Off Antarctica, massive amounts of dense, salty water sink rapidly to the bottom of the ocean. This process is like a pumping heart because it drives major ocean currents that carry heat around the globe, affecting the climate.


The harsh conditions of the Antarctic make it nearly impossible for humans to study this heart of the ocean circulation system. But Weddell and southern elephant seals make excellent data collectors.

Costa: “They readily go in and around the ice in areas where we currently lack the technology to put buoys or floats or other methods of collecting oceanographic data.”

That’s Dan Costa of the University of California at Santa Cruz. Tags that measure ocean temperature and salinity are glued to the seals’ fur. As the seals dive deep in the water, they collect invaluable data that the tags transmit via satellite.

Costa: “Right now the majority of the data coming from the southern ocean are coming from animals.”

For the last decade, the seals have been collecting vital information about ocean circulation, providing a baseline that will inform future climate change models.

Reporting credit: ChavoBart Digital Media.
Photo: Female elephant seal carrying tags that will monitor its location, swim speed, and depth and duration of dives, as well as the temperature and salinity of the seawater and how that changes with depth. (Photo by Dan Costa) (Source: University of Santa Cruz)

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A regular contributor to Yale Climate Connections since 2012, David Appell, Ph.D., is a freelance writer living in Salem, Oregon, specializing in the physical sciences, technology, and the environment. His...