Echolocation: Using Sound for Sight
Echolocation is the ability to orient by transmitting sound and receiving echoes from objects in the environment. As a result of a Marco-Polo type activity and subsequent lesson, students learn basic concepts of echolocation. They use these concepts to understand how dolphins use echolocation to locate prey, escape predators, navigate their environment, such as avoiding gillnets set by commercial fishing vessels. Students also learn that dolphin sounds are vibrations created by vocal organs, and that sound is a type of wave or signal that carries energy and information especially in the dolphin's case. Students learn that a dolphin's sense of hearing is highly enhanced and better than that of human hearing. Students are also introduced to the concept of bycatch. They learn what happens to animals who are unintentionally caught while fishing for other species.
Three enthusiastic dolphins at Sea World!Copyright Paradise Dive Club
After learning how echolocation works, students discuss how net designs can be made easier for dolphins to "see" via echolocation and thus help them avoid getting tangled in nets. Engineers are also inspired by concepts observed in nature, such as echolocation; for instance, sonar on submarines is simply a type of echolocation.
After completing this lesson, students should be able to:
- Define "echolocation" and list three benefits for the dolphin species.
- Explain that dolphins have a better sense of hearing than humans
- Define all lesson key words and be able to make statements in a discussion that relate the keywords to dolphins and their behaviors in the ecosystem.
- Explain why dolphins need their echolocation abilities especially when hunting deep below the ocean's surface.
- Describe how dolphins are mammals and not fish, and give at least one reason why.
- Define bycatch and explain what happens to the animals affected.
- Explain how dolphins can use echolocation to avoid nets.
- Discuss how nets can be better engineered to protect dolphins from bycatch by taking advantage of echolocation.