

This makes it possible to retrieve data without having to recapture the animal. Just like other archival tags, these continuously record depth, temperature, and position, but then release from the animal at a pre-set date, floating to the ocean surface to transmit their data to satellites. Scientists with The Center for Sportfish Science and Conservation at the Harte Research Institute for Gulf of Mexico Studies, Texas A&M University Corpus Christi, are tagging large sharks along the Texas coast with pop-up archival transmitting (PAT) tags. Sharks function as top predators, and their abundance and distribution can affect entire ecosystems. Ultimately, the data could reveal where the whales feed and whether there are threats along their route to or in their feeding grounds. So far, the tags have shown that two of the whales remained in the bay where they were tagged, one swam into deep waters of the South Atlantic, another spent time over the continental shelf, and another moved into deep offshore waters then returned to the continental shelf break.

The tags transmit geographic position and other data to a satellite multiple times a day when the whales surface. In an effort to figure out why, scientists affixed satellite tags to five whales-no easy task-in breeding areas off the coast of Argentina. However, in a span of 8 years, more than 400 southern right whale calves have died. Unlike those of its endangered cousins the North Atlantic and North Pacific right whales, the southern right whale population rebounded after centuries of commercial whaling. Here are 10 animals scientists have been tagging, the kind of tags they used, and what they learned as a result. Those who study wildlife often mark individual animals in order to track their movements and mortality, using physical marks such as ear notches, numbered metal tags affixed to an ear or flipper or, more recently, high-tech tags capable of recording a variety of data and even transmitting them to satellites. Scientists use a variety of tools to collect data in the field.
