Swordfish may be using deep dives to navigate the open ocean

Swordfish spend much of their time hunting prey about 600 meters (1,970 feet) below the surface in the ocean twilight zone, but occasionally, they reach depths of more than 1,000 meters (3,280 feet). Now, scientists from the Woods Hole Oceanographic Institution (WHOI) are investigating what may be behind these extreme dives.