Are sharks attracted to movement or sound when near swimmers?

Shark Attraction to Movement

Sharks are drawn to movement due to their exceptional electroreception and vision. A study by the Woods Hole Oceanographic Institution found that sharks can detect the electrical signals produced by a swimming person’s heart rate and muscle contractions, which can be as far as 1 mile away. To minimize shark attraction, swimmers should avoid sudden movements and try to swim calmly at a slower pace.

Shark Attraction to Blood in the Water

Blood in the water is another significant attractant for sharks. When a person is injured, bleeding can occur, and sharks can detect the presence of blood through their sensitive sense of smell, which is located on their dorsal fins. To prevent this attraction, it’s essential to treat any wounds promptly and prevent bleeding. In a survival situation, applying a tourniquet or using a bandage can help minimize blood loss.

Signaling for Rescue in Shark-Infested Waters

If a swimmer finds themselves in shark-infested waters and needs to signal for rescue, they should use a signaling device like a mirror, whistle, or flares. However, in areas known to be frequented by sharks, it’s crucial to use caution when signaling, as loud noises can attract more sharks. Instead, use a visual signal like a brightly colored object or a smoke signal during the day, which is less likely to attract sharks.