Huge school of fish become frantic when hammerhead shark appears

Bait balls are enormous schools of small fish, sometimes numbering in the millions. They cluster in huge schools to help avoid predators. Their shimmering scales and rapid movements make it very difficult for predators to to follow and catch them. This also allows them to have many eyes to detect a threat. They are highly sensitive to panicky movements of the other fish around them and one or two of them reacting suddenly will cause an instant chain reaction. This creates a mesmerizing effect as they dart and move like one giant organism.Show more

These scuba divers inn the Galapagos Islands are watching the bait ball swimming above them. They are an impressive sight and fascinating to observe. Their sudden and unpredictable movements were a surprise to the divers until they realized that a large hammerhead shark was cruising beneath the bait ball. In reaction to the movement of the prey fish, the hammerhead swam up and around them, causing them to rapidly turn and swim past the divers in a massive silver flash.

Hammerhead sharks are one of the top predators in the Galapagos Islands. The shark below the bait ball is swimming more quickly than the usual leisurely pace and the smaller fish know that they are in danger of being eaten. The shark is looking for stragglers that get separated from the group. By repeatedly swimming at the school and intimidating them, it will eventually cause one or two to become confused and go the wrong way. At any moment, the hammerhead might also charge the group and swim through the middle, hoping to grab a few fish in the process. This school of fish will also need to watch out for other sharks as they often hunt in groups.

Seeing the relationship in action between predator and prey in the ocean is an awe-inspiring experience.