Hawaii's Great Ocean Predators: Sharks

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HONOLULU STAR-ADVERTISER

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SUNDAY 8/4/13

HAWA HA WAIII’S GREA GREAT T OCEAN OCEAN PREDA PR EDAT TOR ORS S

SHARKS MOST RECENT ATTACKS

There have been five shark attacks in Hawaiian waters this year. 1

2 3 4 5

OAHU

At 4:30 p.m. on Jan. 16, a man was surfing in 10 feet of water about 4 200 yards off Kiholo Bay, Hawaii island, when a 10-foot-long tiger 3 2 shark attacked him. He suffered lacerations to his right forearm and his lower right leg. 5 At about 6 p.m. Feb. 21, Jacob Lansky was surfing about 75 yards offshore of Paia Bay, Maui, when a 6-foot-long reef shark bit the rail of his foam board. Lansky was not injured. At 8:30 a.m. on April 2, a 58-year-old California man visiting Maui was attacked off Kaanapali while surfing. He suffered two deep lacerations on his right thigh. At 2 p.m. Monday, a 19-year-old Kaneohe man was attacked by what was believed to be a tiger shark at White Plains Beach. Kiowa Gatewood underwent emergency surgery. Between 8:30 and 8:45 a.m. Wednesday, a woman was attacked about 30 feet off a rocky point fronting Ulua Beach in Wailea in murky water. The California visitor was taken to Maui Memorial Medical Center and underwent surgery.

MAUI

 ATT  A TTACKS ACKS THROUGH THE YEARS 10 Nonfatal 8 Fatal

1

6 4 2

HAWAII

        0         8         9         1

 ANATOMY  ANA TOMY OF A SHARK  SHARK 

Second dorsal fin

        4         8         9         1

        6         8         9         1

        8         8         9         1

        0         9         9         1

        2         9         9         1

        4         9         9         1

        6         9         9         1

        8         9         9         1

        0         0         0         2

        2         0         0         2

        4         0         0         2

        6         0         0         2

        8         0         0         2

        0         1         0         2

        2         1         0         2

Hearing is apparently directional, which may help sharks find struggling or injured prey. They are sensitive to low-frequency sounds — 10 to 800 hertz (cycles per second). The human hearing range is much greater at about 25 to 16,000 hertz.

First dorsal fin

A shark’s main means of propulsion. Although it differs greatly among species, the fin is always divided into upper and lower lobes. The size of the lobes is key to a shark’s pattern of activity. For instance, a tiger shark’s upper lobe is longer and heavier than the lower. This configuration delivers powerful bursts of speed and quick turns and twists needed to pursue prey. A great white shark, on the other hand, has nearly symmetrical lobes, which deliver enormous thrust.

        2         8         9         1

Ears

The tiger shark is most often involved in attacks in Hawaiian waters. Caudal fin

0

Prevents the shark from rolling over. Appears rigid, but is actually pliable. A shark’s skeleton is made of cartilage, not bone.

Snout Testes

Kidney

Nostrils

Known for its extrordinary sense of smell, a shark can track a scent many miles away.

Upper lobe Lower lobe Eyes

Anal fin

Heart Pelvic fin

Stomach

Liver

IN HAWAIIAN WATERS

The most common sharks found in waters around  the Hawaiian Islands:

Pancreas Gallbladder

Pectoral fin

BLACKTIP REEF SHARK

This active, shallow-water shark is found in lagoons and  on coral reefs and moves with the tide. Not usually  aggressive toward humans. SIZE AT BIRTH: 20 inches MAX. LENGTH: 6 feet HABITAT: Shallow reef flats to outer reef edge DIET: Primarily reef fish WHITETIP REEF SHARK

This sluggish, shallow-water shark is found in caves or  under rocks or coral ledges and is active at night and  during slack tides. Not usually aggressive toward humans. SIZE AT BIRTH: 21-24 inches MAX. LENGTH: 7 feet HABITAT: Shallowwater reef dweller in depths to 1,000 feet DIET: Bottom fish, crustaceans and cephalopods

THE SIXTH SENSE

 In additio addition n to the five five sense senses, s, sharks sharks have a unique unique sixth sens sense e — the abilit abilityy to dete detect ct move-  move-  ment and disturbances from prey or predator even in murky water — through the lateral lines that run along the length of its body. Lateral lines

A pair of sensory tubes filled with a jelly-like substance that extends from the head to caudal fin.

Neuromasts Lateral tube

CHOMP!

Skin

Canal Cilia

They are stimulated by movement and pressure, alerting the shark’s brain to nearby predators or prey.

This potentially aggressive shark does not normally at-  tack humans. Performs a seemingly awkward threat dis-   play befor before e attackin attacking. g. SIZE AT BIRTH: 23-25 inches MAX. LENGTH: 12 feet HABITAT: Just beyond outer reef edge DIET: Reef fish

One of the few true scavenger sharks, it is known to eat  turtles, fish and virtually anything that falls overboard —  cattle, pigs, sheep, humans. It enters shallow reefs and  lagoons at night to feed. Can live for about 12 years.

 A shark’ shark’ss upper upper jaw jaw typically detaches from its skull during  an attack. This loose suspension

Pore

GALAPAGOS SHARK

TIGER SHARK

They are positioned on the side of the shark’s head, creating a wider range of vision than many other animals. The size of the eyes also is an indicator of activity. The sluggish carpetshark,, for incarpetshark stance, has small eyes, suggesting it relies less on sight. A deep-dwelling shark, such as a great white, has extremely large eyes.

SIGNS OF TROUBLE

MISTAKEN IDENTITY

 It has has been been observ observed ed that that when when a shark shark feels feels threa threatene tened d by  other predators or humans who get too close, it exhibits pat-  terns of aggression.

 Scientists theo  Scientists theorize rize that  sharks see silhouettes when hunting from below in deeper water.

20-30 inches 24 feet HABITAT: Beyond the reef’s edge during the day, inshore along coral and rocky reefs at night DIET: Wide-ranging, including seals, birds, carrion, almost anything SIZE AT BIRTH:

1. The

jaw begins to open as the shark attacks...

2. The snout

lifts as the upper jaw protrudes...

Tail cracking:

A shark swims toward a threat, turning suddenly and flicking its tail to produce a loud cracking sound.

MAX. LENGTH:

GREAT WHITE SHARK

The most feared of sharks, it prefers shallow, cool coastal  waters, but occasionally has been seen in Hawaiian wa-  ters. Hunts during the day.

3. The upper jaw

Hunched position:

When approached too closely, a shark will arch its back and push its pectoral fins downward. The snout is also raised with its jaws slightly open.

Side display:

3-4 feet 24 feet HABITAT: Open ocean, tropics to cooler coastal waters DIET: Includes other sharks, dolphins, seals, sea lions, seabirds,, turtles and invertebrates seabirds SIZE AT BIRTH: MAX. LENGTH:

 Sources: “The Little Guides — Sharks,” Sharks,” Cape Cod Times; Florida Sun Sentinel; Sentinel; Hawaiis Hawaiishar harks.c ks.com; om; State Shark Task Task Force

Human surfer

A shark swims in a stiff fashion and follows a figureeight loop when confronted by another shark or predator. It also stretches to its full length to intimidate or establish dominance. If this fails, it attacks.

Sea lion

moves downward and, along with the lower jaw, is simultaneously thrust forward. The moveable eyelid called the nictitating membrane moves upward to protect the eye as the shark feeds...

4. Jaw closes

Sea turtle

again on the prey.

GRAPHIC BY MARTHA HERNANDEZ, BRYANT FUKUTOMI AND DAVID SWANN / STAR-ADVERTISER