Beluga Echolocation & Marine Acoustic Ecology

How does a whale 'see' with sound?

1. Phonic Lips (Monkey Muzzle): High in the nasal passages below the blowhole, air pushed across membranes produces rapid high-frequency click bursts (up to 120,000 Hz!).

2. The Melon: The bulbous forehead is packed with acoustic lipids that focus the sound beam forward like a flashlight lens.

3. Lower Jaw Reception: Returning echoes hit the lower jawbone, traveling through special fat channels directly to the middle ear and brain.

Students stand in a large circle forming the 'Cook Inlet shoreline'. One blindfolded student in the center plays the BELUGA, and 2–3 students play SALMON.

The Beluga calls out 'CLICK!' (or shakes a rattle). Any salmon directly in front must immediately reply 'ECHO!'.

Using stereophonic hearing alone, the blindfolded Beluga must tag the salmon before the salmon quietly escape to the circle edge!

In Round 2, the teacher introduces noise pollution: half the circle makes loud continuous engine rumble sounds (imitating shipping lanes into the Port of Alaska).

Students discover that acoustic masking drowns out the faint 'ECHO!' signals—the Beluga becomes completely disoriented and starves, demonstrating the real-world impact of industrial noise on endangered whales.

TTCD and scientific partners deploy underwater hydrophones (microphones) moored to the seabed off Tyonek to record beluga echolocation clicks 24/7.

Data guides seasonal vessel speed restrictions and noisy construction bans during the critical May–June eulachon run and July–August king and coho salmon runs.

Students share how disorienting it felt to lose acoustic cues when human noise was introduced.

We reflect on Tebughna oral histories where belugas and people lived in close harmony along the beach, and brainstorm ways to keep coastal waters quiet.