We're on our way to finding out a lot more about what goes on in that secretive world under the sea. A Census of Marine Life project called Tagging of Pacific Pelagics, or TOPP, has been sticking marine animals with electronic tags that transmit data about their habits and habitats to researchers by satellite.

The project, headed by Daniel Costa of the University of California, Santa Cruz and Barbara Block of Stanford University, records information about animals' locations, speeds, depth and duration of dives, and the temperature and salinity of seawater at various depths.

Privacy issues aside, sending animals out to infiltrate their own kind has brought back some valuable information. TOPP tagging showed that white sharks, once thought to stick around coastal areas, actually travel between locations as far apart as California and Hawaii, and Africa and Australia.

According to the project's website:

Exploring the evolutionary roots of shark habitat use by tracking their journeys has important practical application. Sharks are highly susceptible to over-fishing, and developing good models of their behavior will be critical for management and conservation efforts. Half a century after Cousteau, we may soon be able to "tell what a shark is going to do," by learning where it goes.

The famously reliable elephant seals, long used in tagging experiments, have been helpful to the TOPP team as well. For instance, following the pinnepeds' food-finding expeditions has produced information on the effects of El Nino on the ocean's depths. And TOPP tags are on the way to solving some of the major squid mysteries: where these creatures spawn, where they hunt, and where they hide.

As Kim Philby said, "To betray, you must first belong."