The Great Marlin Race

The Great Marlin Race relies upon "Pop up Satellite Archival Tags," made by Wildlife Computers.  These tags are attached externally to the fish by a heavy monofilament leader, which loops around a special pin at the bottom of the tag. Once the fish is tagged, the tag records depth, temperature and light - which is used to calculate the fish's location. At a pre-programmed date, the pin at the bottom of the tag corrodes away, setting the tag free from the fish. The bulbous float at the top of the tag carries it to the surface, allowing the antenna to begin relaying data via the Argos satellite system back to the laboratory. As the data arrive at the lab, scientists are able to re-create the fish's journey through the ocean - creating a map of the path it took, along with a record of its diving behavior and the temperature of the water it swam through.

Pop-up Archival Satellite Tags are used to record information about a fish's location and behavior.