Reef sharks are scavengers and are not usually much of a real threat to scuba divers. They don’t usually attack unless provoked or threatened. Even cases of mistaking people for food is extremely rare and it almost always involves improper behaviour on the part of the humans.
In Belize, reef sharks have only recently begun to appear. Until recent years, nurse sharks were the only species that would be seen around the island of San Pedro. The arrival of a gang of hungry sharks was a surprise to these divers who were spearing lionfish, an invasive species that needs to be eradicated for the health of the reef. The lionfish were being carried out in a tube that was designed to store the fish in a manner that protected the divers from the dangerous stings.
These sharks arrived, likely because they smelled blood from the injured fish. They circled and followed the diver who was towing the tube on a string. He went to the bottom with the tube and then inflated a small buoy that would take the tube and fish to the surface, away from the divers. The sharks had already shown enough interest in the tube that they bit at it and tried to get at the fish inside. One end of the tube opened and fish scraps fell out. One shark came up below the diver, indicating curiosity, but this can easily turn to aggression and the divers were wise to head to the surface.
After finishing their safety stop, the divers left the water promptly and considered themselves very lucky to have gotten great footage without injury. Reef sharks are becoming more common in this area now as water temperatures and currents change. All animals in the ocean should be treated with caution and respect. Although sharks are not the dangerous killers that they are made out to be, they are not to approached without great care.