That's the ideal model, and it doesn't always work out. Tags malfunction and the ocean is unpredictable, and a certain number are lost at sea. It happens.
What almost never happens is that a tag written off as MIA suddenly pops back onto the radar. That's why the subject line of this recent e-mail from Julie was simply "!!!":
John O'Sullivan just got a call from a guy in Maui who found one of my tags on the beach--I deployed it in Dec 2009 so it recorded for however long and then floated over there for over a year. Maybe if my model works, we could figure out how far offshore!O'Sullivan is one of Julie's collaborators at the Monterey Bay Aquarium, and this particular tag turned out to have been programmed to record for 17 days. So Julie now has 17 days worth of brand new data from a squid tagged in 2009.HOW COOL!
How cool, indeed.
Julie releasing a tagged squid, photo by Greg Auger