High Tech Tagging of White Sharks Off California Coast

December 3, 2007

The San Diego Union Tribune had a fascinating article by Gordon Smith, Copley News Service, in its November 18, 2007 edition that described how advances in technology have made it possible to gain a much better understanding of the white shark (great white shark) population off the California coast. California is one of only three places in the world where large populations of great white sharks are found. Australia and South Africa are the other two locations.

Advances in electronics, digital and materials technology have now made it possible to embed a new generation of rugged and more sophisticated electronic tags for tagging white sharks. A sophisticated microcomputer is embedded in each $3,500 battery-powered tag. The embedded computer records water depth, temperature and ambient light approximately every 15 seconds. The tags are designed to pop off the shark months later and float to the surface. Once on the surface, the tags can transmit some of their data to a polar-orbiting satellite once it gets a fix on the location of the tag.

The tags are attached near the base of the dorsal fin of the white shark by using a 10-foot tagging pole with a dart that punctures the shark’s skin. These electronic tags are in regular communication with a polar-orbiting satellite.

At the time of publication of the article, approximately 100 white sharks had been tagged by marine scientists. One of the interesting findings of the tagging study so far is that white sharks spend their early years feeding on fish along the coasts of Southern California and Baja, then move north to areas north and south of San Francisco, where as adults they prey on seals and sea lions.

Check out this well written article for a lot more information on the shark tagging program.