October. White shark tagging month at TOPP. It's notoriously a bad-weather month. No wonder that white shark researcher Sal Jorgenson and the rest of the white-shark tag team have made it past the Golden Gate Bridge only 13.5 out of 25 days so far. They're not too disappointed, though. They've attached 10 pop-up satellite tags to the sharks. Those tags automatically release from the shark after a pre-progammed time.....anywhere from 30 days to a year. Our star white shark, Omoo, wore a pop-up tag for a year, and that's his track that you see on TOPP.org's home page. The taggers also put out 13 acoustic tags. That tag's pretty cool -- it sends data to an array of sensors when the shark swims across them. Arrays lie on the ocean floor off Tomales, Point Reyes, Anno Nuevo, and the Farallons. We'll tell you more about acoustic tags in another post.

In the photo of this very large shark below, the acoustic tag is the smaller of the two. And in the photo below that, that's Sal holding one of the pop-up tags so you can get a feel for the size of the shark. Big.

The winds look reasonable today, so they're out trying their luck again. Anything above 15 knots makes it a little too rock 'n roll to tag the sharks. They put a video camera in the water to record all of their tagging, so that they can identify each shark.They've been doing this for a few years, and they're seeing the same sharks return to the Farallones every year. If you look at the animated map on TOPP's white shark section, you can see how the sharks tagged in 2005 with tags that popped off six to 12 months after they were tagged headed right back to the Gulf of the Farallones after cavorting about in the mysterious "white shark cafe" between Northern California and Hawaii.

Check back over the next few days. We'll be following the tag team over their last six days in the Fall 2007 tagging season. It's a green expedition on the deep blue: they're using a high-tech sailboat to move from San Francisco to the Gulf of the Farallones. We'll tell you more about vessel and crew, and, of course, those terrific sharks.