Air Date: Week of August 25, 2000

The world beneath the sea is filled with mysterious sounds - from grunts and crackles and croaks to bleeping ship sonar and the roar of jet skis. "Sounds of the Sea," an exhibit at the New England Aquarium in Boston, Massachusetts, uncovers some of the sound-rich secrets of the underwater world. Living On Earth’s Eileen Bolinsky joined Aquarium Director of Education Billy Spitzer for a tour.

Transcript

CURWOOD: Snap, crackle, pop. No, this isn't the sound of your morning cereal. It's just some of what you might hear if you put your ear to the underwater world. Mating calls, territorial grunts, thunderstorms, and earthquakes make the ocean a pretty noisy place before one even considers boats and other human activities. So scientists are now studying how sea creatures use and respond to sound. Some of what they've learned so far can be heard in Sounds of the Sea, a display recently opened at the New England Aquarium in Boston. Living on Earth's Eileen Bolinsky toured the exhibit with Aquarium Director of Education Billy Spitzer.

(Thunderous sounds and gravelly calls)

SPITZER: We call this first part our sound tunnel, and it allows you to follow the migratory journey of a humpback whale from Greenland down through the north and mid-Atlantic down to the Caribbean. And on the way to hear the sounds that whale would hear on that kind of migration.

(Whistling and songs)

SPITZER: Some of the most intriguing sounds for me have been the sounds that we've gotten from the Arctic regions, because they're really otherworldly. For example, the sounds of ice creaking and groaning as it cracks and pieces rub together, and then some of the sounds, for example, of bearded seals, which are these very eerie, trilling calls that really sound like they're from another planet.

(Trills descending)

SPITZER: The sounds that we've used in the exhibit have all been collected by research scientists whose job it is to study underwater sound. And they've been all collected using underwater microphones called hydrophones.

(More thunderous sounds)

SPITZER: Some of the most intriguing whale sounds, for example, the finback whale and the blue whale, have these very low frequency calls that you really feel more than you hear.

(More thunderous calls)

SPITZER: I feel like when you're listening to those sounds, it gives you some impression of how resonant the ocean is.

(Low call)

SPITZER: Many people believe, in fact, that whales may be communicating across entire ocean basins, for example, one side of the Atlantic to another.

(Low call continues; waves)

SPITZER: In the mid-Atlantic, after kind of taking a deep breath, going underwater with a whale, get to hear some of the sounds of some other marine mammals like dolphins and so on.

(Dolphin whistles, followed by thunderous call)

SPITZER: And hearing some of the sounds, as well, of ship noise, for example, the sound of a big container ship, which is really pretty dramatic. It's got a kind of a nice beat to it. But you can hear it really overpower some of the sounds of the animals.

(Loud resonance)

SPITZER: One of the things that's hard is to directly measure the impact of noise in the ocean. One of the reasons it's tough is that you have to find a way to see that impact on animals, and some experiments have been done, for example, where people have tracked marine mammals and found that they either avoided or didn't avoid a particular sound source in terms of their swimming behavior. But in a lot of cases we can only speculate. We don't know exactly how whales are using their calls to communicate. We don't know whether the noise we're adding to the ocean, for example, is making it harder for them to hear each other, and perhaps making it harder for them to find each other and find mates. But I think, particularly in the example of coastal areas, where there are a lot of small engines around, you know, jet skis and slow motor boats and so on, it's something we ought to be paying attention to. And I think if there are nonessential sources of noise that we can eliminate, that's something we certainly should be thinking about.

(Whale calls and waves)

SPITZER: And sound is so important as a tool in the ocean, because light doesn't travel very far in the ocean. Radio waves don't travel very far. It's only sound that allows you to probe very far in the ocean. And that's one of the reasons why so many scientists are using it.

(Bubbling)

CURWOOD: Since we first broadcast this story last year, the Sounds of the Sea exhibit has moved on to the Norwalk Aquarium in Norwalk, Connecticut.