About TOPP

Tagging of Pacific Predators began in 2000 as one of 17 projects of the Census of Marine Life, an ambitious 10-year, 80-nation endeavor to assess and explain the diversity and abundance of life in the oceans, and where that life has lived, is living, and will live.

Several dozen TOPP researchers from eight countries began venturing into offshore waters, remote islands, and along rugged coastlines to attach satellite tags to 22 different species of top predators that roam the Pacific Ocean. As of 2007, they have tagged more than 2,000 animals, including elephant seals, white sharks, leatherback turtles, squid, albatross and sooty shearwaters.

As these animals began sending back data via Argos, a polar-orbiting satellite, they opened the door to a world we'd never seen before: a picture of their migration routes and their ecosystem...through their eyes. We humans were finally able to witness their journeys through, what is to our human perspective, featureless blue waters. We’ve learned that many of these animals use those routes as regularly as college students migrating to Florida for spring break. Marrying other satellite imagery to the animals' tracks, we’ve started to identify the ocean equivalent of desert oases or the watering holes of African savannahs, where the animals gather to feed and to breed. A big question is: how do these ocean animals know where to find these “hot spots” that continuously form and swirl through the seas?

These voyagers are giving us better data to protect the endangered species among them, such as leatherback turtles, black-footed albatross and blue whales. They're also providing information to better manage fisheries -- such as bluefin tuna, yellowfin tuna, and swordfish -- that risk collapse or threaten the survival of other species caught in nets and long-lines.

Who is TOPP?

Marine biologists, oceanographers, engineers, computer programmers, journalists, graphic designers, educators and others, like you, who are interested in sustainable oceans. NOAA’s Pacific Fisheries Ecosystems Lab, Stanford’s Hopkins Marine Lab, and University of California, Santa Cruz’s Long Marine Laboratory manage the program.

TOPP receives funding from the Alfred P. Sloan Foundation, the David and Lucile Packard Foundation, the Gordon and Betty Moore Foundation, NOAA's Office of Exploration, the California Sea Grant program, the Office of Naval Research, and the National Oceanographic Partnership Program.

The Tags

People have been tagging fish for more than 125 years to track their migrations -- the first fish tagged were Atlantic salmon in 1873, in Maine’s Penobscot River. After sonar (SOund Navigation And Ranging technology that uses sound to detect objects underwater) was perfected in the 1940s and 1950s, researchers began using acoustic tags. In the 1970s and 80s, data loggers were developed. These tags measured time, depth, internal temperature, swim speed and heart rate. Researchers had to catch, tag, and recatch an animal to retrieve the tag and its data. The big breakthrough came in the 1990s, when advances in computer and satellite technology increased the amount of data a tag could hold (some tags record every four seconds) and made data accessible remotely.


We use:

Archival tags

They’re small, powerful, and can last up to 10 years. Researchers surgically implant them into the bellies of tuna, where the tags record – as often as every few seconds -- pressure (for depth of dives), ambient light (to estimate location), internal and external body temperature, and, in some cases, speed of travel. The tags are small and light enough to be attached to the outside of an animal, such as the tail feathers of red-footed boobies.

Their drawback: they have to be retrieved. So, they’re useful for fish that are likely to be caught as popular seafood, such as bluefin or yellowfin tuna. And for animals that return to rookeries or nesting beaches, such as boobies and leatherback turtles.

Pop-up archival tags (PAT)

These larger tags are designed to release from an animal at a pre-set time – such as 30, 60, or 90 days after the tag’s attached – and float to the surface. A tag then sends samples of its data to the polar-orbiting Argos satellite for about two weeks, the life of its battery. After the battery dies, the data survives so that if the tag is found, researchers can download the entire data set.


This tag is useful for animals that don’t spend a lot of time at the surface, and aren’t caught often.

It collects information about pressure (for depth of dives), ambient light (to estimate location), internal and external body temperature.

We've tagged quite a few white sharks with this tag. White shark researcher Sal Jorgenson holds a pop-up tag in the photo above. That tag was attached to this white shark. He attached the tag by inserting a small surgical titanium anchor into the shark. (Do sharks notice when they're being tagged? Some flinch. Others show no reaction, says Sal.) On elephant seals, the tag is glued to the fur. Connecting the tag to the anchor is a thin line that loops around a metal pin at the base of the tag. This metal pin is connected to a battery. A clock in the tag turns the battery on at a preprogrammed time. When the battery turns on, the attachment pin dissolves. The tag floats to the surface and starts transmitting data to one of the Argos satellites.

SPOT – Smart Position or Temperature Transmitting Tag

This is an ideal tag for air-breathing marine animals (seals, whales and sea turtles) and animals that often swim close to the surface (salmon sharks, blue sharks and makos). When the antenna breaks the surface, it sends data to a satellite. The data includes pressure, speed, and water temperature. Location is estimated by calculating the Doppler shift in the transmission signal in successive transmissions. When the animal goes beneath the surface, a saltwater switch turns off the tag. The tag, made by Wildlife Computers, lasts about two years.

SRDL – Satellite Relay Data Logger

These tags compress data so that more information can be transmitted through the Argos satellite. These can be outfitted with CTD tags that record salinity, temperature and depth, data that oceanographers need to identify ocean currents and water . Elephant seals, sea lions and leatherback sea turtles wear these tags.