Smart Position and Temperature (SPOT) Tags
SPOT Tags are one of the most advanced technology tags used by researchers. Like the other types of tags, it records a variety of measurements, such as temperature, salinity, and depth. However, powered by a very powerful transmitter, SPOT Tags regularly send their recorded data to satellites. These tags are primarily designed for use on animals that are commonly found at the ocean's surface, where regular broadcast to a satellite is possible. Therefore, they are suited for use on dolphins, turtles, seals, and any other animal that must spend at least some regular time at the ocean surface. Recently, these tags have been successfully placed on the dorsal fin of sharks that swim at the surface. These tags are fairly expensive and require large batteries to power them. To save battery power, some tags are fitted with a switch that turns them off when they become submerged under water, turning back on when the tag comes to the surface where it transmits again.
Click on the link below to see what Census projects use this technology: