Tracking down mystery boats on the high seas
Alex Parkin Out on the high seas, more than 200 miles from shore, seafood companies can operate with almost no oversight. These are ungoverned, international waters where it's easier for companies to get away with overfishing and abuses like modern-day slavery.
Scientists using new hacks for old technology are slowly changing that.
Two decades ago, large vessels began carrying a little box that connects to what's called the maritime Automatic Identification System (AIS). It sends out a radio signal with information about the ship, like an identifying number, and its size, course, and speed. That's supposed to help ships avoid running into each other. It also helps authorities see where vessels are when they're close to shore.
After the 9/11...