How do dolphins hunt?
Dolphins generally eat fish, squid, octopus, and shrimp. Dolphins don't just open their mouths and eat fish; they use different hunting techniques to catch them.
Bait ball: Dolphins often herd schools of fish into a bait ball before ploughing through it.
Too big to eat: In Costa Rica, bottlenose dolphins chase and capture fish such as yellowtail jack that are too large for them to swallow whole. Instead the dolphins grab the fish by the tail and slam it against the water's surface, breaking the fish into smaller pieces which is then easier to eat.
Flying fish: Bottlenose dolphins around Mikura Island near Tokyo feed on squid and small mackeral, but closer to the mainland, they catch flying fish called Tobiuo. To catch the flying fish, the dolphins swim upside down just below the water's surface, following the flying fish's flight pattern; when the fish plops back into the sea, the dolphin is ready to catch it. (Dudzinksi)
Crater feeding: Some fish hide under the sand. Dolphins use their powerful sonar pulses to find fish there and then dig a crater in the sand to pull out the buried fish.
Chasing fish onto mud banks and beaches: Along the muddy shores of Georgia and South Carolina, bottlenose dolphins chase mullet in a group onto the beach by creating a pressure wave that the fish try to leap from, into the waiting jaws of the dolphins. The dolphins run the risk of getting stranded there, and it takes a good deal of cooperation to make it work (see video).
In the sea near Perth Australia, a small number of female bottlenose dolphins and their calves feed in the shallows. They rely on the incoming tide to avoid permanent stranding.
Driver and barrier: Off the Florida coast, the dolphins seem to adopt two distinct roles: One acts as the 'driver' while other dolphins in the group act as 'barrier' to the fish. The driver chases the fish to the barrier and they all take turns in eating the fish. (Dudzinski).
Mud nets: Some bottlenose dolphins in the shallow waters of Florida bay use their tails to raise a wall of mud in the water, which acts like a net to squeeze the fish together until they are forced to jump straight into the mouths of the waiting dolphins (see video).
Other dolphins corrall fish with bubbles to the same effect.
Dolphins and Man: Some dolphins even cooperate with groups of fishermen to help them catch fish. See the page on cooperating with man.
Stunning fish: Dolphins can use different techniques to stun fish before eating them. They can use their powerful sonar to disorientate fish. Dolphin vocalisations can be powerful and painful and dolphins may use sound to injure the fish which they prey on.
Sometimes they may use their tail flukes to whack the surface of the water, sending shock waves that confuse the fish enough to give the dolphin a chance to catch it.