what we thought bull sharks could do.

Our acoustic tracking in Mozambique’s Bazaruto Seascape adds local detail. Adult bull sharks live there year-round, with core habitat along the seaward reefs. Most of that core habitat — 82% — falls inside existing marine protected areas. The sharks also use the seascape as a stop along a coastal corridor that connects aggregation sites across national borders in southeast Africa. Protecting them takes cooperation between countries, not just lines on a map.

What do bull sharks eat?

Bull sharks are apex predators that eat many kinds of bony fish, rays, and other sharks, including smaller bull sharks. They hunt mainly in shallow, often murky coastal water. Their stocky bodies and burst speed work well in this habitat. Hunting in river mouths and cloudy water is one reason they encounter people more often than most sharks do.

Are bull sharks dangerous?

Bull sharks deserve respect. Along with white and tiger sharks, they are among the species most often involved in serious bites. One reason is that they hunt in the same shallow, murky water where people swim. In Mozambique, interactions have caused deaths. They have also led to resentment and persecution of the species in some communities, making conservation more difficult.

The context matters, though. Shark bites remain extremely rare compared with the millions of people who enter the sea, and bull sharks do not seek out humans. The practical advice is simple: avoid swimming in murky water, river mouths, and estuaries at dawn and dusk, where a hunting bull shark could mistake a person for prey.

How do bull sharks reproduce?

Bull sharks give birth to live young, usually in estuaries and river mouths. Females show strong philopatry, meaning they return to the region where they were born to have their own pups. This makes nursery areas critical habitat. If an estuary disappears, so do the future generations of sharks that would have returned to it.

Why do bull sharks matter?

As top predators, bull sharks help keep coastal food webs in balance. They are listed as Vulnerable on the IUCN Red List, and pressure is rising. Fisheries assessments in Mozambique have recorded shark catches increasing by up to 220% in recent years. In some areas, bull sharks are among the most commonly landed species, making up as much as 17.3% of total shark catches.

Our bull shark research in Mozambique tracks where these sharks live, breed, and travel, providing the evidence that protected areas and cross-border management depend on.