June 12, 2026 — Between June and August 2025, my fellow scientists of the Southeast Fisheries Science Center and crew of the NOAA Ship Gordon Gunter deployed a towed hydrophone array—an underwater microphone system—about 300 meters behind the ship. The goal? To detect the sounds produced by one species in particular: the endangered sperm whale in the Gulf of America.
This survey was focused on finding and studying these deep-diving giants. The scientists worked with the ship’s crew to transit through prime sperm whale habitat. Visual observers, drone operators, and acousticians were always on high alert—each using their specialized methods to detect these creatures.
Types of Sperm Whale Clicks
The towed hydrophone array picked up lots of sperm whale clicks on this 3-month trip. If the acousticians heard a whale before the visual observers spotted one, they were able to guide the ship toward the location. The array has multiple hydrophones, and measuring the tiny time differences when a click arrives at each one allowed them to pinpoint where the whale was. That’s teamwork at its finest, and it’s pretty cool, right?
But you might be wondering, what’s so special about these clicks besides helping to find the whales? Well, there’s actually a whole lot more to them!
Echolocation Clicks
Sperm whales produce different types of clicks. When they dive deep in search of food, they produce echolocation clicks to sense their environment and find their prey. They do this by listening for the echoes that bounce off of objects. The longer the echo takes to return, the farther away the object is. As they get closer to their prey, the two-way transit time for the clicks decreases, and they speed up their click rates until they’re making a rapid-fire sound called a “buzz” or a “creak.”