Blue whales are an amazing species. They're the largest animals to have ever lived bigger than large dinosaurs. Unfortunately, they were hunted to near extinction in the 20th century, but with the end of commercial whaling in the 1980s, their populations have begun to recover worldwide. However, they still face a variety of threats from human activities. 

Blue whales live far offshore, and we know relatively little about them. They are migratory and on these migration routes, they are susceptible to threats such as crossing shipping lanes or ocean noise. And so it's imperative that we study them to help better protect them. 

Hello, my name is Bob Dziak. I'm a research oceanographer with NOAA's Pacific Marine Environmental Laboratory in Newport, Oregon. I specialize in ocean acoustics, underwater sound.

Underwater sound is the only way really to study marine animals in marine ecosystems because light doesn't penetrate very deep into the ocean. And you can't see things, but you certainly can hear things.

My name is Angie Sremba. I'm a conservation geneticist. I study the DNA of endangered species.

So we're looking to simultaneously collect eDNA samples, as well as acoustic records using underwater hydrophones to study blue whales.

Blue whales use sound to navigate, communicate, explore their environment. So the sound is a really critical component of their lives, and we use that to understand them and understand their role in the marine ecosystems. 
They can produce a really loud, underwater sound. It's also very low frequency. So if you and I were underwater and listening to it, we wouldn't necessarily hear the calls of blue whales because they're so low. But you might be able to feel it.

We like to think of our hydrophone technology we're deploying as a smart buoy. It's a surface buoy with a hydrophone that extends under the sea surface to record blue whale calls. But it has a internal microprocessor with a built-in blue whale call detector. Kind of a machine learning, you know, an artificial intelligence buoy. And then it'll let us know then not only that it detected a blue whale call, but also the position of the buoy and then transmit that information back to us on shore and from that, we can then triangulate the location of the animals.

When we sight the blue whale we'll see their spout on the surface of the water, and we'll be able to travel to the whale. And we can collect DNA from a biopsy sample or tissue sample. However, this often can be difficult to collect. So in this study, we're using a different method.

We are looking at eDNA or environmental DNA. And so by collecting water through which a whale passes when it comes to service to breathe, we can collect genetic material of the whale at the surface. And this will allow us to correlate our results from the eDNA collection with the recordings of the whale vocalizations within the acoustic hydrophone array. 

The methods we are using for eDNA collection, as well as the interpretation of these results from our eDNA, will allow us to improve our ability to track highly migratory species, such as blue whales in the open ocean environment. I'm hoping to learn that we can recognize the calls of blue whales, their unique signatures in a really robust way, really understand them, see their call, see their distribution through time and how they change.

These two different technologies are both non-invasive as well as cutting edge, and we are using these to study this blue whale population and hopefully use this technology to better understand blue populations around the world. We have to make sure that these apex predators have a healthy environment and continue to thrive.