Bull Shark (Carcharhinus leucas)

SharkCoastalEuryhaline

Overview

The bull shark (Carcharhinus leucas) is a stocky, blunt-snouted shark of warm coastal waters worldwide. It is heavy-bodied for its length, with small eyes and a broad head — the build that gives it its name.

What sets the bull shark apart is its tolerance of fresh water. Most sharks are confined to the sea, but the bull shark can regulate its internal salt balance well enough to move far up rivers and into lakes, and it has been recorded a very long way inland in rivers such as the Mississippi and the Amazon.

It is a large predator that frequents exactly the shallow, murky, nearshore waters people use, and this profile is educational only: it gives no guidance on encountering, deterring or handling sharks.

Habitat & Range

Bull sharks live in warm coastal seas around the world, favouring shallow water less than about 30 metres deep, along with estuaries, river mouths, lagoons and — distinctively — fresh water well upstream. Populations occur in tropical and subtropical Atlantic, Pacific and Indian Ocean coasts, and the species is well known from rivers and lake systems connected to the sea.

Diet

Bull sharks eat mainly bony fish and other sharks and rays, along with turtles, birds, dolphins, crustaceans and carrion. They hunt largely in turbid nearshore and estuarine water where visibility is poor, relying on senses other than sight, and are opportunistic in what they take.

Behavior

Bull sharks are generally solitary hunters, often active in shallow, murky water. Their osmoregulation — controlled by the kidneys, gills, and the rectal gland that sharks use to excrete salt — is what permits movement between sea water and fresh water. Rivers and estuaries also serve as nursery areas, where young sharks grow up with fewer large predators around.

Human Interaction & Conservation

Because bull sharks share shallow coastal and estuarine water with people, they are among the shark species most frequently associated with incidents, though such incidents are rare relative to human water use. They are also taken in commercial and artisanal fisheries and are affected by coastal development and degradation of the estuarine nurseries their young depend on. This profile gives no safety, deterrence, fishing or handling guidance; follow local authorities and posted advice. Verify current status at the IUCN Red List.