In 1983, scientists from NOAA’s Northwest Fisheries Science Center began ground-breaking cooperative work with the Bonneville Power Administration of the U.S. Department of Energy to determine the feasibility of tracking salmon through passive integrated transponders or PIT tags, embedded under the skin of the fish.
The PIT tag is an electronic tag 10mm long by 2.1 mm in diameter that contains a unique identification code. The tags use passive Radio Frequency Identification (RFID) technology and are activated when the fish passes over a detector in the river or stream. When activated, the PIT tag transmits its unique code to the sensor where the scientist can record the number and match it to the individual fish that received that specific PIT tag. This innovative study method allowed for very accurate tracking of fish populations without the use of cumbersome external tags and repeated handling of the fish.
The use of PIT tags proved so successful in fish studies that it was widely adopted for tracking and studying the migratory habits other species of wildlife including birds and mammals.
More recently, the PIT microchip tagging technology made the highly successful move from lab to household in the form of the popular pet identification system. Today, most veterinarians now offer pet owners the ability to insert a PIT tag under the skin of the animal’s neck, allowing lost animals to be quickly and painlessly identified and reunited with their owners.