Mike aka Da Shark has been leading the bandwagon for innovation with SPOT Tags and this week it looks like there's been a breakthrough.
You'll note these well known research tags are drilled into the dorsal fins of sharks and researchers do not know what the long term effect will have on the animals - just yet.
Satellite tags are detectable over broad geographic areas and remotely relay information to satellite arrays. These tags utilize radio transmissions, requiring the tag to have contact with air to send data (hence satellite tags must be externally attached). External attachment makes satellite tags prone to damage and premature shedding. For studies of shark movements, Smart Position or Temperature Transmitting Tag (SPOT tags) are commonly attached to the dorsal fin. SPOT tags transmit a signal to the Argos satellite array whenever the dorsal fin breaks the surface of the water. These transmissions resulted in geo-location estimates with location accuracies that range from a few hundred meters to ‘somewhere on planet Earth’.
More on tags.