Sharks are the most important predators of bottlenose dolphins along the west coast of Florida.
But sharks and dolphins often tolerate one another. They may feed on the same school of fish!
About one-third of the Sarasota adult dolphins bear shark-bite scars. So, sharks are dangerous to dolphins.
Sharks attack dolphins
The primary shark predators of bottlenose dolphins are the bull shark, tiger shark, dusky shark and great white shark.
Shark bite scars on dolphins indicate that sharks typically attempt to ambush dolphins from behind and below.
Some researchers think that shark attacks may not even be an attempt to eat a dolphin. Instead, in some cases, a shark may be attacking to defending a territory. More research is needed to test these hypotheses.
Dolphins interact with sharks
Bottlenose dolphins are also known to attack sharks by butting them or by hitting them with their tail flukes. This behavior, however, is only observed occasionally.
At other times, dolphins flee from nearby sharks. This would be very adaptive to protect calves.
Sometimes, however, dolphins and sharks swim nearby without interacting. Perhaps you have seen this on nature programs on TV. Sharks and dolphin may feed on the same school of fish.
Trained dolphin attacks shark
The SDRP’s first study in Sarasota was not with dolphins in the wild, but it involved training a temporary captive dolphin, named Simo, to repel sharks. Simo easily learned to head-butt nurse sharks, lemon sharks, and sandbar sharks on command.
But all the training broke down when a bull shark was introduced into the pool. Bull sharks are aggressive and known to eat dolphins.
Apparently Simo recognized immediately that this shark was unlike the other species. The bull shark was a threat not to be messed with.
Note: Simo was quickly separated from the bull shark, so he was not harmed.
A few weeks later Simo was released back into the Gulf of Mexico, after a year in residence at Mote Marine Laboratory.
Simo made two great leaps into the air and then swam away, never to be seen again.
Relevant SDRP publications
Irvine, B., R.S. Wells and P.W. Gilbert. 1973. Conditioning an Atlantic bottlenose dolphin, Tursiops truncatus, to repel various species of sharks. J. Mammal. 54:503-505.
Pringle, L. and R.S. Wells. 2002. Dolphin Man: Exploring the World of Dolphins. Honesdale, PA: Boyds Mills Press. 42 pp.
All photos © Sarasota Dolphin Research Program under NMFS permit #522-1785