Gallery 5.2: Scientific Tag Types

Conventional dart tags are composed of a composite plastic barbed head with a polyvinyl plastic streamer/shaft. Different colors can indicate the presence of additional, internal tags. (Photo: SPC)

Plastic "spaghetti" tag. (Photo:

Example of sonic tags (left) and of a sonic receiver on a FAD (right). Sonic tags are miniature radio transmitting devices that are surgically implanted inside the tuna. Since sonic tags are not visible externally, a conventional tag of a certain color will be visible on the outside of the fish. (Photo: SPC)

Smart Position or Temperature Transmitting (SPOT) tags are attached to a fish’s dorsal fin; the tag sends a signal to a satellite every time the fish surfaces. (Photo: SPC)

Rototags are a two-piece, plastic cattle ear tag, which is inserted through the first dorsal fin. (Photo: MarBEE, UCD)

Archival tags are miniature computerized data recorders that are surgically implanted into the tuna’s body (antenna, red arrow). (Photo: SPC)

Satellite tags record the same information as archival tags but they do not need to be recovered. They are fixed on the back of the fish and after a predetermined time, they will detach from the fish, float to the surface, and transmit the recorded information to a satellite. (Photo: SPC)