Hawaiian Tigers

Although there were 33 attacks on humans in Hawaii during the 1990s, two of them fatal, Ian doesn’t think the Tiger shark’s biology means they could ever make a habit out of killing humans. He concludes that given the choice between humans and a boat cushion, a Tiger shark will take the soft option nearly every time.

Produced by NHNZ

The Hawaiian Island of Oahu has 19 officially-guarded beaches and an estimated 17.5 million visitors a year…..but not all of those visitors are human.

Sharks patrol these waters, the most terrifying of them all, the Tiger shark, the largest of which can reach 18ft (5.4 metres long) long and weigh three tons (3.04 tonnes).

Even the extremely hard shell of an Hawaiian green sea turtle offers no protection against the Tiger shark’s wide jaw and scissor-action teeth.

But Shark Gordon presenter Ian Gordon doesn’t think these sharks deserve their man-eating reputation and he plans to show us why.

There’s no denying attacks do happen. There were 33 shark attacks on humans in Hawaii during the 1990’s, two of them fatal.

But Ian doesn’t think the Tiger sharks’ biology means they could ever make a habit out of killing humans.

He chats to surfer Rick Gruzinsky, who came within 10 inches (25cm) of a Tiger shark as it snapped clean a large chunk of his surfboard. Local shark hunters never did find the culprit but the bite radius on the board indicated that the shark was well over 13ft 10in (4.25 metres).

Control programmes and attempts by hunters to catch attack culprits have lowered the shark population in some areas but Ian doesn’t think these measures work.

Over the last 40 years the rate of attacks has remained constant and what’s been learned only reinforces the Tiger’s reputation.

Ian shows us a few examples of items regularly found in a Tiger shark’s stomach; dogs, beer bottles, coconuts, fishing floats, boat cushions, old rocks, even an unopened can of tuna!

He demonstrates how a phenomenally sharp Tiger shark tooth can easily cut through a tuna can.

Dr Kim Holland from the University of Hawaii believes that these sharks do not actually target humans as food. Kim’s studies show Tiger sharks cover an extremely large territory.

He has been surgically implanting chat tags into Tiger sharks to record their movements. About five times the size of normal tracking tags they can record additional depth and temperature data. A listening post on the sea bed records when a tagged shark comes within range and chats with the tag downloading data the shark has generated.

Ian sets off to help Kim implant this high-tech tracking technology into a live Tiger shark.

The first two sharks caught on the line are too small, but finally a 7ft (2.1 metre) Tiger obliges.

Researchers are unsure why but sharks go into a trance-like state, known as tonic immobility, when rolled over onto their backs. This makes Kim’s job a lot easier.

To Kim’s surprise Ian climbs into the water to assist the dazed animal post operatively.

Ian concludes that given the choice between humans and a boat cushion a Tiger shark would opt for the softer option nearly every time.

There are just two to three shark attacks off Hawaiian beaches a year, mostly non-fatal, compared to 50 or 60 annual drownings.

Considering the millions who use these beaches every year those are pretty good odds.

Episodes From This Series

White Tips of Osprey

30 mins / 2001

A Whale of a Shark

30 mins / 2001

Mako—Friend or Foe?

30 mins / 2001

Great White—The Ultimate Predator

30 mins / 2001

Thresher Shark

30 mins / 2001

Hammerheads

30 mins / 2001

Galapagos Sharks

30 mins / 2001

Grey Nurse — A Visit to the Nurse

30 mins / 2001

Prickly Sharks

30 mins / 2001

Hawaiian Tigers

1 hour / 2001

Port Jackson – A Family Secret

30 mins / 2001

The Sailor’s Nightmare

1 hour / 2001

Shark Attack

30 mins / 2001

Great White Bite

2 Minutes / 2007

Great White – The Ultimate Predator

2 Minutes / 2007

Feeding Frenzy

3 Minutes / 2007

Bull Sharks

3 Minutes / 2007

A Whale of a Shark

2 Minutes / 2007

Mako

3 Minutes / 2007