Researchers are unlocking some of the mysteries of sperm whale sounds, and it's all thanks to an underwater camera set up to catch bait fish burglars. Sperm whales have been caught on camera stealing from a longline off the coast of Alaska.

This reveals more than their savviness to gather good, it exposes special clicks these make as they approach the bait.

With this recording from a depth of 328 feet, researchers can link the size of a whale's head to the volume of the clicking sound.

The roots of this unique study began in Alaska after sperm whales developed the ability to steal black cod off longlines. That's when frustrated fishermen attached a camera to the line.

"Fishermen can find a way maybe to change they way they are fishing to avoid sperm whales getting all of their fish," Scripps Institution of Oceanography grad student Delphine Mathias said.

Scripps researchers say the video may help fishermen reduce sperm whale encounters and entanglement with their gear.