Marine telemetry interprets into data the movements and behavior of animals as they move through oceans, coastal rivers, estuaries, and the Great Lakes. Telemetry devices, called tags, are affixed to a wide range of marine species, from tiny salmon smolts to giant 150-ton whales. Tags are attached to the outside of an animal with clips, straps, or glue, and are sometimes surgically inserted in an animal’s body.