Tidepools offer more than visual beauty—they also host a symphony of sounds. By using hydrophones to capture these underwater noises, we can hear the hidden rhythms of creatures like the zebra blenny, periwinkle snail, rock-boring sea urchin, snapping shrimp, and rock crabs. While this experience described here is found in Maui’s tidepools, it can be applied to other coastal areas with similar ecosystems.
The Role of Hydrophones in Exploring Tidepools
Hydrophones allow us to hear sounds beneath the water’s surface, revealing a world that would otherwise go unnoticed. These underwater microphones amplify the subtle noises made by marine life, giving us a richer understanding of their behaviors and interactions. Hydrophones open up a new dimension to exploring tidepools
Audio of CRT-70P hydrophone deployed in tide pools, Maui 2025
Zebra Blenny
Zebra blennies, small fish known for their striped appearance, are a common sight in tidepools. There is no scientific documentation of the zebra blenny producing acoustic sounds.
Periwinkle Snails: The Rasping Rhythm
Periwinkle snails, found crawling along rocky surfaces, add a different texture to the sound environment. It is thought that you can hear the rasping noise they make while feeding, as they scrape algae off rocks using their radula—a specialized feeding organ. This soft, scraping sound may be detectable through a hydrophone, creating a gentle, rhythmic background that blends with other sounds in the tidepool.
Rock-Boring Sea Urchins: The Grinding Architects
Rock-boring sea urchins are capable of drilling into solid rock to create homes for themselves. Using a hydrophone, you can hear the grinding sound as the urchins use their jaws to drill into the rock surface. This creates a steady, mechanical hum, contrasting with the livelier sounds of other tidepool creatures.
Rock Crabs: The Subtle Movements
Rock crabs often make soft rustling or tapping noises as they move between rocks or scuttle along the seabed. Their activities can produce a variety of gentle, rhythmic sounds.
A Deeper Connection to Nature
Using a hydrophone while exploring tidepools enriches the experience for nature enthusiasts by offering a deeper, more intimate connection to the creatures that inhabit these ecosystems. It opens up a new way to learn about their behaviors and interactions, helping us better understand and appreciate the diverse species that share the world with us. These sounds create a rich auditory picture of life beneath the waves, deepening our connection to the creatures of the tidepools. Listening to these sounds helps us appreciate the delicate balance of life in these vibrant, often-overlooked ecosystems.
