U.S. flag An official website of the United States government.

dot gov icon Official websites use .gov

A .gov website belongs to an official government organization in the United States.

https icon Secure websites use HTTPS

A small lock or https:// means you’ve safely connected to a .gov website. Share sensitive information only on official, secure websites.

Ocean as a Lab: Population Surveys



My name is John Hildenbrand, and I study the acoustics of whales and dolphins. I found that by monitoring the sound, it’s a very efficient was of finding where the animals are and then also making some sort of relative assessment of how many animals there are. When we track the number of calls in each area, it helps us to estimate the number of animals that are present. We do this because we want to conserve these populations. So we’re standing outside on the FLIP. FLIP is a unique vessel. There are a series of ballast tanks that can be flooded, that make it rotate or flip up into the vertical position. There are 90 meters of FLIP beneath the water surface, another 20 meters of FLIP from the waterline to the bow, which is now pointing straight up in the air, and then 8 meters above that is a platform for observations of whales and dolphins. The big advantage of FLIP is that it creates a stable platform in the middle of the deep ocean. We can sit on FLIP, and it almost feels like land. So, for instance, we have the visual observers who are up at the top of the crow’s nest and making observations of marine mammals with binoculars, and if we were on a ship putting them at that same height, they’d be going through tremendous swings. So that’s the real strength of FLIP, is that you can do precision measurements that are not possible on a conventional ship. So we’re standing outside on the laboratory deck of the FLIP. And we’re in the vertical; FLIP is standing upright. So this is our floor, but in the horizontal, our floor would be right here; we would be standing up like this. Here, I’m standing in the vertical in the main lab, and the stairs that we would use to come in, in the horizontal, looks totally bizarre. They’re up on the ceiling. Here’s the door that works in the vertical. And here’s the door that works in the horizontal. Okay, we’ve got a sighting, and we’re excited about it. This screen is called a Spectrogram and it’s a way that we can visualize the sounds of marine mammals. Fin whales make little pulses of sound, and I can see right here, there’s kind of a blotch of energy. Fin whales use these pulses of sound to communicate between animals. There’s a worldwide moratorium on commercial whaling that’s still in effect today. But I find that most of the stocks of whales that were commercially whaled are still at low numbers. The populations have not recovered above about the 50% level. And I think it’s important to have a baseline for all the oceans of the world. We need to knowhow are they, so that we can detect when things are changing, and I think sound is a really efficient way of doing that.