Sharks are the least of James Russell's worries at Kelly Tarlton's.

To be honest, I wasn't expecting to be bitten at the Kelly Tarlton Shark Dive Xtreme, so it came as a big surprise.

As 2.4m-long sand tiger sharks circled overhead, I noticed a swift movement by my ankle. I looked down, and there it was: a blue cod. How cute! I lay down on the sand to say hello. Its eye swivelled wildly in its bony head. I poked out my finger, and - snap! - it bit me.

Would this spill the drop of blood that would incite the feeding frenzy? Would the nice lady and her child waving at us from the viewing tunnel be traumatised for life as a result of my foolhardiness? I looked at my finger. Phew. The skin was unbroken.

I was also a bit worried to learn, earlier that morning, that the 20 sharks in the tank at Kelly Tarlton's are only fed twice a week, and that they were due a feed right after I got out of the tank. Surely that meant that they were at the zenith of their hunger?


"They don't even eat the fish in the tank," said Faust Vercetti, my guide for the day, with an attitude so nonchalant as to be comforting (FYI Kelly Tarlton management: nonchalant maybe, but not unprofessional).

"In fact, that blue cod is the most dangerous fish in there."

It's clear when you enter the tank, the sharks have only a passing interest, probably more for the novelty value than anything else. They do gather around a little bit, and concentrate themselves more down the divers' end of the 30m tank than the other end.

The only shark not making an appearance was the wobbegong, who apparently does his own thing. Curiously, though, he's the only shark which cannot be fed by hand due to his lightning fast strikes at chunks of fish.

The shark population comprises the aforementioned sand tigers (also known as grey nurse sharks), seven gills, the wobbegong and the smaller, but swifter-moving school sharks. The poor old sand tiger, who certainly looks the scariest, is attributed with exactly zero human fatalities worldwide.

I guess they're the same reasons they are the most common sharks to be held in aquaria around the world.

Unfortunately the fins of the sand tiger make some tasty soup, which misguided individuals also believe puts lead in the proverbial pencil. With a low reproduction rate, sand tigers are consequently at risk.

Finally some heartening news came from the shark fin trade recently, with the news that it's on the wane.

Prices and sales of shark fin have fallen in China by 50-70 per cent, according to a report released this month by WildAid. Evidence of Declines in Shark Fin Demand, China compiles public opinion surveys, surveys from shark fin vendors and traders in the markets of Guangzhou, China (the current centre of China's shark fin trade) and surveys of shark fin price data from Indonesian shark fishermen, as well as trade statistics and media reports.

"Demand reduction can be very effective" says Peter Knights, executive director of WildAid.

"The more people learn about the consequences of eating shark-fin soup, the less they want to participate in the trade. Government bans on shark fin at state banquets in China and Hong Kong also helped send the right message."

The shark experience at Kelly Tarlton's also offers the rare chance to take a look at the bowels of the operation, and the monumental 10-month, claustrophobic task Tarlton and his crew faced when turning an old sewage holding tank into an aquarium. In the little tank where shark dive participants learn to purge their mouthpiece and empty their masks, there isn't room to stand up.

Before tank entry, participants sign their lives away, and undergo a Professional Association of Diving Instructors (PADI) certification which takes about half an hour, and actually contributes towards the official PADI Divers' Licence, should you be so inspired.

It's a buzz when the kilograms of weight belts, bulky buoyancy control device and dive tanks suddenly become weightless as you enter the holding tank. As the gate to the shark tank proper is opened, I couldn't help but be reminded of the Happy Days episode where The Fonz readies himself to leap the shark tank on his Harley.

Lowering myself down a rope to the bottom (keep a lookout for shedded sharks' teeth!), where my cod nemesis awaited, was the moment I realised I was in a watery domain where I'm woefully inadequate in every way and, of course, that's where the thrill lies.

It's a great way to appreciate the beauty of sharks - and, of course, stingrays.

Cod - not so much.

Shark Dive Xtreme
Certified divers: $165; walk-up from $132 online
Non certified divers: $230; walk-up, from $184 online
Experience includes: Introduction to SCUBA diving briefing and pool skills session

Cage-free dive with the sharks

All equipment supplied
De-brief and certificate

Kelly Tarlton's Sea Life Aquarium can be found at 23 Tamaki Drive, Orakei, Auckland.