Shark Tags

How the Atlantic Shark Institute Uses Technology to Follow Sharks Beneath the Waves

For decades, scientists have used tagging to unlock the mysteries of shark movements, migrations, and behavior. What began with simple identification tags has evolved into sophisticated technology capable of following sharks across hundreds—and even thousands, of miles of ocean.

The Atlantic Shark Institute uses several types of tags, each designed to answer different questions about where sharks travel, how they use their environment, and how their behavior changes over time. From the long-running NMFS “M” Tag to advanced acoustic and satellite technologies, these tools provide researchers with an increasingly detailed picture of the lives of sharks in the wild.

Explore the tags below to learn how each technology works, and how the information they provide is helping scientists better understand and protect sharks.

Acoustic Tag

Lifespan: 10 years

Acoustic tags are the foundation of a growing number of research projects. These tags allow researchers with the ability to monitor the movement and behavior of a wide variety of aquatic animals via an extensive acoustic receiver array stretching from Canada to the Gulf of Mexico. Our preferred tag is the V16 with 10 years of battery life on each tag which allows us to track sharks for a decade of migrations up and down the coast.

Spot Tag

Lifespan: 5 years

This tag is perfect for sharks that may visit offshore environments where acoustic receivers might be less prevalent or logical. When at the surface, SPOT tags send out short transmissions to the Argos satellite system. These transmissions are used to calculate the location of the transmitter (shark). Data is available in near-real-time with accuracies as high as 250 meters. These tags have approximately five years of battery life on each tag.

PSAT (Pop-off Satellite Archival Tag) Tags

Lifespan: 2 years

These tags are designed to track the large-scale movements and behavior of sharks which do not spend enough time at the surface to allow the use of real-time Argos satellite (SPOT) tags. They record depth, temperature, and light-level data that are summarized for transmission and archived in onboard memory. Then on a preset date set by the ASI, the tag releases from the shark, surfaces, and uploads a summary of the archived data to Argos satellites. These tags have a battery life of approximately two years.

NMFS "M" Tag

Lifespan: No limit

This tag version and program was initiated by the NMFS in 1962 and more than 295,000 sharks of more than 50 species have been tagged using this tag. We apply this tag to a shark, record the data, and send it off to the NMFS. This tag has no technology in it, however, when someone else caches the tagged shark, and they record new data, it can be instrumental in providing critical data for researchers.