The headline (Seattle Times/Associated Press, January 31, 2009) was definitely a double-take inducer: “Japan to Tourists: Please Don't Lick the Tuna.”

Definitely grosser than squeezing (or even licking) the Charmin, the mind boggles at what might have inspired this stark (if unfailingly polite — note the “please”) edict. Was there an epidemic of tongue-to-tuna contact that needed to be headed off?

Well, no. Apparently, the headline referred to the actions of one British gent, who was caught on tape by a Japanese TV crew (YouTube immortality awaits) licking the head of a tuna at Tokyo's famous Tsukiji fish market.

His behavior, though extreme (let's hope), is apparently emblematic of how too many tourists behave when go to Tsukiji. The market, famous for its pre-dawn auctions whose rituals go back centuries, is a popular tourist destination.

That's the problem.

The tourists regularly interrupt the proceedings with inane behavior, flashing cameras (which distract bidders) and fingering the expensive product. Since a premium tuna can go for more than $100,000, it is understandable that sellers might not want your fingers — and definitely not your tongue — on the merchandise. Tsukiji briefly barred outsiders earlier this year, but recanted under pressure from tourism officials.

Now, signage in multiple languages setting out the code of conduct has been deployed in hopes of getting better visitor behavior.

One wonders, though, whether a sign, no matter how polite, is effective against a guy willing to lick dead fish in public…