Experts in underwater sound tune in to the song of the whale

Aboard IFAW’s commissioned research vessel Song of the Whale, researchers use bioacoustics—the sounds of animals—to detect the presence of North Atlantic right whales. This helps inform researchers of the whales’ whereabouts and behaviour, which in turn helps us protect them from threats like vessel strikes and entanglements in fishing gear. Because the North Atlantic right whale is critically endangered, tracking and monitoring them is imperative for their survival as a species.

Transcript

Dr. Oliver (Olly) Boisseau: The right whales are now critically endangered. So, there’s fewer than 340 animals left. None of us really want to be on watch when this species goes extinct, but currently it’s not looking great. But our work with IFAW is aimed to come up with a solution to protect the future of the species.

Text: In January 2023, IFAW commissioned the research vessel Song of the Whale to sail the US east coast to study North Atlantic right whales.

Richard McLanaghan: Our core expertise is in using bioacoustics, or the sounds that marine mammals make. We spent a lot of time developing acoustic systems for detecting vocalisations or calls the right whales are making for better informing about where the whales are at any given time, so mitigation measures can be put in place. To hear those sounds, we use hydrophones, which are very sensitive underwater microphones.

Olly: We’re about to deploy the hydrophone, and this is a 400-meter cable that we can tow behind Song of the Whale. We have an oil-filled tube. And this contains an array with three microphones inside it. And then we have a pre-amplifier—so, this just boosts the signal, because we‘ve got to pass this signal all the way up to the vessel.

The computers on board are going to be doing some analysis for us and listening out for right whales. But it’s good to listen at least several times an hour just to check there’s nothing the computers are missing—because, actually, the human brain is an even more powerful supercomputer. So, sometimes the human ear is actually better than a computer ear for detecting quite subtle signals in the water column.

There are different types of vocalisations that we might expect to hear. One of the key sounds we are listening out for is called an “up call.” So, that’s quite a low frequency sound, and to me, it sounds a bit like a cow mooing. It sounds like a “moo, moo, moo.”

Richard: This year, we are using some different hydrophones that we haven’t used before, so it’s quite exciting when we are trying a new technique and you see it working. And hopefully, we’ll be able to feed a little bit more information into the puzzle. 

The right whale is critically endangered. We need to understand everything we can about how they live their lives to be able to better protect them.