How do sharks find prey using their sense of smell?

Sharks possess a highly developed sense of smell, which serves as a primary method for locating prey and guiding them toward a food source.1

Sharks utilize two nostrils to detect incredibly minute concentrations of substances in the water, such as blood, sometimes identifying one molecule of a substance in over one million molecules of water. To navigate toward the source of an odor, sharks move in a zig-zag pattern along ocean currents, using their sensitive nostrils to track the scent.21

This olfactory ability is supported by significant brain specialization; for instance, approximately 14 percent of a great white shark’s brain is dedicated to processing smell. While smell is a critical tool, it functions as part of a well-integrated sensory system that includes the lateral line system for detecting vibrations, electroreception for sensing electrical signals from prey, and acute vision.231