This is from a Radio Program, so you listen to it instead of getting your eyes tired of all this reading. Check Earth & Sky for the links.
I will just quote one passage from the interview to "Randy Kochevar, a scientist with California's Monterey Bay Aquarium" where he is asked about the different types of tags used to track animals and in particular GPS Tags:
"[...] we know where the animal is in your real time, we can check every day and learn its position. And other tags that use a different satellite system, but can still estimate the position on the globe are also being used even with some marine animals, animals that live under water but that spend enough time at the surface so that the tag can* actually talk to the satellites, and we can actually get a good solid location on that animal."* Truncated in the original
Monterey Aquarium is using Argos satellites, which offers "Geo-positioning services for North America" to track the location of the marine life.